Method, apparatus and device for controlling battery cell of battery pack, and storage medium

Abstract

Disclosed in the embodiments of the present application are a method, apparatus and device for controlling a battery cell of a battery pack, and a storage medium. The method comprises: acquiring a battery pack state of a battery pack; when the total voltage of the battery pack meets a state requirement voltage corresponding to the battery pack state, determining a target battery cell from among a plurality of battery cells to be selected that are located in a main loop of the battery pack; and when the target battery cell meets a cut-off voltage corresponding to the battery pack state, exiting the target battery cell from the main loop by means of an equalization circuit where the target battery cell is located.

Description

A battery cell control method, device, equipment and storage medium for a battery pack Technical Field

[0001] The present application relates to the technical field of battery packs, and in particular to a method, device, equipment and storage medium for controlling battery cells of a battery pack. Background Art

[0002] Currently, electric vehicle battery packs combine multiple cells in series or parallel to meet the vehicle's power needs. Due to limitations in production and testing processes, cell voltages cannot be consistent. Large cell voltage differences can prevent some cells from fully charging or discharging, leading to insufficient battery life.

[0003] Currently, active and passive balancing are commonly used to address inconsistent cell voltages. Passive balancing uses resistor discharge, but this solution takes a long time and can easily cause controller board overheating. Active balancing switches each cell's positive and negative terminals on and off. This solution requires designing a switch matrix, resulting in a complex and costly structure and frequent switching of the balancing circuit. Summary of the Invention

[0004] In view of this, embodiments of the present application provide at least a method, device, equipment, and storage medium for controlling cells of a battery pack.

[0005] The technical solution of the embodiment of the present application is implemented as follows:

[0006] On the one hand, an embodiment of the present application provides a battery cell control method for a battery pack, the method comprising: obtaining the battery pack status of the battery pack; determining a target battery cell among multiple candidate battery cells located in the main circuit of the battery pack when the total voltage of the battery pack meets the status requirement voltage corresponding to the battery pack status; and withdrawing the target battery cell from the main circuit through the balancing circuit where the target battery cell is located when the target battery cell meets the cut-off voltage corresponding to the battery pack status.

[0007] In some embodiments, the main circuit includes a balancing circuit corresponding to each of the multiple battery cells; the balancing circuit includes a first branch and a second branch connected in parallel; wherein, when the first branch is turned on and the second branch is turned off, the battery cells located in the first branch are in the main circuit; when the second branch is turned on and the first branch is turned off, the battery cells located in the first branch are not in the main circuit.

[0008] In some embodiments, the balancing circuit further includes a third branch connected in parallel with the first branch and the second branch, the second branch has no resistance, and the third branch has resistance; the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located, including: switching the third branch to an on state and switching the first branch to an off state; switching the second branch to an on state and switching the third branch to an off state.

[0009] In some embodiments, the battery pack state includes a discharge state; when the total voltage of the battery pack meets the state requirement voltage corresponding to the battery pack state, determining the target battery cell among the multiple battery cells to be selected in the main circuit of the battery pack includes: when the total voltage of the battery pack meets the discharge cut-off voltage corresponding to the discharge state, determining the target discharge battery cell among the multiple battery cells to be selected in the main circuit of the battery pack; the target discharge battery cell is the battery cell with the lowest voltage among the multiple battery cells to be selected; accordingly, when the target battery cell meets the cut-off voltage corresponding to the battery pack state, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located, including: when the voltage of the target discharge battery cell is less than the full discharge cut-off voltage, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located.

[0010] In some embodiments, the battery pack status includes a charging status; when the total voltage of the battery pack meets the status requirement voltage corresponding to the battery pack status, a target battery cell is determined among multiple battery cells to be selected in the main circuit of the battery pack, including: when the total voltage of the battery pack meets the charging cut-off voltage corresponding to the charging status, a target charging battery cell is determined among multiple battery cells to be selected in the main circuit of the battery pack; the target charging battery cell is the battery cell with the largest voltage among the multiple battery cells to be selected; accordingly, when the target battery cell meets the cut-off voltage corresponding to the battery pack status, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located, including: when the voltage of the target charging battery cell is greater than or equal to the full charge cut-off voltage, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located.

[0011] In some embodiments, the charging state includes a first charging state and a second charging state, the charging speed of the first charging state is lower than the charging speed of the second charging state; the charging cut-off voltage of the first charging state is lower than the charging cut-off voltage of the second charging state.

[0012] In some embodiments, in response to withdrawing the target battery cell from the main circuit, the total voltage of the battery pack continues to be monitored, and when the total voltage of the battery pack meets the required voltage corresponding to the battery pack status, the target battery cell is determined from multiple candidate battery cells located in the main circuit of the battery pack; when the target battery cell meets the cutoff voltage corresponding to the battery pack status, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located; until the total voltage of the battery pack no longer meets the required voltage corresponding to the battery pack status.

[0013] On the other hand, an embodiment of the present application provides a cell control device for a battery pack, comprising:

[0014] an acquisition module, configured to acquire a battery pack status of the battery pack;

[0015] a determination module configured to determine a target battery cell from a plurality of candidate battery cells located in a main circuit of the battery pack when the total voltage of the battery pack meets a state requirement voltage corresponding to the battery pack state;

[0016] The adjustment module is configured to, when the target cell meets the cut-off voltage corresponding to the battery pack state, remove the target cell from the main circuit through the balancing circuit where the target cell is located.

