Cell balancing methods, apparatus, electronic devices and computer-readable storage media

Abstract

This application provides a cell balancing method, apparatus, electronic device, and computer-readable storage medium. The method includes: for each target state, when the power battery is in that state, acquiring the first voltage of each individual cell in the power battery, sorting the individual cells in descending order of the first voltage to obtain a first arrangement order of each individual cell in that state; selecting a first preset number of individual cells from all individual cells according to the first arrangement order of each individual cell in that state, and labeling the selected individual cells once using the first arrangement order of each individual cell in that state; counting the number of labels for each individual cell, and determining the individual cell as the first cell to be balanced when the number of labels for the individual cell is greater than a preset number; and performing discharge balancing on the first cell to be balanced. This method improves the lifespan and safety of each cell in the power battery.

Description

Technical Field

[0001] This application relates to the field of electric vehicle technology, and in particular to a cell balancing method, apparatus, electronic device, and computer-readable storage medium. Background Technology

[0002] With the gradual promotion of new energy vehicles, the core component of these vehicles, the power battery, has received widespread attention. Since the cost of the power battery accounts for a significant portion of the overall vehicle cost, its performance and lifespan have become key concerns for consumers. Towards the end of the charging process, the cells that reach the voltage threshold first may experience transient overvoltage. Considering system safety, the industry practice is to lower the voltage threshold, reserving a sufficient safety margin at the end of charging by sacrificing some cell performance.

[0003] Meanwhile, in actual charging scenarios, the cells that first reach the voltage threshold during each charge are usually a specific one or a few cells. The transient high voltage at the end of charging makes these cells potential failure points, which may lead to lifespan degradation or safety risks later on. Other cells in the power battery may not undergo full-charge activation for an extended period, resulting in decreased power performance. This is especially true in PHEV models, which are often subjected to shallow charging and discharging conditions. Even with external power replenishment, the inconsistency among cells means that while some cells are fully charged, the voltage of the others may not reach the full-charge threshold. This leads to a decrease in lithium-ion insertion and desorption performance, affecting the battery system's power performance and potentially requiring manual repair, increasing after-sales costs. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a cell balancing method, apparatus, electronic device and computer-readable storage medium, which improves the life and safety of each cell in the power battery by discharging and balancing the cell with the highest voltage in the power battery to avoid the safety risk of long-term and repeated transient overcharging of a specific cell.

[0005] In a first aspect, embodiments of this application provide a cell balancing method, including:

[0006] For each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state; the target state includes charging state, static state, and discharging state;

[0007] Based on the first arrangement order of each individual cell in this state, select the first preset number of individual cells from all the individual cells, and use the first arrangement order of each individual cell in this state to label the selected individual cells once.

[0008] For each individual battery cell, the number of times the individual battery cell is marked is counted. When the number of times the individual battery cell is marked is greater than a preset number, the individual battery cell is identified as the first battery cell to be balanced. The preset number is determined by the number of states in the target state. The preset number is less than or equal to the number of states in the target state.

[0009] Discharge equalization is performed on the first cell to be equalized. When the preset discharge equalization condition is reached, the discharge equalization of the first cell to be equalized is stopped.

[0010] In conjunction with the first aspect, this application provides a first possible implementation of the first aspect, wherein, for each of the target states, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted according to the first voltage from high to low to obtain a first arrangement order of each individual cell in that state, including:

[0011] Based on the equalization time interval of the power battery, determine whether the current equalization cycle has been reached at the current moment;

[0012] When the current time reaches the current equilibrium cycle, for each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state.

[0013] In conjunction with the first possible implementation of the first aspect, this application provides a second possible implementation of the first aspect, wherein the step of performing discharge equalization on the first cell to be equalized, and stopping the discharge equalization of the first cell to be equalized when a preset discharge equalization condition is reached, includes:

[0014] During the charging process of the power battery, each of the first cells to be balanced is discharged, and the current second voltage of each individual cell is detected in real time during the discharge process of the first cells to be balanced.

[0015] The individual battery cells are sorted according to the second voltage from high to low to obtain a second arrangement order for each individual battery cell;

[0016] Determine whether the second arrangement order of the first cell to be balanced is within the first preset number. If the second arrangement order of the first cell to be balanced is not within the first preset number, stop the discharge balancing of the first cell to be balanced.

[0017] In conjunction with the first aspect, this application provides a third possible implementation of the first aspect, wherein the method further includes:

[0018] During use, the battery temperature and the external ambient temperature of the power battery are collected.

