Method and apparatus for controlling battery equalization

Abstract

The embodiment of the application discloses a battery equalization control method and device, and belongs to the technical field of battery pack equalization. The method comprises the following steps: acquiring the single battery voltage of any single battery in a battery pack at a current time and a reference voltage related to the highest single battery voltage in the battery pack; and controlling the single battery to charge according to the single battery voltage and the reference voltage, so that the battery pack reaches battery equalization. The embodiment of the application makes the single battery voltage of the single battery in the battery pack consistent with the highest single battery voltage, reduces the unbalanced situation of the residual power among the single batteries, realizes the residual power equalization among the single batteries, makes the battery pack reach battery equalization, and further prolongs the service life of the battery pack.

Description

Technical Field

[0001] This application relates to the field of battery pack balancing technology, and in particular to a battery balancing control method and apparatus. Background Technology

[0002] With the development of automobiles, electric vehicles are becoming increasingly widely used. The main power source for electric vehicles is the battery pack, which consists of multiple individual cells connected in series. Due to internal differences or varying external usage conditions, the remaining charge of each individual cell in the same battery pack becomes inconsistent with each charge-discharge cycle, leading to battery imbalance and consequently affecting the battery pack's lifespan. Therefore, it is necessary to balance the battery pack. Summary of the Invention

[0003] This application provides a battery balancing control method and apparatus, which can reduce the problem of inconsistent remaining charge among individual cells in a battery pack in related technologies, and extend the service life of the battery pack. The technical solution is as follows:

[0004] On the one hand, a battery balancing control method is provided, the method comprising:

[0005] Obtain the single cell voltage of the target cell in the battery pack at the current moment. The battery pack includes at least one single cell, and the target single cell is any single cell in the battery pack.

[0006] Determine the reference voltage of the target single cell at the current moment, the reference voltage being related to the highest single cell voltage in the battery pack at the current moment;

[0007] Based on the individual cell voltage of the target cell and the reference voltage, the target cell is controlled to be charged so that the battery pack achieves battery balance.

[0008] Optionally, determining the reference voltage of the target single cell at the current moment includes:

[0009] Identify at least one second individual cell that has not been charged within a preset time period from the battery pack;

[0010] The reference voltage of the target cell at the current moment is determined based on the at least one second cell.

[0011] Optionally, determining the reference voltage of the target single cell at the current moment includes:

[0012] The highest single-cell voltage, the battery temperature of the first single-cell battery, and the remaining charge of the first single-cell battery in the battery pack are obtained, wherein the first single-cell battery is the battery corresponding to the highest single-cell voltage.

[0013] Based on the correspondence between the battery temperature, remaining charge, and voltage of a single cell, the first cell voltage corresponding to both the battery temperature and remaining charge of the first cell is determined.

[0014] If the first cell voltage matches the highest cell voltage, then the highest cell voltage is used as the reference voltage.

[0015] Optionally, controlling the charging of the target single cell based on its single cell voltage and the reference voltage includes:

[0016] Determine a first difference between the reference voltage and the individual cell voltage;

[0017] If the first difference is greater than the first voltage threshold, then the target single battery cell is charged;

[0018] If the first difference is not greater than the first voltage threshold, then charging of the target single battery cell is prohibited.

[0019] Optionally, charging the target single battery cell includes:

[0020] During the charging process of the target single battery, it is determined whether the first difference is greater than a second voltage threshold, wherein the second voltage threshold is less than the first voltage threshold;

[0021] If the first difference is greater than the second voltage threshold, the target single battery cell is charged using the first charging mode.

[0022] If the first difference is not greater than the second voltage threshold, the target single battery is charged using the second charging mode, where the charging speed of the first charging mode is greater than the charging speed of the second charging mode.

[0023] Optionally, the method further includes:

[0024] If the target single battery is in a charging state, obtain the change state of the first difference of the target single battery in the charging state;

[0025] If the first difference changes to an increasing value, then charging of the target single battery cell is paused.