[0017] On the other hand, an embodiment of the present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, it implements some or all of the steps in the above method.

[0018] On the other hand, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which implements some or all of the steps in the above method when executed by a processor.

[0019] The battery cell control method of the battery pack provided in the embodiment of the present application obtains the battery pack status of the battery pack, and determines the target battery cell among the multiple candidate battery cells located in the main circuit of the battery pack when the total voltage of the battery pack meets the state requirement voltage corresponding to the battery pack status; when the target battery cell meets the cut-off voltage corresponding to the battery pack status, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located. In the subsequent processing, the total voltage of the battery pack is continued to be detected, and the above operation is repeated until the total voltage of the battery pack does not meet the state requirement voltage corresponding to the battery pack status. In this way, it is possible to ensure that the vast majority of battery cells are in a fully charged or fully discharged state, and avoid the problem of the battery pack power not being able to be released due to the bucket effect, effectively solving the problem of all battery cells not being able to be fully charged or fully discharged due to the inconsistency of the battery pack cells, thereby improving the charge and discharge capacity of the entire battery pack and the cruising range of the vehicle-mounted battery pack.

[0020] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit the technical solutions of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and, together with the specification, are used to illustrate the technical solutions of the present application.

[0022] FIG1 is a schematic diagram of a first implementation flow of a method for controlling a cell of a battery pack provided in an embodiment of the present application;

[0023] FIG2 is a first circuit diagram of a method for controlling a cell of a battery pack according to an embodiment of the present application;

[0024] FIG3 is a second circuit diagram of a method for controlling a cell of a battery pack provided in an embodiment of the present application;

[0025] FIG4 is a third circuit diagram of a method for controlling a cell of a battery pack provided in an embodiment of the present application;

[0026] FIG5 is a fourth circuit diagram of a method for controlling a cell of a battery pack provided in an embodiment of the present application;

[0027] FIG6 is a second schematic diagram of an implementation flow of a cell control method for a battery pack provided in an embodiment of the present application;

[0028] FIG7 is a third schematic diagram of an implementation flow of a cell control method for a battery pack provided in an embodiment of the present application;

[0029] FIG8 is a fourth schematic diagram of a flow chart of a method for controlling a cell of a battery pack according to an embodiment of the present application;

[0030] FIG9 is a schematic diagram of the composition structure of a cell control device of a battery pack provided in an embodiment of the present application;

[0031] FIG10 is a schematic diagram of a hardware entity of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions of this application are further elaborated in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] In the following description, references to "some embodiments" describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict. The terms "first / second / third" are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understood that the specific order or sequence of "first / second / third" may be interchanged where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing this application only and are not intended to limit this application.

[0035] The present application provides a method for controlling battery cells in a battery pack, which can be executed by a processor of a computer device. The computer device may include a server, laptop computer, tablet computer, desktop computer, smart TV, set-top box, mobile device (e.g., mobile phone, portable video player, personal digital assistant, dedicated messaging device, portable gaming device), or other device with data processing capabilities.

[0036] FIG1 is a schematic diagram of a first implementation flow of a method for controlling a cell of a battery pack provided in an embodiment of the present application. As shown in FIG1 , the method includes the following steps S101 to S103:

[0037] Step S101: Acquire the battery pack status of the battery pack.

[0038] In the embodiment of the present application, the battery cell control method is mainly applied to electric vehicles with battery packs. The battery packs of electric vehicles are combined by connecting multiple battery cells in series / parallel to meet the power demand of the entire vehicle.

[0039] In the embodiment of the present application, the battery pack status refers to the working status of the battery pack. In some scenarios, the battery pack status includes a charging state and a discharging state.

[0040] In some embodiments, the battery pack status of the battery pack can be obtained in the following manner: By detecting the direction of the current flowing through the battery pack, it can be determined whether the battery pack is in a charging state or a discharging state. When the current flows from the external power source to the battery pack, it indicates that the battery pack is in a charging state. When the current flows from the battery pack to the vehicle's electrical accessories, it indicates that the battery pack is in a discharging state.

[0041] In some embodiments, the battery pack status of the battery pack can also be obtained in the following manner: by connecting to a battery management system (BMS), information such as the battery pack status, remaining charge, and charge / discharge power of the battery pack can be obtained. The BMS typically monitors parameters such as current, voltage, and temperature, and determines whether the battery pack status is in a charging state or a discharging state based on these parameters.

[0042] It is understandable that the method for obtaining the battery pack status of the battery pack is not limited thereto and is not limited in the embodiments of the present application.

[0043] Step S102 : determining a target battery cell from a plurality of candidate battery cells located in a main circuit of the battery pack when the total voltage of the battery pack meets a state requirement voltage corresponding to the battery pack state.

[0044] In the embodiment of the present application, the main circuit represents the main circuit path of the battery pack for providing electrical energy, and the main circuit is mainly responsible for charging and discharging the battery pack. Since the battery pack state represents the working state of the battery pack, accordingly, the state requirement voltage corresponding to the battery pack state represents the conditional working voltage of the battery pack in this working state. Exemplarily, when the battery pack state is in a discharge state, the state requirement voltage is the discharge cut-off voltage of the battery pack in the discharge state; when the battery pack is in a charging state, the state requirement voltage is the charge cut-off voltage of the battery pack in the charging state. The target cell represents the cell selected from the main circuit of the battery pack for charging or discharging in the battery pack state. Exemplarily, when the battery pack state is in a discharge state, the target cell is the target discharge cell; when the battery pack state is in a charging state, the target cell is the target charging cell.