[0019] Based on the battery temperature and the external ambient temperature of the power battery, the initial temperature field model of the power battery is corrected to obtain the corrected temperature field model; wherein, the initial temperature field model is determined before the power battery leaves the factory.

[0020] Based on the temperature field model, in order of the individual cell temperature from high to low, select the individual cells with the highest and second-most preset temperatures from all the individual cells in the power battery, and use the selected individual cells as candidate cells to be equalized.

[0021] For each individual battery cell, the difference between the capacity of that individual battery cell and the capacity of each other individual battery cell is calculated to obtain the capacity difference between that individual battery cell and each other individual battery cell.

[0022] When the single cell is the candidate cell to be balanced, if at least one of the capacity differences corresponding to the single cell is greater than the first value, then the single cell is determined as the second cell to be balanced; wherein, the first value is equal to the product of the first percentage value and the nominal capacity of the single cell;

[0023] When the individual cell is not one of the candidate cells to be balanced, if at least one of the capacity differences corresponding to the individual cell is greater than the second value, then the individual cell is determined as the second cell to be balanced; wherein, the second value is equal to the product of the second percentage value and the nominal capacity of the individual cell; the second percentage value is greater than the first percentage value.

[0024] Cell balancing is performed on the second cell to be balanced.

[0025] In conjunction with the third possible implementation of the first aspect, this application provides a fourth possible implementation of the first aspect, wherein the cell balancing of the second cell to be balanced includes:

[0026] During the charging process, the third voltage of each individual cell is detected, and the individual cells are sorted in descending order of the third voltage to obtain the third arrangement order of each individual cell.

[0027] For each of the second cells to be balanced, when the third arrangement order of the second cells to be balanced is in the first third preset number, the second cells to be balanced are discharged and balanced until the third voltage of the second cells to be balanced is reduced to the current average voltage of the individual cells, and then the discharge and equalization of the second cells to be balanced is stopped.

[0028] When the third arrangement of the second cell to be balanced is the third preset number of cells, the second cell to be balanced is charged until its third voltage reaches the current average voltage of the individual cell, at which point the charging of the second cell to be balanced stops; or, the other individual cells are discharged until their third voltage reaches the current average voltage of the individual cell, at which point the discharge of the other individual cells stops.

[0029] Secondly, embodiments of this application also provide a cell balancing device, comprising:

[0030] The first acquisition module is used to acquire the first voltage of each individual cell in the power battery for each state in the target state. When the power battery is in the target state, the individual cells are sorted in order of the first voltage from high to low to obtain the first arrangement order of each individual cell in the target state. The target state includes charging state, static state, and discharging state.

[0031] The first selection module is used to select the first preset number of individual cells from all the individual cells according to the first arrangement order of each individual cell in the current state, and to use the first arrangement order of each individual cell in the current state to label the selected individual cells once.

[0032] The statistics module is used to count the number of times each individual battery cell is marked. When the number of times an individual battery cell is marked is greater than a preset number, the individual battery cell is identified as the first battery cell to be balanced. The preset number is determined by the number of states in the target state. The preset number is less than or equal to the number of states in the target state.

[0033] The first equalization module is used to perform discharge equalization on the first cell to be equalized. When the preset discharge equalization condition is reached, the discharge equalization of the first cell to be equalized is stopped.

[0034] In conjunction with the second aspect, this application provides a first possible implementation of the second aspect, wherein the first acquisition module, when acquiring the first voltage of each individual cell in the power battery for each state in the target state, and sorting the individual cells according to the first voltage from high to low to obtain the first arrangement order of each individual cell in that state, is specifically used for:

[0035] Based on the equalization time interval of the power battery, determine whether the current equalization cycle has been reached at the current moment;

[0036] When the current time reaches the current equilibrium cycle, for each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state.

[0037] In conjunction with the second aspect, this application provides a second possible implementation of the second aspect, wherein, when the first equalization module is used to perform discharge equalization on the first cell to be equalized, and stops discharging equalization on the first cell to be equalized when a preset discharge equalization condition is reached, it is specifically used for:

[0038] During the charging process of the power battery, each of the first cells to be balanced is discharged, and the current second voltage of each individual cell is detected in real time during the discharge process of the first cells to be balanced.

[0039] The individual battery cells are sorted according to the second voltage from high to low to obtain a second arrangement order for each individual battery cell;

[0040] Determine whether the second arrangement order of the first cell to be balanced is within the first preset number. If the second arrangement order of the first cell to be balanced is not within the first preset number, stop the discharge balancing of the first cell to be balanced.

[0041] In conjunction with the second aspect, this application provides a third possible implementation of the second aspect, wherein the apparatus further includes:

[0042] The second acquisition module is used to acquire the battery temperature and the external ambient temperature of the power battery during use.