[0026] If the first difference changes to a smaller value, then the target single-cell battery continues to be charged.

[0027] On the other hand, a battery balancing control device is provided, the device comprising:

[0028] The first acquisition module is used to acquire the single cell voltage of the target single cell in the battery pack at the current moment. The battery pack includes at least one single cell, and the target single cell is any single cell in the battery pack.

[0029] A determination module is used to determine the reference voltage of the target single cell at the current moment, the reference voltage being related to the highest single cell voltage in the battery pack at the current moment;

[0030] The control module is used to control the charging of the target single cell based on the single cell voltage of the target single cell and the reference voltage, so as to achieve battery equalization of the battery pack.

[0031] Optionally, the determining module includes:

[0032] The first determining submodule is used to determine at least one second individual cell that has not been charged within a preset time period from the battery pack;

[0033] The second determining submodule is used to determine the reference voltage of the target single cell at the current moment based on the at least one second single cell.

[0034] Optionally, the determining module includes:

[0035] The first acquisition submodule is used to acquire the highest single-cell voltage of a single cell in the battery pack, the battery temperature of the first single cell, and the remaining charge of the first single cell, wherein the first single cell is the cell corresponding to the highest single-cell voltage.

[0036] The third determining submodule is used to determine the first cell voltage corresponding to both the battery temperature and the remaining charge of the first cell from the correspondence between the battery temperature, the remaining charge of the first cell, and the cell voltage of the first cell.

[0037] A matching submodule is configured to use the highest single-cell voltage as the reference voltage if the first single-cell voltage matches the highest single-cell voltage.

[0038] Optionally, the control module includes:

[0039] The fourth determining submodule is used to determine the first difference between the reference voltage and the individual cell voltage;

[0040] The first judgment submodule is used to charge the target single battery cell if the first difference is greater than the first voltage threshold.

[0041] The second judgment submodule is used to prohibit charging the target single battery cell if the first difference is not greater than the first voltage threshold.

[0042] Optionally, the first determination submodule includes:

[0043] The first determining unit is used to determine, during the charging process of the target single battery cell, whether the first difference is greater than a second voltage threshold, wherein the second voltage threshold is less than the first voltage threshold.

[0044] The first charging unit is used to charge the target single battery cell using a first charging mode if the first difference is greater than the second voltage threshold.

[0045] The second charging unit is used to charge the target single battery in a second charging mode if the first difference is not greater than the second voltage threshold, wherein the charging speed of the first charging mode is greater than the charging speed of the second charging mode.

[0046] Optionally, the device further includes:

[0047] The second acquisition module is used to acquire the change state of the first difference of the target single cell in the charging state if the target single cell is in a charging state.

[0048] The first charging module is used to pause charging the target single battery cell if the change state of the first difference is that the first difference increases.

[0049] The second charging module is used to continue charging the target single battery cell if the change state of the first difference is that the first difference decreases.

[0050] The beneficial effects of the technical solutions provided in this application include at least the following:

[0051] In this embodiment, by obtaining the individual cell voltage of any cell in the battery pack at the current moment and a reference voltage related to the highest individual cell voltage in the battery pack, the individual cell is controlled to charge based on the individual cell voltage and the reference voltage, thereby making the individual cell voltage of the individual cells in the battery pack more consistent with the highest individual cell voltage, reducing the imbalance of remaining power among the individual cells, thus achieving balance of remaining power among the individual cells, making the battery pack balanced, and thus extending the service life of the battery pack. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a flowchart of a battery balancing control method provided in an embodiment of this application;

[0054] Figure 2 This is a flowchart of another battery equalization control method provided in an embodiment of this application;

[0055] Figure 3 This is a flowchart of a step for determining a reference voltage according to an embodiment of this application;

[0056] Figure 4 This is a flowchart of another step for determining the reference voltage provided in an embodiment of this application;

[0057] Figure 5 This is a flowchart illustrating the steps of charging a target single-cell battery according to an embodiment of this application;

[0058] Figure 6 This is a schematic diagram of the structure of a battery balancing control device provided in an embodiment of this application. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0060] Figure 1 This is a flowchart of a battery balancing control method provided in an embodiment of this application. This control method can be applied to automobiles and may include the following steps:

[0061] Step 101: Obtain the single cell voltage of the target cell in the battery pack at the current time. The battery pack includes at least one single cell, and the target single cell is any single cell in the battery pack.