[0045] In an embodiment of the present application, when the battery pack is in a discharging state, the voltage required for this state is the discharge cutoff voltage of the battery pack in the discharging state. When the total voltage of the battery pack is greater than the discharge cutoff voltage, a target discharge cell is determined from multiple cells to be selected in the main circuit of the battery pack. When the battery pack is in a charging state, the voltage required for this state is the charge cutoff voltage of the battery pack in the charging state. When the total voltage of the battery pack is greater than the charge cutoff voltage, a target charge cell is determined from multiple cells to be selected in the main circuit of the battery pack.

[0046] It is understandable that the number of cells in the main circuit of the battery pack may be more or less than 4, and this embodiment of the present application does not limit this.

[0047] In an embodiment of the present application, based on the obtained battery pack state, the total voltage of the battery pack is compared with the state requirement voltage corresponding to the battery pack state. When the total voltage of the battery pack is less than the state requirement voltage corresponding to the battery pack state, it indicates that the single cell does not meet the conditional operating voltage of the working state. Since a single cell is cut out, the total voltage of the battery pack is less than the state requirement voltage corresponding to the battery pack state, which causes the battery pack to be unable to continue discharging or discharge, and the current state is maintained without processing; when the total voltage of the battery pack is greater than the state requirement voltage corresponding to the battery pack state, it indicates that the battery pack can work normally. When the battery pack can work normally, the target cell is determined from the multiple cells to be selected in the main circuit of the battery pack. For example, when the battery pack is in a discharging state, when the total voltage of the battery pack is less than the discharge cut-off voltage, the current state is maintained without processing; when the total voltage of the battery pack is greater than the discharge cut-off voltage, the target discharge cell is determined from the multiple cells to be selected in the main circuit of the battery pack. When the battery pack is in a charging state, if the total voltage of the battery pack is less than the charging cut-off voltage, the current state is maintained without processing; when the total voltage of the battery pack is greater than the charging cut-off voltage, a target charging cell is determined from multiple candidate cells in the main circuit of the battery pack.

[0048] In an embodiment of the present application, by determining the target battery cell among multiple candidate battery cells located in the main circuit of the battery pack when the total voltage of the battery pack meets the state requirement voltage corresponding to the battery pack state, it can be ensured that the battery pack continues to operate normally and meets the performance requirements of the battery pack.

[0049] Step S103 : When the target cell meets the cut-off voltage corresponding to the battery pack state, the target cell is removed from the main circuit through the balancing circuit where the target cell is located.

[0050] In the embodiment of the present application, since the battery pack state represents the working state of the battery pack, accordingly, the cut-off voltage corresponding to the battery pack state represents the termination voltage of the battery pack in the working state. For example, when the battery pack state is in the discharge state, the cut-off voltage is the full discharge cut-off voltage of the battery pack in the discharge state. The full discharge cut-off voltage represents the lowest voltage reached by the battery pack in the discharge state. The battery pack is considered to be exhausted and cannot provide power output; when the battery pack is in the charging state, the cut-off voltage is the full charge cut-off voltage of the battery pack in the charging state. The full charge cut-off voltage represents the highest voltage reached by the battery pack in the charging state. The battery pack is considered to be fully charged and cannot be charged anymore. The balancing circuit is a circuit used to balance the inconsistent voltages between multiple battery cells. By controlling the flow of current, the voltage of each battery cell in the battery pack is kept consistent. For example, the high voltage of the battery cell with excessive voltage is adjusted by resistive discharge to keep the voltage between the battery cells consistent.

[0051] In the embodiment of the present application, when the battery pack is in a discharging state, the cut-off voltage is the full-discharge cut-off voltage of the battery pack in the discharging state. When the target discharging cell reaches the full-discharge cut-off voltage, it indicates that the discharging cell can no longer be discharged. Through the balancing circuit where the target discharging cell is located, the target discharging cell is withdrawn from the main circuit of the battery pack, allowing the cells that have not been fully discharged to continue discharging. When the battery pack is in a charging state, the cut-off voltage is the full-charge cut-off voltage of the battery pack in the discharging state. When the target charging cell reaches the full-charge cut-off voltage, it indicates that the charging cell has been fully charged. Through the balancing circuit where the target charging cell is located, the target charging cell is withdrawn from the main circuit of the battery pack.

[0052] In an embodiment of the present application, when the target cell meets the cut-off voltage corresponding to the battery pack state, the target cell is withdrawn from the main circuit of the battery pack through the balancing circuit where the target cell is located. During charging, the fully charged cells can be withdrawn from the main circuit of the battery pack, allowing the cells that are not fully charged to continue charging, thereby ensuring that the vast majority of cells are in a fully charged state as much as possible; during discharging, the fully discharged cells can be withdrawn from the main circuit of the battery pack to avoid the inability to release the battery pack power due to the bucket effect.