[0043] The correction module is used to correct the initial temperature field model of the power battery based on the battery temperature and the external ambient temperature to obtain the corrected temperature field model; wherein the initial temperature field model is determined before the power battery leaves the factory.

[0044] The second selection module is used to select, based on the temperature field model, individual cells whose temperatures are in the top second preset number from all the individual cells in the power battery in descending order of individual cell temperature, so as to use the selected individual cells as candidate cells to be balanced.

[0045] The calculation module is used to calculate the difference between the capacity of each individual cell and the capacity of each other individual cell for each individual cell, so as to obtain the capacity difference between the individual cell and each other individual cell.

[0046] The first determining module is used to determine the single cell as the second cell to be balanced when the single cell is the candidate cell to be balanced, if at least one capacity difference among the corresponding capacity differences of the single cell is greater than a first value; wherein, the first value is equal to the product of the first percentage value and the nominal capacity of the single cell;

[0047] The second determining module is used to determine the single cell as the second cell to be balanced when the single cell is not one of the candidate cells to be balanced, if at least one of the capacity differences corresponding to the single cell is greater than a second value; wherein the second value is equal to the product of the second percentage value and the nominal capacity of the single cell; the second percentage value is greater than the first percentage value.

[0048] The second balancing module is used to perform cell balancing on the second cell to be balanced.

[0049] In conjunction with the third possible implementation of the second aspect, this application provides a fourth possible implementation of the second aspect, wherein the second equalization module, when used to perform cell equalization on the second cell to be equalized, is specifically used for:

[0050] During the charging process, the third voltage of each individual cell is detected, and the individual cells are sorted in descending order of the third voltage to obtain the third arrangement order of each individual cell.

[0051] For each of the second cells to be balanced, when the third arrangement order of the second cells to be balanced is in the first third preset number, the second cells to be balanced are discharged and balanced until the third voltage of the second cells to be balanced is reduced to the current average voltage of the individual cells, and then the discharge and equalization of the second cells to be balanced is stopped.

[0052] When the third arrangement of the second cell to be balanced is the third preset number of cells, the second cell to be balanced is charged until its third voltage reaches the current average voltage of the individual cell, at which point the charging of the second cell to be balanced stops; or, the other individual cells are discharged until their third voltage reaches the current average voltage of the individual cell, at which point the discharge of the other individual cells stops.

[0053] Thirdly, embodiments of this application also provide an electronic device, including: a processor, a memory, and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the memory via the bus, and when the machine-readable instructions are executed by the processor, the steps in any of the possible implementations of the first aspect described above are performed.

[0054] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps in any of the possible implementations of the first aspect described above.

[0055] This application provides a cell balancing method, apparatus, electronic device, and computer-readable storage medium. The method involves determining that the first voltage of a first cell to be balanced is higher than the first voltage of other individual cells. Therefore, by performing discharge balancing on the first cell to be balanced, the first voltage of the first cell to be balanced is reduced, narrowing the difference between the first point voltage of the first cell to be balanced and the first point voltage of other individual cells. This avoids the safety risk of repeated transient overcharging of the first cell to be balanced over a long period, and improves the lifespan and safety of each individual cell in the power battery.

[0056] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0057] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 A flowchart of a cell balancing method provided in an embodiment of this application is shown;

[0059] Figure 2A flowchart of another cell balancing method provided in an embodiment of this application is shown;

[0060] Figure 3 This paper shows a schematic diagram of the structure of a cell equalization device provided in an embodiment of this application;

[0061] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0063] Considering that in actual charging scenarios, the first cells to reach the voltage threshold during each charge are usually a specific one or a few cells, the transient high voltage at the end of charging makes these cells potential failure points, which may lead to lifespan degradation or safety risks later on. There is also the problem of other cells in the power battery not being fully charged and activated for a long time, resulting in a decrease in the power performance of the cells. Based on this, embodiments of this application provide a cell balancing method, apparatus, electronic device, and computer-readable storage medium, which are described below through embodiments.

[0064] To facilitate understanding of this embodiment, a cell balancing method disclosed in this application will first be described in detail. For example... Figure 1 As shown, the process includes the following steps S101-S104:

[0065] S101: For each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state; the target states include charging state, static state, and discharging state.

[0066] In this embodiment, during the charging and discharging process of the power battery, the voltage of the individual cells will show obvious inconsistencies. At this time, it is necessary to identify the individual cells that need to be balanced based on the voltage distribution of the individual cells in the power battery.

[0067] Specifically, during the charging process of the power battery, that is, when the power battery is in the charging state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in the charging state.