[0062] Step 102: Determine the reference voltage of the target single cell at the current moment. The reference voltage is related to the highest single cell voltage in the battery pack at the current moment.

[0063] Step 103: Based on the individual cell voltage and reference voltage of the target cell, control the target cell to charge so that the battery pack can achieve battery balance.

[0064] In this embodiment, by obtaining the individual cell voltage of any cell in the battery pack at the current moment and a reference voltage related to the highest individual cell voltage in the battery pack, the individual cell is controlled to charge based on the individual cell voltage and the reference voltage, thereby making the individual cell voltage of the individual cells in the battery pack more consistent with the highest individual cell voltage, reducing the imbalance of remaining power among the individual cells, thus achieving balance of remaining power among the individual cells, making the battery pack balanced, and thus extending the service life of the battery pack.

[0065] Optionally, determining the reference voltage of the target single cell at the current moment includes:

[0066] Identify at least one second cell that has not been charged within a preset time period from the battery pack;

[0067] The reference voltage of the target cell at the current moment is determined based on at least one second cell.

[0068] Optionally, determining the reference voltage of the target single cell at the current moment includes:

[0069] The highest single-cell voltage, the battery temperature of the first single-cell, and the remaining charge of the first single-cell are obtained in the battery pack. The first single-cell is the battery corresponding to the highest single-cell voltage.

[0070] Based on the correspondence between the battery temperature, remaining charge, and voltage of a single cell, the voltage of the first cell corresponding to both the battery temperature and remaining charge of the first cell is determined.

[0071] If the voltage of the first cell matches the voltage of the highest cell, then the voltage of the highest cell is used as the reference voltage.

[0072] Optionally, the target cell is charged based on its individual cell voltage and a reference voltage, including:

[0073] Determine the first difference between the reference voltage and the individual cell voltage;

[0074] If the first difference is greater than the first voltage threshold, the target single cell is charged.

[0075] If the first difference is not greater than the first voltage threshold, charging of the target single cell is prohibited.

[0076] Optionally, charging the target single cell includes:

[0077] During the charging process of the target single cell, it is determined whether the first difference is greater than the second voltage threshold, and the second voltage threshold is greater than the first voltage threshold.

[0078] If the first difference is greater than the second voltage threshold, the first charging mode is used to charge the target single cell.

[0079] If the first difference is not greater than the second voltage threshold, the second charging mode is used to charge the target single battery cell, and the charging speed of the first charging mode is greater than the charging speed of the second charging mode.

[0080] Optionally, the method further includes:

[0081] If the target single cell is in a charging state, obtain the change state of the first difference of the target single cell in the charging state;

[0082] If the first difference changes to an increasing value, then charging of the target single battery cell is paused.

[0083] If the first difference changes to a smaller value, then continue charging the target single cell.

[0084] All of the above-mentioned optional technical solutions can be combined in any way to form optional embodiments of this application, and the embodiments of this application will not be described in detail one by one.

[0085] Figure 2 This is a flowchart of another battery balancing control method provided in this application embodiment. This application embodiment illustrates the application of this control method in a vehicle as an example. The control method may include the following steps:

[0086] Step 201: Obtain the single cell voltage of the target cell in the battery pack at the current moment.

[0087] The battery pack includes at least one individual cell, and the target individual cell is any individual cell in the battery pack. The individual cells in the battery pack are connected in series.

[0088] It should be noted that the individual cell voltage is obtained when the battery pack has no input or output energy.

[0089] In one embodiment of this application, the single cell voltage is the open-circuit voltage or the terminal voltage, and the single cell voltage can be measured by a voltmeter.