[0053] Based on the above embodiment, by determining the target cell among the multiple cells to be selected in the main circuit of the battery pack when the total voltage of the battery pack meets the required voltage corresponding to the state of the battery pack, it is possible to ensure that the battery pack continues to operate normally and meets the performance requirements of the battery pack; at the same time, when the target cell meets the cut-off voltage corresponding to the state of the battery pack, the target cell is withdrawn from the main circuit of the battery pack through the balancing circuit where the target cell is located. When charging, the fully charged cells can be withdrawn from the main circuit of the battery pack, allowing the cells that are not fully charged to continue charging, so as to ensure that the vast majority of cells are in a fully charged state as much as possible; when discharging, the fully discharged cells can be withdrawn from the main circuit of the battery pack to avoid the inability to release the battery pack power due to the bucket effect. In addition, the present application can effectively solve the problem that all cells cannot be fully charged or fully discharged due to inconsistent battery pack cells, thereby improving the charge and discharge capacity of the entire battery pack and the cruising range of the vehicle-mounted battery pack.

[0054] In some embodiments, the main circuit includes a balancing circuit corresponding to each of the multiple battery cells; the balancing circuit includes a first branch and a second branch connected in parallel; wherein, when the first branch is turned on and the second branch is turned off, the battery cells located in the first branch are in the main circuit; when the second branch is turned on and the first branch is turned off, the battery cells located in the first branch are not in the main circuit.

[0055] In some embodiments, the main circuit of the battery pack includes a plurality of battery cells and a balancing circuit corresponding to each of the plurality of battery cells. The balancing circuit has two branches, namely a first branch and a second branch.

[0056] In some embodiments, in an initial state, the first branch is in an on state and the second branch is in an off state. The switching process of the balancing circuit switching the first branch to the second branch includes:

[0057] Step 1: Switch the first branch to the on state and the second branch to the off state;

[0058] Step 2: Switch the second branch to the on state and switch the first branch to the off state.

[0059] In some embodiments, in an initial state, the target cell is located in the main circuit of the battery pack. The first branch is switched to an on state and the second branch is switched to an off state, at which point the first branch is in the main circuit. The second branch is switched to an on state and the first branch is switched to an off state, at which point the second branch is in the main circuit.

[0060] Refer to Figure 2, which is a schematic diagram of a circuit implementing a battery cell control method for a battery pack according to an embodiment of the present application. The balancing circuit includes a first branch 1 and a second branch 2. These two branches are connected in parallel. In some scenarios, the first branch 1 includes at least components such as a battery cell and a switch, while the second branch 2 includes at least components such as a switch.

[0061] Refer to Figure 3, which is a second circuit diagram of an implementation of a battery cell control method for a battery pack provided in an embodiment of the present application. The circuit includes multiple battery cells and a balancing circuit corresponding to each of the multiple battery cells, wherein the balancing circuit includes a first branch and a second branch. In some scenarios, the branch where the battery cell Ci is located is the first branch, and the branch where the switch Si3 is located is the second branch. In some scenarios, the first branch includes at least components such as the battery cell Ci and the switch Si1, and the second branch includes at least components such as the switch Si3.

[0062] It is understandable that the representation of the circuit's balancing loop is not limited to this, and is not limited in the embodiments of the present application.

[0063] In some embodiments, the balancing circuit further includes a third branch connected in parallel with the first branch and the second branch, the second branch having no resistance, and the third branch having a resistance. Removing the target cell from the main circuit through the balancing circuit where the target cell is located includes: switching the third branch to an on state and switching the first branch to an off state; and switching the second branch to an on state and switching the third branch to an off state.

[0064] In some embodiments, the balancing circuit includes a first branch and a second branch, and further includes a third branch connected in parallel with the first branch and the second branch, wherein the second branch has no resistor and the third branch has a resistor.

[0065] In some embodiments, in the initial state, the first branch is in the on state, and the second branch and the third branch are both in the off state. The process of removing the target cell from the main circuit of the battery pack through the balancing circuit where the target cell is located includes:

[0066] Step 1: Switch the third branch from the disconnected state to the conductive state, and switch the first branch from the conductive state to the disconnected state;

[0067] Step 2: Switch the second branch from the disconnected state to the conductive state, and switch the third branch from the conductive state to the disconnected state.

[0068] In some embodiments, initially, the target cell is located in the main circuit of the battery pack. First, the third branch is switched on and the first branch is switched off. At this point, the third branch is in the main circuit, and the target cell is in the first branch. This removes the target cell from the main circuit. Next, the second branch is switched on and the third branch is switched off to prevent overheating of the controller board due to resistor discharge.

[0069] Refer to Figure 4, which is a third circuit diagram of a battery cell control method for a battery pack provided in an embodiment of the present application. The balancing circuit includes a first branch 1, a second branch 2, and a third branch 3. The three branches are connected in parallel. In some scenarios, the first branch 1 includes at least components such as a battery cell and a switch, the second branch 2 includes at least components such as a switch, and the third branch 3 includes at least components such as a resistor and a switch.

[0070] Refer to Figure 5, which is a fourth circuit diagram of an implementation of a battery cell control method for a battery pack provided in an embodiment of the present application. The circuit includes multiple battery cells and a balancing circuit corresponding to each of the multiple battery cells, wherein the balancing circuit includes a first branch, a second branch, and a third branch. In some scenarios, the branch where the battery cell Ci and the switch Si1 are located is the first branch, which is the main circuit of the battery pack, the branch where the switch Si3 is located is the second branch, and the branch where the resistor Ri and the switch Si2 are located is the third branch.