[0068] Similarly, when the power battery is in a static state (neither charging nor discharging), the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in descending order of the first voltage to obtain the first arrangement order of each individual cell in the static state.

[0069] During the discharge process of the power battery, that is, when the power battery is in a discharge state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in the discharge state.

[0070] In this way, each individual cell corresponds to three first arrangement sequences.

[0071] S102: Based on the first arrangement order of each individual cell in this state, select the first preset number of individual cells from all individual cells, and use the first arrangement order of each individual cell in this state to label the selected individual cells once.

[0072] In this embodiment, the first preset quantity is determined by the total number of all individual battery cells. Specifically, the first preset quantity can be a preset multiple of the total number of individual battery cells, and the value of the preset multiple is greater than 0 and less than 1. For example, when the preset multiple is 1 / 3, the first preset quantity is equal to 1 / 3 of the total number of individual battery cells. For instance, when the total number of individual battery cells is 3n, the first preset quantity is n.

[0073] When the power battery is in the charging state, according to the first arrangement order of each individual cell in the charging state, the first preset number of individual cells are selected from all individual cells, and the selected individual cells are labeled once using the first arrangement order of each individual cell in the charging state.

[0074] For example, when the power battery is charging, the first n cells are selected from 3n cells based on their initial arrangement during charging. These selected cells are then labeled using the same initial arrangement. Specifically, they are labeled CELL1, CELL2, CELL3, ..., CELLn according to their initial voltage during charging, from highest to lowest.

[0075] When the power battery is in a static state, according to the first arrangement order of each individual cell in the static state, the first preset number of individual cells are selected from all individual cells, and the selected individual cells are labeled using the first arrangement order of each individual cell in the charging state.

[0076] For example, when the power battery is in a static state, based on the first arrangement order of each individual cell in the charging state, the first n individual cells are selected from 3n individual cells. These selected first n individual cells are then labeled using the first arrangement order of each individual cell in the static state. That is, the individual cells are labeled CELL1, CELL2, CELL3, ..., CELLn according to their first voltage in the static state, from highest to lowest.

[0077] When the power battery is in a discharging state, according to the first arrangement order of each individual cell in the discharging state, the first preset number of individual cells are selected from all individual cells, and the selected individual cells are labeled once using the first arrangement order of each individual cell in the charging state.

[0078] For example, when the power battery is in a discharging state, based on the first arrangement order of each cell in the charging state, the first n cells are selected from 3n cells. These selected cells are then labeled using the first arrangement order of each cell in the discharging state. That is, the cells are labeled CELL1, CELL2, CELL3..., CELLn according to their first voltage in the discharging state, from highest to lowest.

[0079] S103: For each individual cell, count the number of times the individual cell is marked. When the number of times the individual cell is marked is greater than the preset number, the individual cell is determined as the first cell to be balanced. The preset number is determined by the number of states in the target state. The preset number is less than or equal to the number of states in the target state.

[0080] In this embodiment, the number of times a single battery cell is labeled refers to the number of times the single battery cell is labeled simultaneously in several of the three states. Since the target state includes three states, the maximum number of times each single battery cell can be labeled is three.

[0081] For example, if a single cell A is marked once in a static state, once in a discharging state, and not marked in a charging state, then the number of times the single cell A is marked is twice.

[0082] When the preset number of times is 1, the number of times that cell A is marked (2 times) is greater than the preset number of times. At this time, cell A can be identified as the first cell to be balanced.

[0083] S104: Perform discharge equalization on the first cell to be equalized. When the preset discharge equalization condition is reached, stop the discharge equalization of the first cell to be equalized.

[0084] In this embodiment, during the charging process of the power battery, the first cell to be balanced is discharged to reduce the first voltage of the first cell to be balanced and reduce the difference between the first point voltage of the first cell to be balanced and the first point voltage of other individual cells.

[0085] In one possible implementation, step S101 can be performed according to the following steps:

[0086] Based on the equalization time interval of the power battery, determine whether the current equalization cycle has been reached at the current moment;

[0087] When the current moment reaches the current equilibrium cycle, for each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state.

[0088] In this embodiment, periodic cell balancing is performed on each individual cell in the power battery, that is, cell balancing is performed once every certain period of time.

[0089] In one possible implementation, when performing step S104, the following steps S1041-S1043 can be specifically performed:

[0090] S1041: During the charging process of the power battery, each first cell to be balanced is discharged, and during the discharge process of the first cell to be balanced, the current second voltage of each individual cell is detected in real time.

[0091] S1042: Sort the individual cells according to the second voltage from high to low to obtain the second arrangement order of each individual cell.