[0090] Step 202: Determine the reference voltage of the target single cell at the current moment.

[0091] The reference voltage serves as the basis for adjusting the individual cell voltages of each cell in the battery pack. The individual cell voltages of each cell in the battery pack are adjusted based on the reference voltage to make the individual cell voltages of each cell in the battery pack tend to be consistent. The reference voltage is related to the highest individual cell voltage in the battery pack at the current moment.

[0092] In one embodiment of this application, the reference voltage can be the highest single-cell voltage of a cell in the battery pack at the current moment.

[0093] In another embodiment of this application, the voltage value in the voltage range corresponding to the highest single cell voltage in the battery pack at the current moment can be used as the reference voltage. For example, the voltage range is a range of a preset length with the highest single cell voltage as the middle value. For example, if the highest single cell voltage is V2 and the preset length is 0.1, then the voltage range is [V2-0.05, V1+0.05].

[0094] like Figure 3 As shown, in one embodiment of this application, the reference voltage is determined through steps 2021-2023.

[0095] Step 2021: Obtain the highest single-cell voltage, the battery temperature of the first single-cell, and the remaining charge of the first single-cell in the battery pack.

[0096] The first individual cell is the cell with the highest individual voltage in the battery pack.

[0097] The battery temperature of the first single cell can be obtained by a temperature sensor, and the remaining charge of the first single cell can be obtained by measuring it with a battery measuring device. The remaining charge of the first single cell is used to represent the ratio of the battery's remaining capacity to its capacity in a fully charged state, which can be expressed as a percentage.

[0098] In one embodiment of this application, the individual cell voltage of a single battery can be obtained by measuring with a voltmeter. The highest individual cell voltage is selected from the obtained individual cell voltages. For example, the battery pack includes 5 individual cells: individual cell 1, individual cell 2, individual cell 3, individual cell 4 and individual cell 5. The 5 individual cells are sorted in ascending order of individual cell voltage, and the resulting arrangement is: individual cell 1, individual cell 2, individual cell 3, individual cell 4 and individual cell 5. The individual cell voltage corresponding to individual cell 5 is then taken as the highest individual cell voltage.

[0099] Step 2022: Determine the first cell voltage corresponding to both the battery temperature and the remaining charge of the first cell from the correspondence between the battery temperature, the remaining charge of the first cell, and the cell voltage of the first cell.

[0100] It should be noted that the correspondence can be pre-established based on the historical data of individual batteries. In one embodiment of this application, the correspondence can be a correspondence table or a function relationship, as long as the voltage corresponding to the battery temperature and the remaining battery capacity can be determined through the correspondence.

[0101] Step 2023: If the voltage of the first cell matches the voltage of the highest cell, then the voltage of the highest cell is used as the reference voltage.

[0102] In one embodiment of this application, when the difference between the first cell voltage and the highest cell voltage is less than a preset threshold, it is determined that the first cell voltage matches the highest cell voltage. The preset threshold is set in advance.

[0103] In another embodiment of this application, if the highest single-cell voltage is located within the voltage range corresponding to the first single-cell voltage, then the first single-cell voltage is determined to match the highest single-cell voltage.

[0104] It should be noted that the voltage range of the first unit voltage can be preset according to the actual situation. In one embodiment of this application, the voltage range corresponding to the first unit voltage is a range of preset length with the first unit voltage as the middle value. For example, if the first unit voltage is V1 and the preset length is 0.1, then the voltage range is [V1-0.05, V1+0.05].

[0105] like Figure 4 As shown, in another embodiment of this application, the reference voltage is determined by steps 2024-2025.

[0106] Step 2024: Identify at least one second cell that has not been charged within a preset time period from the battery pack.

[0107] It should be noted that the voltage of a single battery cell will be unstable for a period of time after it has completed charging. Therefore, to ensure the accuracy of the obtained single battery cell voltage, the single battery cell can only be used as a candidate single battery cell for determining the reference voltage after a preset time has elapsed since charging was completed. Thus, the reference voltage needs to be determined based on batteries that have not been charged within the preset time period.