[0071] In some embodiments, the target cell is removed from the main circuit via the balancing circuit in which the target cell is located. In some scenarios, the target cell can be removed from the main circuit of the battery pack by first closing the Si2 switch, then opening the Si1 switch, then closing the Si3 switch, and finally opening the Si2 switch.

[0072] It is understandable that the method for the target battery cell of the balancing circuit to exit the main circuit is not limited to this, and is not limited in the embodiments of the present application.

[0073] In the embodiment of the present application, the target cell is removed from the main circuit of the battery pack through the balancing circuit where the target cell is located. In this way, other cells can operate in the main circuit to ensure that the voltages of as many cells as possible remain consistent.

[0074] Figure 6 is a second schematic flow diagram illustrating an implementation of a battery pack cell control method provided in an embodiment of the present application. This method can be executed by a processor of a computer device. Based on Figure 1 , the battery pack status includes a discharge state; step S102 can be updated to S601, and step S103 can be updated to S602. The steps shown in Figure 6 will be described below.

[0075] Step S601: When the total voltage of the battery pack satisfies the discharge cut-off voltage corresponding to the discharge state, a target discharge cell is determined among multiple cells to be selected in the main circuit of the battery pack; the target discharge cell is the cell with the lowest voltage among the multiple cells to be selected.

[0076] In an embodiment of the present application, when the battery pack is in a discharge state, the state requires the voltage to be the discharge cut-off voltage of the battery pack in the discharge state. When the total voltage of the battery pack meets the discharge cut-off voltage corresponding to the discharge state, it indicates that the battery pack can work normally. When the battery pack can work normally, the target cell is determined among the multiple cells to be selected in the main circuit of the battery pack. Among them, the target cell is the cell with the lowest voltage among the multiple cells to be selected, because it protects other cells to be selected in the battery pack and prevents these cells from reaching the discharge cut-off voltage too early. In some scenarios, when it is detected that the battery pack is in a discharge state and the total voltage of the battery pack is greater than the discharge cut-off voltage +3V, the cell with the lowest cell voltage in the main circuit is detected.

[0077] In an embodiment of the present application, when the total voltage of the battery pack meets the discharge cut-off voltage corresponding to the discharge state, by determining the candidate cell with the lowest voltage among multiple candidate cells located in the main circuit of the battery pack as the target discharge cell, other candidate cells in the battery pack can be protected to prevent these cells from reaching the discharge cut-off voltage too early, which would cause the entire battery pack to be unable to continue discharging and reduce the service life of the battery pack.

[0078] Step S602: When the target discharge cell voltage is lower than the full-discharge cut-off voltage, the target cell is removed from the main circuit through the balancing circuit where the target cell is located.

[0079] In an embodiment of the present application, when the selected cell with the lowest voltage is determined as the target discharge cell, when the voltage of the target discharge cell is less than the full discharge cut-off voltage, it indicates that the target discharge cell has been completely discharged, and the target discharge cell is exited from the main circuit of the battery pack through the balancing circuit in which the target discharge cell is located. In some scenarios, based on the example of Figure 5, when the lowest cell voltage Ci is less than the full discharge cut-off voltage, the Si2 switch is closed first, then the Si1 switch is opened, then the Si3 switch is closed, and finally the Si2 switch is opened, so that the cell with the lowest cell voltage exits from the main circuit in which the cell is located.

[0080] In this embodiment of the present application, when the cell with the lowest voltage is selected as the target discharge cell, when the voltage of the target discharge cell falls below the full-discharge cutoff voltage, the balancing circuit in which the target discharge cell is located causes the target discharge cell to be removed from the main circuit of the battery pack. This allows the fully discharged cell to be removed from the main circuit, allowing the remaining cells to continue discharging, thus avoiding the inability to discharge the battery pack's charge due to the bucket effect.

[0081] Figure 7 is a third schematic flow diagram of a method for controlling a battery cell in a battery pack according to an embodiment of the present application. This method can be executed by a processor of a computer device. Based on Figure 1 , the battery pack status includes the charging status; step S102 can be updated to S701, and step 103 can be updated to S702. The steps shown in Figure 7 will be described below.

[0082] Step S701: When the total voltage of the battery pack meets the charging cut-off voltage corresponding to the charging state, determine a target charging cell among multiple candidate cells located in the main circuit of the battery pack; the target charging cell is the candidate cell with the highest voltage among the multiple candidate cells.

[0083] In an embodiment of the present application, when the battery pack is in a charging state, the state requires the voltage to be the charging cut-off voltage of the battery pack in the discharging state. When the total voltage of the battery pack meets the charging cut-off voltage corresponding to the discharging state, it indicates that the battery pack can work normally. When the battery pack can work normally, the target cell is determined among the multiple cells to be selected in the main circuit of the battery pack. Among them, the target cell is the cell with the highest voltage among the multiple cells to be selected. The reason is that the charging of the battery pack is controlled by the cell with the highest voltage to be selected, to protect the safety and performance of the entire battery pack, and to prevent the voltage of some cells from being too high, causing overheating. In some scenarios, when it is detected that the battery pack is in a charging state and the total voltage of the battery pack is greater than the charging cut-off voltage, the cell with the highest cell voltage in the main circuit is detected.