[0092] S1043: Determine whether the second arrangement order of the first cell to be balanced is within the first preset number. When the second arrangement order of the first cell to be balanced is not within the first preset number, stop the discharge balancing of the first cell to be balanced.

[0093] For example, following the aforementioned embodiment, when the number of individual battery cells is 3n and the first preset number is n, it is determined whether the second arrangement order of the first battery cell to be balanced is in the first n, that is, whether it is in the first 1 / 3 sequence. When the second arrangement order of the first battery cell to be balanced is not in the first n, the discharge balancing of the first battery cell to be balanced is stopped.

[0094] As can be seen, in this embodiment, after identifying the first cell to be balanced, discharge balancing is performed on it during its charging process. During this process, the second voltage of all individual cells is detected. Balancing stops when the second voltage of the first cell to be balanced is not in the first preset number (e.g., not in the first 1 / 3). After balancing, the first cell to be balanced is in a lower voltage range, while other cells with lower voltages become cells with higher voltages. In subsequent charging, these cells can be charged to full voltage, thus activating their electrochemical performance. Performing discharge balancing periodically ensures that each cell has a chance to be fully charged, thereby distributing the risk of overvoltage from slow charging to each cell in the battery, thus delaying cell lifespan degradation.

[0095] In one possible implementation, such as Figure 2 As shown, the second cell to be balanced can also be identified through the following steps S201-S207:

[0096] S201: During the use of the power battery, the battery temperature and the external ambient temperature are collected.

[0097] In this embodiment, "power battery in use" refers to the electric vehicle equipped with the power battery during its operation. "Ambient temperature" refers to the temperature of the external environment in which the power battery is located.

[0098] S202: Based on the battery temperature and the external ambient temperature, the initial temperature field model of the power battery is corrected to obtain the corrected temperature field model; wherein, the initial temperature field model is determined before the power battery leaves the factory.

[0099] In this embodiment, the initial temperature field model of the power batteries produced in the same batch is the same. Considering that there are some differences between different power batteries, in this embodiment, the initial temperature field model is corrected by using the battery temperature of the power battery itself and the external ambient temperature, so that the obtained temperature field model is more targeted.

[0100] S203: Based on the temperature field model, select the cells with the highest to lowest temperatures from all cells in the power battery, and use these selected cells as candidate cells to be balanced.

[0101] In this embodiment, a single cell with a higher temperature is selected as a candidate cell to be balanced using a temperature field model.

[0102] S204: For each individual cell, calculate the difference between the capacity of that individual cell and the capacity of each other individual cell to obtain the capacity difference between that individual cell and each other individual cell.

[0103] S205: When the single cell is a candidate cell to be balanced, if at least one of the capacity differences corresponding to the single cell is greater than the first value, then the single cell is determined as the second cell to be balanced; wherein, the first value is equal to the product of the first percentage value and the nominal capacity of the single cell.

[0104] S206: When the single cell is not a candidate cell to be balanced, if at least one of the capacity differences corresponding to the single cell is greater than the second value, then the single cell is determined as the second cell to be balanced; wherein, the second value is equal to the product of the second percentage value and the nominal capacity of the single cell; the second percentage value is greater than the first percentage value.

[0105] In this embodiment, the nominal capacity is a fixed value. The first percentage value can be 5%, and the second percentage value can be 10%.

[0106] S207: Perform cell balancing on the second cell to be balanced.

[0107] In one possible implementation, when performing step S207, the following steps S2071-S2073 can be specifically performed:

[0108] S2071: During the charging process of the power battery, the third voltage of each individual cell is detected, and the individual cells are sorted in order from high to low according to the third voltage to obtain the third arrangement order of each individual cell.

[0109] S2072: For each second cell to be balanced, when the third arrangement order of the second cell to be balanced is in the first third preset number, discharge balancing is performed on the second cell to be balanced until the third voltage of the second cell to be balanced drops to the current average voltage of the individual cell, then discharge balancing is stopped on the second cell to be balanced.

[0110] For example, when the total number of individual battery cells is 30, the third preset number can be 6, that is, the third preset number is equal to 20% multiplied by the total number of individual battery cells.

[0111] In this example, when the third arrangement of the second cell to be balanced is in the first 6 (i.e. in the first 20%), it means that the second cell to be balanced needs to be discharged to reduce the third voltage of the second cell to be balanced.

[0112] S2073: When the third arrangement of the second cell to be balanced is the third preset number of cells, the second cell to be balanced is charged until the third voltage of the second cell to be balanced is raised to the current average voltage of the individual cells, and then the charging of the second cell to be balanced is stopped; or, the other individual cells are discharged until the third voltage of the second cell to be balanced is raised to the current average voltage of the individual cells, and then the discharge of the other individual cells is stopped.