[0108] In this application, the preset time period is a period of time before the current time. The preset time period can be set according to the actual situation. In one embodiment of this application, the preset time period can be 10 seconds.

[0109] Step 2025: Determine the reference voltage of the target cell at the current moment based on at least one second cell.

[0110] In one embodiment of this application, determining the reference voltage of the target single cell at the current moment based on at least one second single cell includes:

[0111] The highest single-cell voltage, the battery temperature of the third single-cell, and the remaining charge of the third single-cell are obtained from at least one second single-cell. The third single-cell is the battery corresponding to the highest single-cell voltage among the single-cell voltages of at least one second single-cell.

[0112] Based on the correspondence between the battery temperature, remaining charge, and voltage of a single cell, the voltage of the third cell corresponding to both the battery temperature and remaining charge of the third cell is determined.

[0113] If the voltage of the third cell matches the voltage of the highest cell, then the voltage of the highest cell will be used as the reference voltage.

[0114] The specific steps for determining the reference voltage of the target single cell at the current moment based on at least one second single cell are similar to the specific steps for determining the reference voltage of the target single cell at the current moment from the battery pack, and will not be repeated here.

[0115] Step 203: Determine the first difference between the reference voltage and the individual cell voltage.

[0116] It should be noted that the first difference is used to characterize the voltage deviation between a single cell and the reference voltage. If the voltage deviation of a single cell is within the preset range, it means that the voltage of the single cell is in a normal state and no adjustment is needed. If the voltage deviation of a single cell is not within the preset range, it means that the voltage of the single cell is in an abnormal state and adjustment is required so that the current voltage of each cell in the battery pack tends to be consistent with the reference voltage.

[0117] Step 204: Determine whether the first difference is greater than the first voltage threshold. If yes, proceed to step 205; otherwise, proceed to step 209.

[0118] In one embodiment of this application, if the first difference is greater than the first voltage threshold, it is determined that the voltage deviation of the target single cell is not within a preset range; if the first difference is not greater than the first voltage threshold, it is determined that the voltage bias of the target single cell is within a preset range.

[0119] In this application, the first voltage threshold can be set according to the actual situation. In one embodiment of this application, the first voltage threshold can be 0.0025V.

[0120] Step 205: Charge the target individual battery cell to achieve battery balance in the battery pack.

[0121] Battery balancing refers to the process by which the remaining charge of each individual cell in the battery pack tends to be consistent.

[0122] In one embodiment of this application, the target single cell can be charged by controlling a controllable switch in a relay until the voltage of the target single cell is consistent with the highest voltage of the battery pack, thus achieving battery balancing.

[0123] The following example illustrates the charging process for a single battery cell:

[0124] The control circuit can simultaneously charge each individual cell in the battery pack. Taking the simultaneous charging of M individual cells as an example, the control circuit includes: N equalization modules and 2×M×N controllable switching devices. The equalization modules control relays to charge the corresponding individual cells. When the remaining power of the i-th cell is detected to be low, the j-th idle equalization module is selected to charge it. Then, the relay controls the intersection point K of the i-th row and j-th column. ij When both switches at the point are closed simultaneously, the equalization module j connects to the individual battery i, initiating charging. Similarly, other equalization modules can simultaneously charge other individual batteries, allowing multiple individual batteries to be charged at the same time.

[0125] In one embodiment of this application, such as Figure 5 As shown, charging the target single cell may include steps 2051-2054.

[0126] Step 2051: During the charging process of the target single cell, obtain the first difference.

[0127] Step 2052: Determine whether the first difference is greater than the second voltage threshold. If yes, proceed to step 2053; otherwise, proceed to step 2054.

[0128] The second voltage threshold is greater than the first voltage threshold. The second voltage threshold can be set according to the actual situation, as long as the second voltage threshold is greater than the first voltage threshold. In one embodiment of this application, the second voltage threshold is 0.01V.