[0084] In an embodiment of the present application, when the total voltage of the battery pack meets the charging cut-off voltage corresponding to the charging state, by determining the candidate cell with the highest voltage among multiple candidate cells located in the main circuit of the battery pack as the target charging cell, the safety and performance of the entire battery pack can be protected, and the voltage of some of the cells can be prevented from being too high, exceeding the charging cut-off voltage, which may cause abnormal reactions in the cells, such as overcharging, overheating, and even fire and other dangerous situations, thereby improving the life and safety of the battery pack.

[0085] Step S702: When the target charging cell has a voltage greater than or equal to the full-charge cut-off voltage, the target cell is removed from the main circuit through the balancing circuit where the target cell is located.

[0086] In an embodiment of the present application, when the selected cell with the highest voltage is determined as the target charging cell, when the voltage of the target charging cell is greater than or equal to the full charge cut-off voltage, it indicates that the target charging cell is fully charged, and the target charging cell is removed from the main circuit of the battery pack through the balancing circuit in which the target charging cell is located. In some scenarios, based on the example of Figure 5, when the highest cell voltage Ci is greater than or equal to the full charge cut-off voltage, the Si2 switch is closed first, then the Si1 switch is opened, then the Si3 switch is closed, and finally the Si2 switch is opened, so that the cell with the highest cell voltage is removed from the first branch where the cell is located.

[0087] In the embodiment of the present application, when the selected cell with the highest voltage is selected as the target cell, when the voltage of the target cell is greater than or equal to the full-charge cut-off voltage, the balancing circuit in which the target cell is located causes the target cell to be removed from the main circuit of the battery pack. This allows the fully charged cell to be removed from the main circuit, allowing the partially charged cells to continue charging, thus ensuring that the majority of cells are fully charged as much as possible.

[0088] In some embodiments, the charging state includes a first charging state and a second charging state, wherein the charging speed of the first charging state is lower than the charging speed of the second charging state, and the charging cut-off voltage of the first charging state is lower than the charging cut-off voltage of the second charging state. In some scenarios, the first charging state is a slow charging state, and the second charging state is a fast charging state. The charging cut-off voltage of the slow charging state is the on-board charger (OBC) operating lower limit voltage of +4V, and the charging cut-off voltage of the fast charging state is the fast charging pile operating lower limit voltage of 200V.

[0089] FIG8 is a fourth flow chart of a method for controlling a cell of a battery pack according to an embodiment of the present application, which can be executed by a processor of a computer device. Based on FIG1 , the method further includes S801 , which will be described in conjunction with the steps shown in FIG8 .

[0090] Step S801, in response to withdrawing the target battery cell from the main circuit, continue to monitor the total voltage of the battery pack, and when the total voltage of the battery pack meets the state requirement voltage corresponding to the battery pack state, determine the target battery cell from the multiple candidate battery cells located in the main circuit of the battery pack; when the target battery cell meets the cut-off voltage corresponding to the battery pack state, withdraw the target battery cell from the main circuit through the balancing circuit where the target battery cell is located; until the total voltage of the battery pack does not meet the state requirement voltage corresponding to the battery pack state.

[0091] In an embodiment of the present application, after the determined target cell exits the main circuit through the balancing circuit, the total voltage of the battery pack continues to be monitored, and the total voltage of the battery pack is compared with the state requirement voltage corresponding to the battery pack state. If the total voltage of the battery pack is still greater than the state requirement voltage corresponding to the battery pack state, it indicates that the battery pack can operate normally. If the battery pack can operate normally, the target cell is determined from the multiple cells to be selected in the main circuit of the battery pack. If the target cell meets the cut-off voltage corresponding to the battery pack state, the target cell is exited from the main circuit of the battery pack through the balancing circuit where the target cell is located until the total voltage of the battery pack no longer meets the state requirement voltage corresponding to the battery pack state.

[0092] In some scenarios, based on the example in Figure 5, the system re-determines whether the total battery pack voltage is greater than the discharge cutoff voltage +3V. If it is still greater than the discharge cutoff voltage +3V, the system continues to determine whether the lowest remaining cell voltage Cj in the main circuit is less than the cell full-discharge cutoff voltage. If the full-discharge cutoff voltage is met, the system first closes switch Sj2, then opens switch Sj1, then closes switch Sj3, and finally opens switch Sj2. The system then proceeds to the next judgment, and the above actions are not terminated until the total battery pack voltage is lower than the discharge cutoff voltage +3V.

[0093] In the embodiment of the present application, in response to the removal of the target cell from the main circuit, the total voltage of the battery pack is continuously monitored, and when the total voltage of the battery pack meets the required voltage corresponding to the state of the battery pack, the target cell is determined from multiple cells to be selected in the main circuit of the battery pack; when the target cell meets the cutoff voltage corresponding to the state of the battery pack, the target cell is removed from the main circuit through the balancing circuit where the target cell is located; until the total voltage of the battery pack no longer meets the required voltage corresponding to the state of the battery pack. In this way, the fully charged / fully discharged cells in the entire main circuit can be removed from the main circuit, allowing the partially charged / fully discharged cells to continue charging / discharging, which can effectively solve the problem of the battery being unable to be fully charged or fully discharged due to cell consistency.

[0094] Based on the foregoing embodiments, an embodiment of the present application provides a cell control device for a battery pack, which includes the various units included and the various modules included in each unit, and can be implemented by a processor in a computer device; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA), etc.

[0095] FIG9 is a schematic diagram of the structure of a cell control device for a battery pack according to an embodiment of the present application. As shown in FIG9 , a cell control device 900 for a battery pack includes: an acquisition module 910 , a determination module 920 , and an adjustment module 930 , wherein:

[0096] The acquisition module 910 is configured to acquire the battery pack status of the battery pack.