[0113] In this example, when the third arrangement of the second cell to be balanced is in the last 6 (i.e., in the last 20%), it means that the second cell to be balanced needs to be supplemented or other individual cells need to be discharged, so that the second cell to be balanced is at the average voltage of the individual cells.

[0114] In this embodiment, the execution order of steps S101-S104 and steps S201-S207 can be either to execute steps S101-S104 first and then execute steps S201-S207, or to execute steps S201-S207 first and then execute steps S101-S104, or to execute steps S101-S104 and S201-S207 simultaneously. This application does not limit this.

[0115] Based on the same technical concept, this application also provides a cell balancing device, such as... Figure 3 As shown, the device includes:

[0116] The first acquisition module 301 is used to acquire the first voltage of each individual cell in the power battery when the power battery is in each state of the target state, and to sort the individual cells in order of the first voltage from high to low to obtain the first arrangement order of each individual cell in the target state; the target state includes charging state, static state, and discharging state.

[0117] The first selection module 302 is used to select the first first preset number of individual cells from all the individual cells according to the first arrangement order of each individual cell in the current state, and to use the first arrangement order of each individual cell in the current state to label the selected individual cells once.

[0118] The statistics module 303 is used to count the number of times each individual cell is marked. When the number of times an individual cell is marked is greater than a preset number, the individual cell is identified as the first cell to be balanced. The preset number is determined by the number of states in the target state. The preset number is less than or equal to the number of states in the target state.

[0119] The first equalization module 304 is used to perform discharge equalization on the first cell to be equalized, and to stop the discharge equalization of the first cell to be equalized when the preset discharge equalization conditions are met.

[0120] Optionally, when the first acquisition module 301 is used to acquire the first voltage of each individual cell in the power battery for each state in the target state, and to sort the individual cells according to the first voltage from high to low to obtain the first arrangement order of each individual cell in that state, it is specifically used for:

[0121] Based on the equalization time interval of the power battery, determine whether the current equalization cycle has been reached at the current moment;

[0122] When the current time reaches the current equilibrium cycle, for each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state.

[0123] Optionally, when the first equalization module 304 is used to perform discharge equalization on the first cell to be equalized, and stops the discharge equalization of the first cell to be equalized when a preset discharge equalization condition is reached, it is specifically used for:

[0124] During the charging process of the power battery, each of the first cells to be balanced is discharged, and the current second voltage of each individual cell is detected in real time during the discharge process of the first cells to be balanced.

[0125] The individual battery cells are sorted according to the second voltage from high to low to obtain a second arrangement order for each individual battery cell;

[0126] Determine whether the second arrangement order of the first cell to be balanced is within the first preset number. If the second arrangement order of the first cell to be balanced is not within the first preset number, stop the discharge balancing of the first cell to be balanced.

[0127] Optionally, the device further includes:

[0128] The second acquisition module is used to acquire the battery temperature and the external ambient temperature of the power battery during use.

[0129] The correction module is used to correct the initial temperature field model of the power battery based on the battery temperature and the external ambient temperature to obtain the corrected temperature field model; wherein the initial temperature field model is determined before the power battery leaves the factory.

[0130] The second selection module is used to select, based on the temperature field model, individual cells whose temperatures are in the top second preset number from all the individual cells in the power battery in descending order of individual cell temperature, so as to use the selected individual cells as candidate cells to be balanced.

[0131] The calculation module is used to calculate the difference between the capacity of each individual cell and the capacity of each other individual cell for each individual cell, so as to obtain the capacity difference between the individual cell and each other individual cell.

[0132] The first determining module is used to determine the single cell as the second cell to be balanced when the single cell is the candidate cell to be balanced, if at least one capacity difference among the corresponding capacity differences of the single cell is greater than a first value; wherein, the first value is equal to the product of the first percentage value and the nominal capacity of the single cell;

[0133] The second determining module is used to determine the single cell as the second cell to be balanced when the single cell is not one of the candidate cells to be balanced, if at least one of the capacity differences corresponding to the single cell is greater than a second value; wherein the second value is equal to the product of the second percentage value and the nominal capacity of the single cell; the second percentage value is greater than the first percentage value.

[0134] The second balancing module is used to perform cell balancing on the second cell to be balanced.

[0135] Optionally, when the second equalization module is used to perform cell equalization on the second cell to be equalized, it is specifically used for:

[0136] During the charging process, the third voltage of each individual cell is detected, and the individual cells are sorted in descending order of the third voltage to obtain the third arrangement order of each individual cell.