[0129] It should be noted that the charging mode currently adapted to the target single cell is determined by judging whether the first difference is greater than the second voltage threshold, and the current charging mode of the target single cell is updated by the first difference determined in real time.

[0130] In one embodiment of this application, the charging mode includes a fast charging mode and a slow charging mode. The charging mode is adjusted by controlling the magnitude of the charging current. The charging current corresponding to the charging mode is determined by the product of the current adjustment parameter and the first difference. The magnitude of the current adjustment parameter is different for each charging mode. The charging mode is controlled by selecting the current adjustment parameter corresponding to the current.

[0131] In one embodiment of this application, the current adjustment parameter for fast charging mode is a first value, and the current adjustment parameter for slow charging mode is a second value, wherein the first value is greater than the second value, for example, the first value is 1 and the second value is 0.5. In another embodiment of this application, the first value is a preset multiple of the second value, for example, the first value is twice the second value.

[0132] Step 2053: Charge the target single battery cell using the first charging mode.

[0133] The first charging mode is the fast charging mode.

[0134] Step 2054: Charge the target single cell using the second charging mode.

[0135] The charging speed of the first charging mode is greater than that of the second charging mode. In one embodiment of this application, the second charging mode is a slow charging mode.

[0136] Step 206: If the target single cell is in a charging state, obtain the change state of the first difference of the target single cell in the charging state.

[0137] It should be noted that during the charging process, if the charging state is normal, the voltage of the target single cell should be higher than before, while the reference voltage is generally stable and almost unchanged. Therefore, the first difference should be lower. Conversely, if the first difference is higher, it indicates an abnormal charging state.

[0138] The change state of the first difference is used to characterize the trend of change of the first difference, which can be an upward trend or a downward trend. In one embodiment of this application, the change state of the first difference can be acquired in real time or periodically.

[0139] Step 207: If the change state of the first difference is that the first difference increases, then suspend charging of the target single battery cell.

[0140] In one embodiment of this application, when the first difference increases, the charging state is considered abnormal, and charging of the target single battery can be suspended to ensure safety. In another embodiment of this application, to ensure the accuracy of determining the charging abnormality, the charging state is only determined to be abnormal when the value of the first difference increases to a preset value, and charging of the target single battery is suspended in the abnormal charging state.

[0141] To enable users to promptly obtain information about abnormal charging conditions, fault information can be reported when charging of a target individual battery is paused.

[0142] Step 208: If the change state of the first difference is that the first difference decreases, then continue charging the target single cell.

[0143] It should be noted that, to allow users to more intuitively observe the state of the first difference, a curve showing the change in the first difference can be plotted and displayed based on the obtained first difference. Since the first difference only characterizes the change in the difference between the individual cell voltage and the reference voltage, and cannot accurately determine the change in the individual cell voltage and the reference voltage during the charging process, a single-cell voltage curve for the target battery cell can be plotted and displayed based on the obtained individual cell voltage, and a reference voltage curve can be plotted and displayed based on the obtained reference voltage.

[0144] Step 209 then prohibits charging the target individual battery cell.

[0145] In this embodiment, by obtaining the individual cell voltage of any cell in the battery pack at the current moment and a reference voltage related to the highest individual cell voltage in the battery pack, the individual cell is controlled to charge based on the individual cell voltage and the reference voltage, thereby making the individual cell voltage of the individual cells in the battery pack more consistent with the highest individual cell voltage, reducing the imbalance of remaining power among the individual cells, thus achieving balance of remaining power among the individual cells, making the battery pack balanced, and thus extending the service life of the battery pack.

[0146] Figure 6 This is a schematic diagram of a battery balancing control device provided in an embodiment of this application. The battery balancing control device can be implemented by software, hardware, or a combination of both. The vehicle control device may include: a first acquisition module 601, a determination module 602, and a control module 603.

[0147] The first acquisition module 601 is used to acquire the single cell voltage of the target single cell in the battery pack at the current moment. The battery pack includes at least one single cell, and the target single cell is any single cell in the battery pack.