[0097] The determination module 920 is configured to determine a target battery cell from a plurality of candidate battery cells located in a main circuit of the battery pack when the total voltage of the battery pack meets the state requirement voltage corresponding to the battery pack state.

[0098] In some embodiments, the battery pack state includes a discharge state; the determination module 920 is further configured to determine a target discharge cell among multiple candidate cells located in the main circuit of the battery pack when the total voltage of the battery pack meets the discharge cut-off voltage corresponding to the discharge state; the target discharge cell is the candidate cell with the lowest voltage among the multiple candidate cells.

[0099] In some embodiments, the battery pack status includes a charging status; the determination module 920 is further configured to determine a target charging cell among multiple candidate cells located in the main circuit of the battery pack when the total voltage of the battery pack meets the charging cut-off voltage corresponding to the charging status; the target charging cell is the candidate cell with the largest voltage among the multiple candidate cells.

[0100] The adjustment module 930 is configured to remove the target cell from the main circuit through the balancing circuit where the target cell is located when the target cell meets the cut-off voltage corresponding to the battery pack state.

[0101] In some embodiments, the main circuit includes a balancing circuit corresponding to each of the plurality of battery cells; the balancing circuit includes a first branch and a second branch connected in parallel; wherein, when the first branch is turned on and the second branch is turned off, the battery cell located in the first branch is in the main circuit;

[0102] When the second branch is turned on and the first branch is turned off, the battery cells located in the first branch are not in the main circuit.

[0103] In some embodiments, the balancing circuit further includes a third branch connected in parallel with the first branch and the second branch, the second branch has no resistance, and the third branch has resistance; the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located.

[0104] In some embodiments, the adjustment module 930 is further configured to switch the third branch to the on state and the first branch to the off state; switch the second branch to the on state and the third branch to the off state.

[0105] In some embodiments, the charging state includes a first charging state and a second charging state, the charging speed of the first charging state is lower than the charging speed of the second charging state; the charging cut-off voltage of the first charging state is lower than the charging cut-off voltage of the second charging state.

[0106] In some embodiments, the adjustment module 930 is further configured to remove the target cell from the main circuit through the balancing circuit where the target cell is located when the voltage of the target discharge cell is lower than the full-discharge cut-off voltage.

[0107] In some embodiments, the adjustment module 930 is further configured to, when the voltage of the target charging cell is greater than or equal to the full charge cut-off voltage, remove the target cell from the main circuit through the balancing circuit where the target cell is located.

[0108] In some embodiments, the adjustment module 930 is further configured to, in response to withdrawing the target battery cell from the main circuit, continue to monitor the total voltage of the battery pack, and determine a target battery cell from a plurality of candidate battery cells located in the main circuit of the battery pack when the total voltage of the battery pack meets the required voltage corresponding to the battery pack status; and when the target battery cell meets the cutoff voltage corresponding to the battery pack status, withdraw the target battery cell from the main circuit through the balancing circuit where the target battery cell is located.

[0109] The description of the above device embodiment is similar to the description of the above method embodiment and has similar beneficial effects as the method embodiment. In some embodiments, the functions or modules included in the device provided in the embodiments of the present application can be used to perform the methods described in the above method embodiments. For technical details not disclosed in the device embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

[0110] It should be noted that in the embodiment of the present application, if the above-mentioned battery cell control method of a battery pack is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk. In this way, the embodiment of the present application is not limited to any specific hardware, software or firmware, or any combination of hardware, software and firmware.

[0111] An embodiment of the present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, some or all of the steps in the above method are implemented.

[0112] The present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements some or all of the steps in the above method. The computer-readable storage medium may be transient or non-transient.

[0113] An embodiment of the present application provides a computer program, including computer-readable code. When the computer-readable code is run in a computer device, a processor in the computer device executes some or all of the steps for implementing the above method.

[0114] An embodiment of the present application provides a computer program product, comprising a non-transitory computer-readable storage medium storing a computer program. When the computer program is read and executed by a computer, the computer program implements some or all of the steps of the above-described method. The computer program product can be implemented in hardware, software, or a combination thereof. In some embodiments, the computer program product is embodied as a computer storage medium. In other embodiments, the computer program product is embodied as a software product, such as a software development kit (SDK).

[0115] It should be noted that the descriptions of the various embodiments above tend to emphasize the differences between the various embodiments, and their similarities or similarities can be referenced to each other. The descriptions of the above device, storage medium, computer program, and computer program product embodiments are similar to the descriptions of the above method embodiments and have similar beneficial effects as the method embodiments. For technical details not disclosed in the embodiments of the device, storage medium, computer program, and computer program product of this application, please refer to the description of the method embodiments of this application for understanding.

[0116] Figure 10 is a schematic diagram of the hardware entity of a computer device provided in an embodiment of the present application. As shown in Figure 10, the hardware entity of the computer device 1000 includes: a processor 1001 and a memory 1002, wherein the memory 1002 stores a computer program that can be run on the processor 1001, and when the processor 1001 executes the program, the steps in the method of any of the above embodiments are implemented.