[0137] For each of the second cells to be balanced, when the third arrangement order of the second cells to be balanced is in the first third preset number, the second cells to be balanced are discharged and balanced until the third voltage of the second cells to be balanced is reduced to the current average voltage of the individual cells, and then the discharge and equalization of the second cells to be balanced is stopped.

[0138] When the third arrangement of the second cell to be balanced is the third preset number of cells, the second cell to be balanced is charged until its third voltage reaches the current average voltage of the individual cell, at which point the charging of the second cell to be balanced stops; or, the other individual cells are discharged until their third voltage reaches the current average voltage of the individual cell, at which point the discharge of the other individual cells stops.

[0139] Figure 4 A schematic diagram of an electronic device provided in this application embodiment includes: a processor 401, a memory 402, and a bus 403. The memory 402 stores machine-readable instructions executable by the processor 401. When the electronic device runs the above-described information processing method, the processor 401 and the memory 402 communicate through the bus 403. The processor 401 executes the machine-readable instructions to perform the steps of the method described in Embodiment 1.

[0140] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps described in Embodiment 1.

[0141] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, electronic devices, and computer-readable storage media described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0142] In the several embodiments provided in this application, it should be understood that the disclosed methods, apparatuses, electronic devices, and computer-readable storage media can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or modules may be electrical, mechanical, or other forms.

[0143] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0144] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0145] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0146] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

Claims

1. A cell balancing method, characterized in that, include: For each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state; the target state includes charging state, static state, and discharging state; Based on the first arrangement order of each individual cell in this state, select the first preset number of individual cells from all the individual cells, and use the first arrangement order of each individual cell in this state to label the selected individual cells once. For each individual battery cell, the number of times the individual battery cell is marked is counted. When the number of times the individual battery cell is marked is greater than a preset number, the individual battery cell is identified as the first battery cell to be balanced. The preset number is determined by the number of states in the target state. The preset number is less than or equal to the number of states in the target state. Discharge equalization is performed on the first cell to be equalized. When the preset discharge equalization condition is reached, the discharge equalization of the first cell to be equalized is stopped. The method further includes: During use, the battery temperature and the external ambient temperature of the power battery are collected. Based on the battery temperature and the external ambient temperature of the power battery, the initial temperature field model of the power battery is corrected to obtain the corrected temperature field model; wherein, the initial temperature field model is determined before the power battery leaves the factory. Based on the temperature field model, in order of the individual cell temperature from high to low, select the individual cells with the highest and second-most preset temperatures from all the individual cells in the power battery, and use the selected individual cells as candidate cells to be equalized. For each individual battery cell, the difference between the capacity of that individual battery cell and the capacity of each other individual battery cell is calculated to obtain the capacity difference between that individual battery cell and each other individual battery cell. When the single cell is the candidate cell to be balanced, if at least one of the capacity differences corresponding to the single cell is greater than the first value, then the single cell is determined as the second cell to be balanced; wherein, the first value is equal to the product of the first percentage value and the nominal capacity of the single cell; When the individual cell is not one of the candidate cells to be balanced, if at least one of the capacity differences corresponding to the individual cell is greater than the second value, then the individual cell is determined as the second cell to be balanced; wherein, the second value is equal to the product of the second percentage value and the nominal capacity of the individual cell; the second percentage value is greater than the first percentage value. Cell balancing is performed on the second cell to be balanced.

2. The method according to claim 1, characterized in that, For each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted according to the first voltage from high to low to obtain the first arrangement order of each individual cell in that state, including: Based on the equalization time interval of the power battery, determine whether the current equalization cycle has been reached at the current moment; When the current time reaches the current equilibrium cycle, for each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state.

3. The method according to claim 1, characterized in that, The step of performing discharge equalization on the first cell to be equalized, and stopping the discharge equalization of the first cell to be equalized when a preset discharge equalization condition is reached, includes: During the charging process of the power battery, each of the first cells to be balanced is discharged, and the current second voltage of each individual cell is detected in real time during the discharge process of the first cells to be balanced. The individual battery cells are sorted according to the second voltage from high to low to obtain a second arrangement order for each individual battery cell; Determine whether the second arrangement order of the first cell to be balanced is within the first preset number. If the second arrangement order of the first cell to be balanced is not within the first preset number, stop the discharge balancing of the first cell to be balanced.