[0148] The determination module 602 is used to determine the reference voltage of the target single cell at the current moment. The reference voltage is related to the highest single cell voltage in the battery pack at the current moment.

[0149] The control module 603 is used to control the charging of the target single cell based on the single cell voltage and the reference voltage, so as to achieve battery balance in the battery pack.

[0150] Optionally, module 602 includes:

[0151] The first determining submodule is used to determine at least one second single cell that has not been charged within a preset time period from the battery pack;

[0152] The second determining submodule is used to determine the reference voltage of the target single cell at the current moment based on at least one second single cell.

[0153] Optionally, module 602 includes:

[0154] The first acquisition submodule is used to acquire the highest single cell voltage, the battery temperature of the first single cell, and the remaining charge of the first single cell in the battery pack. The first single cell is the battery corresponding to the highest single cell voltage.

[0155] The third determining submodule is used to determine the first cell voltage corresponding to both the battery temperature and the remaining charge of the first cell from the correspondence between the battery temperature, the remaining charge of the first cell, and the cell voltage of the first cell.

[0156] The matching submodule is used to use the highest cell voltage as the reference voltage if the first cell voltage matches the highest cell voltage.

[0157] Optionally, the control module 603 includes:

[0158] The fourth determination submodule is used to determine the first difference between the reference voltage and the individual cell voltage;

[0159] The first judgment submodule is used to charge the target single cell if the first difference is greater than the first voltage threshold.

[0160] The second judgment submodule is used to prohibit charging of the target single battery cell if the first difference is not greater than the first voltage threshold.

[0161] Optionally, the first judgment submodule includes:

[0162] The first determining unit is used to determine whether a first difference is greater than a second voltage threshold during the charging process of the target single cell, wherein the second voltage threshold is greater than the first voltage threshold.

[0163] The first charging unit is used to charge the target single cell battery using a first charging mode if the first difference is greater than the second voltage threshold.

[0164] The second charging unit is used to charge the target single battery in a second charging mode if the first difference is not greater than the second voltage threshold, wherein the charging speed of the first charging mode is greater than the charging speed of the second charging mode.

[0165] Optionally, the device further includes:

[0166] The second acquisition module is used to acquire the change state of the first difference of the target single cell in the charging state if the target single cell is in the charging state.

[0167] The first charging module is used to pause charging the target single battery cell if the change state of the first difference is that the first difference increases.

[0168] The second charging module is used to continue charging the target single battery cell if the change state of the first difference is that the first difference decreases.

[0169] In this embodiment, by obtaining the individual cell voltage of any cell in the battery pack at the current moment and a reference voltage related to the highest individual cell voltage in the battery pack, the individual cell is controlled to charge based on the individual cell voltage and the reference voltage, thereby making the individual cell voltage of the individual cells in the battery pack more consistent with the highest individual cell voltage, reducing the imbalance of remaining power among the individual cells, thus achieving balance of remaining power among the individual cells, making the battery pack balanced, and thus extending the service life of the battery pack.

[0170] It should be noted that the battery balancing control device provided in the above embodiments is only illustrated by the division of the above functional modules when controlling a vehicle. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the battery balancing control device and the battery balancing control method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0171] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present application should be included within the protection scope of the present application.

Claims

1. A battery equalization control method, characterized in that, The method includes: Obtain the single cell voltage of the target cell in the battery pack at the current moment. The battery pack includes at least one single cell, and the target single cell is any single cell in the battery pack. Determine the reference voltage of the target single cell at the current moment, the reference voltage being related to the highest single cell voltage in the battery pack at the current moment; Based on the individual cell voltage of the target cell and the reference voltage, the target cell is controlled to be charged so that the battery pack achieves battery balance. Determining the reference voltage of the target single cell at the current moment includes: The highest single-cell voltage, the battery temperature of the first single-cell battery, and the remaining charge of the first single-cell battery in the battery pack are obtained, wherein the first single-cell battery is the battery corresponding to the highest single-cell voltage. Based on the correspondence between the battery temperature, remaining charge, and voltage of a single cell, the first cell voltage corresponding to both the battery temperature and remaining charge of the first cell is determined. If the first cell voltage matches the highest cell voltage, then the highest cell voltage is used as the reference voltage; the matching of the first cell voltage and the highest cell voltage includes: if the difference between the first cell voltage and the highest cell voltage is less than a preset threshold, then the first cell voltage is determined to match the highest cell voltage; or, if the highest cell voltage is located within the voltage range corresponding to the first cell voltage, then the first cell voltage is determined to match the highest cell voltage.