[0117] The memory 1002 stores computer programs that can be run on the processor. The memory 1002 is configured to store instructions and applications executable by the processor 1001. It can also cache data to be processed or processed by the processor 1001 and various modules in the computer device 1000 (for example, image data, audio data, voice communication data, and video communication data). This can be achieved through flash memory (FLASH) or random access memory (RAM).

[0118] When the processor 1001 executes the program, the steps of the battery cell control method of any of the above embodiments are implemented. The processor 1001 generally controls the overall operation of the computer device 1000.

[0119] An embodiment of the present application provides a computer storage medium, which stores one or more programs. The one or more programs can be executed by one or more processors to implement the steps of a battery cell control method of a battery pack as described in any of the above embodiments.

[0120] It should be noted that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0121] The processor may be at least one of an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a central processing unit (CPU), a controller, a microcontroller, and a microprocessor. It is understood that the electronic device that implements the functions of the processor may also be other electronic devices, and the embodiments of the present application are not specifically limited thereto.

[0122] The above-mentioned computer storage medium / memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory (Flash Memory), a magnetic surface storage device, an optical disc, or a compact disc read-only memory (CD-ROM); it can also be various terminals that include one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc.

[0123] The above is only an implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A method for controlling a battery cell of a battery pack, characterized in that: include: Obtaining a battery pack status of the battery pack; When the total voltage of the battery pack meets the state requirement voltage corresponding to the battery pack state, determining a target battery cell from a plurality of battery cells to be selected in a main circuit of the battery pack; When the target battery cell meets the cut-off voltage corresponding to the battery pack state, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located.

2. The method according to claim 1, characterized in that The main circuit includes a balancing circuit corresponding to each of the plurality of cells; the balancing circuit includes a first branch and a second branch connected in parallel; wherein, When the first branch is turned on and the second branch is turned off, the battery cell located in the first branch is in the main circuit; When the second branch is turned on and the first branch is turned off, the battery cells located in the first branch are not in the main circuit.

3. The method according to claim 2, characterized in that The balancing circuit further includes a third branch connected in parallel with the first branch and the second branch, the second branch has no resistance, and the third branch has resistance; the target battery cell is removed from the main circuit through the balancing circuit where the target battery cell is located, comprising: Switching the third branch to an on state and switching the first branch to an off state; The second branch is switched to an on state, and the third branch is switched to an off state.

4. The method according to any one of claims 1 to 3, characterized in that The battery pack state includes a discharge state; The method of determining a target cell among multiple cells to be selected in the main circuit of the battery pack when the total voltage of the battery pack meets the required voltage of the state corresponding to the battery pack state includes: determining a target discharge cell among multiple cells to be selected in the main circuit of the battery pack when the total voltage of the battery pack meets the discharge cut-off voltage corresponding to the discharge state; the target discharge cell is the cell to be selected with the lowest voltage among the multiple cells to be selected; Correspondingly, when the target battery cell meets the cut-off voltage corresponding to the battery pack state, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located, including: when the voltage of the target discharge battery cell is less than the full discharge cut-off voltage, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located.

5. The method according to any one of claims 1 to 3, characterized in that The battery pack status includes a charging status; The method of determining a target cell among multiple cells to be selected in the main circuit of the battery pack when the total voltage of the battery pack meets the required voltage of the state corresponding to the battery pack state comprises: determining a target charging cell among multiple cells to be selected in the main circuit of the battery pack when the total voltage of the battery pack meets the charging cut-off voltage corresponding to the charging state; the target charging cell is a cell to be selected with the largest voltage among the multiple cells to be selected; Correspondingly, when the target battery cell meets the cut-off voltage corresponding to the battery pack state, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located, including: when the voltage of the target charging battery cell is greater than or equal to the full charge cut-off voltage, the target battery cell is withdrawn from the main circuit through the balancing circuit where the target battery cell is located.

6. The method according to claim 5, characterized in that The charging state includes a first charging state and a second charging state, a charging speed of the first charging state is lower than a charging speed of the second charging state; and a charging cut-off voltage of the first charging state is lower than a charging cut-off voltage of the second charging state.

7. The method according to any one of claims 1 to 3, characterized in that The method further comprises: In response to withdrawing the target battery cell from the main circuit, continue to monitor the total voltage of the battery pack, and determine a target battery cell from a plurality of candidate battery cells located in the main circuit of the battery pack when the total voltage of the battery pack meets the state requirement voltage corresponding to the battery pack state; and withdraw the target battery cell from the main circuit through the balancing circuit where the target battery cell is located when the target battery cell meets the cut-off voltage corresponding to the battery pack state; Until the total voltage of the battery pack does not meet the state requirement voltage corresponding to the battery pack state.

8. A cell control device for a battery pack, characterized in that: include: an acquisition module, configured to acquire a battery pack status of the battery pack; a determination module configured to determine a target battery cell from a plurality of candidate battery cells located in a main circuit of the battery pack when the total voltage of the battery pack meets a state requirement voltage corresponding to the state of the battery pack; The adjustment module is configured to, when the target battery cell meets the cut-off voltage corresponding to the battery pack state, remove the target battery cell from the main loop through the balancing circuit where the target battery cell is located.

9. A cell control device for a battery pack, characterized in that: include: a memory configured to store executable instructions; The processor is configured to implement the method according to any one of claims 1 to 7 when executing the executable instructions stored in the memory.

10. A computer-readable storage medium, characterized in that: The device stores executable instructions and is configured to implement the method according to any one of claims 1 to 7 when executed by a processor.

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