4. The method according to claim 1, characterized in that, The cell balancing process for the second cell to be balanced includes: During the charging process, the third voltage of each individual cell is detected, and the individual cells are sorted in descending order of the third voltage to obtain the third arrangement order of each individual cell. For each of the second cells to be balanced, when the third arrangement order of the second cells to be balanced is in the first third preset number, the second cells to be balanced are discharged and balanced until the third voltage of the second cells to be balanced is reduced to the current average voltage of the individual cells, and then the discharge and equalization of the second cells to be balanced is stopped. When the third arrangement of the second cell to be balanced is the third preset number of cells, the second cell to be balanced is charged until its third voltage reaches the current average voltage of the individual cell, at which point the charging of the second cell to be balanced stops; or, the other individual cells are discharged until their third voltage reaches the current average voltage of the individual cell, at which point the discharge of the other individual cells stops.

5. A cell balancing device, characterized in that, include: The first acquisition module is used to acquire the first voltage of each individual cell in the power battery for each state in the target state. When the power battery is in the target state, the individual cells are sorted in order of the first voltage from high to low to obtain the first arrangement order of each individual cell in the target state. The target state includes charging state, static state, and discharging state. The first selection module is used to select the first preset number of individual cells from all the individual cells according to the first arrangement order of each individual cell in the current state, and to use the first arrangement order of each individual cell in the current state to label the selected individual cells once. The statistics module is used to count the number of times each individual battery cell is marked. When the number of times an individual battery cell is marked is greater than a preset number, the individual battery cell is identified as the first battery cell to be balanced. The preset number is determined by the number of states in the target state. The preset number is less than or equal to the number of states in the target state. The first equalization module is used to perform discharge equalization on the first cell to be equalized. When the preset discharge equalization condition is reached, the discharge equalization of the first cell to be equalized is stopped. The device further includes: The second acquisition module is used to acquire the battery temperature and the external ambient temperature of the power battery during use. The correction module is used to correct the initial temperature field model of the power battery based on the battery temperature and the external ambient temperature to obtain the corrected temperature field model; wherein the initial temperature field model is determined before the power battery leaves the factory. The second selection module is used to select, based on the temperature field model, individual cells whose temperatures are in the top second preset number from all the individual cells in the power battery in descending order of individual cell temperature, so as to use the selected individual cells as candidate cells to be balanced. The calculation module is used to calculate the difference between the capacity of each individual cell and the capacity of each other individual cell for each individual cell, so as to obtain the capacity difference between the individual cell and each other individual cell. The first determining module is used to determine the single cell as the second cell to be balanced when the single cell is the candidate cell to be balanced, if at least one capacity difference among the corresponding capacity differences of the single cell is greater than a first value; wherein, the first value is equal to the product of the first percentage value and the nominal capacity of the single cell; The second determining module is used to determine the single cell as the second cell to be balanced when the single cell is not one of the candidate cells to be balanced, if at least one of the capacity differences corresponding to the single cell is greater than a second value; wherein the second value is equal to the product of the second percentage value and the nominal capacity of the single cell; the second percentage value is greater than the first percentage value. The second balancing module is used to perform cell balancing on the second cell to be balanced.

6. The apparatus according to claim 5, characterized in that, The first acquisition module, when used for each state in the target state, to acquire the first voltage of each individual cell in the power battery when the power battery is in that state, and to sort the individual cells according to the first voltage from high to low, to obtain the first arrangement order of each individual cell in that state, is specifically used for: Based on the equalization time interval of the power battery, determine whether the current equalization cycle has been reached at the current moment; When the current time reaches the current equilibrium cycle, for each state in the target state, when the power battery is in that state, the first voltage of each individual cell in the power battery is collected, and the individual cells are sorted in order from high to low according to the first voltage to obtain the first arrangement order of each individual cell in that state.

7. The apparatus according to claim 5, characterized in that, The first equalization module, when used to perform discharge equalization on the first cell to be equalized, and when stopping the discharge equalization of the first cell to be equalized when a preset discharge equalization condition is reached, is specifically used for: During the charging process of the power battery, each of the first cells to be balanced is discharged, and the current second voltage of each individual cell is detected in real time during the discharge process of the first cells to be balanced. The individual battery cells are sorted according to the second voltage from high to low to obtain a second arrangement order for each individual battery cell; Determine whether the second arrangement order of the first cell to be balanced is within the first preset number. If the second arrangement order of the first cell to be balanced is not within the first preset number, stop the discharge balancing of the first cell to be balanced.

8. An electronic device, characterized in that, include: The device includes a processor, a memory, and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is in operation, the processor communicates with the memory via the bus, and the machine-readable instructions, when executed by the processor, perform the steps of the method as described in any one of claims 1 to 4.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the method as described in any one of claims 1 to 4.

Images