2. The method according to claim 1, characterized in that, Determining the reference voltage of the target single cell at the current moment includes: Identify at least one second individual cell that has not been charged within a preset time period from the battery pack; The reference voltage of the target cell at the current moment is determined based on the at least one second cell.

3. The method according to claim 1, characterized in that, The step of controlling the charging of the target single cell based on its single cell voltage and the reference voltage includes: Determine a first difference between the reference voltage and the individual cell voltage; If the first difference is greater than the first voltage threshold, then the target single battery cell is charged; If the first difference is not greater than the first voltage threshold, then charging of the target single battery cell is prohibited.

4. The method according to claim 3, characterized in that, The charging of the target single battery cell includes: During the charging process of the target single battery, it is determined whether the first difference is greater than a second voltage threshold, wherein the second voltage threshold is greater than the first voltage threshold. If the first difference is greater than the second voltage threshold, the target single battery cell is charged using the first charging mode. If the first difference is not greater than the second voltage threshold, the target single battery is charged using the second charging mode, where the charging speed of the first charging mode is greater than the charging speed of the second charging mode.

5. The method according to claim 3, characterized in that, The method further includes: If the target single battery is in a charging state, obtain the change state of the first difference of the target single battery in the charging state; If the first difference changes to an increasing value, then charging of the target single battery cell is paused. If the first difference changes to a smaller value, then the target single-cell battery continues to be charged.

6. A battery equalization control device, characterized in that, The device includes: The first acquisition module is used to acquire the single cell voltage of the target single cell in the battery pack at the current moment. The battery pack includes at least one single cell, and the target single cell is any single cell in the battery pack. A determination module is used to determine the reference voltage of the target single cell at the current moment, the reference voltage being related to the highest single cell voltage in the battery pack at the current moment; The control module is used to control the target single cell to charge according to the single cell voltage of the target single cell and the reference voltage, so as to achieve battery balance in the battery pack; The determining module includes: The first acquisition submodule is used to acquire the highest single-cell voltage, the battery temperature of the first single-cell battery, and the remaining charge of the first single-cell battery in the battery pack, wherein the first single-cell battery is the battery corresponding to the highest single-cell voltage. The third determining submodule is used to determine the first cell voltage corresponding to both the battery temperature and the remaining charge of the first cell from the correspondence between the battery temperature, the remaining charge of the first cell, and the cell voltage of the first cell. The matching submodule is used to determine that the first cell voltage and the highest cell voltage are matched if the difference between the first cell voltage and the highest cell voltage is less than a preset threshold; or, if the highest cell voltage is within the voltage range corresponding to the first cell voltage, then determine that the first cell voltage and the highest cell voltage are matched. The matching submodule is configured to use the highest single-cell voltage as the reference voltage if the first single-cell voltage matches the highest single-cell voltage.

7. The apparatus according to claim 6, characterized in that, The determining module includes: The first determining submodule is used to determine at least one second individual cell that has not been charged within a preset time period from the battery pack; The second determining submodule is used to determine the reference voltage of the target single cell at the current moment based on the at least one second single cell.

8. The apparatus according to claim 6, characterized in that, The control module includes: The fourth determining submodule is used to determine the first difference between the reference voltage and the individual cell voltage; The first judgment submodule is used to charge the target single battery cell if the first difference is greater than the first voltage threshold. The second judgment submodule is used to prohibit charging the target single battery cell if the first difference is not greater than the first voltage threshold.

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