Battery pack self-heating system and method

Abstract

The present application discloses a battery pack self-heating system and method, belonging to the field of batteries. The system includes: a target battery pack, including a plurality of sub-battery packs, for providing electric energy; an energy storage module, for storing the electric energy released by the target battery pack and charging the target battery pack with the stored electric energy; a charge-discharge switch group, for controlling the on-off of the charge-discharge circuit between the target battery pack and the energy storage module; a detection module, for detecting the voltage of each sub-battery pack, the voltage of the energy storage module, and the battery temperature of the target battery pack; the control module is respectively connected to the detection module and the charge-discharge switch group, and is used to control the charge-discharge switch group based on the voltage of the plurality of sub-battery packs, the voltage of the energy storage module, and the battery temperature of the target battery pack, so as to realize the charge and discharge between the target battery pack and the energy storage module. The present application realizes the self-heating of the target battery pack through the charge and discharge between the target battery pack and the energy storage module, and improves the self-heating efficiency of the battery pack.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to a battery pack self-heating system and method. Background Art

[0002] As one of the main ways of energy supply, batteries have been widely used in the automotive field. Since the discharge characteristics, service life, etc. of batteries are affected under different temperature conditions, especially in low-temperature environments, the conductivity, electrochemical reaction rate, etc. inside the batteries will decrease, resulting in poor charge and discharge power and reduced durability of the batteries. To solve the above problems, when the battery is in a low-temperature environment, the battery temperature can be increased by external heating or internal heating to ensure the charge and discharge efficiency of the battery.

[0003] In the case of increasing the battery temperature by internal heating (self-heating), a large number of electrical components usually need to be added, so that the battery flows through a large number of electrical components, and heat is generated through the current and the internal resistance of the electrical components, thereby realizing the self-heating of the battery pack. However, due to the relatively precise structure inside the battery pack, the addition of a large number of electrical components not only increases a large amount of cost, but also reduces the stability during the charge and discharge process of the battery pack, increasing the safety risk during the use of the battery. Therefore, the efficiency of the current self-heating method for battery packs is poor. Summary of the Invention

[0004] This application provides a battery pack self-heating system and method, which can improve the efficiency of battery pack self-heating. The technical solutions are as follows:

[0005] On the one hand, a battery pack self-heating system is provided, and the system includes:

[0006] A target battery pack, which includes a plurality of sub-battery packs and is used to provide electrical energy;

[0007] An energy storage module, which is used to store the electrical energy released by the target battery pack and charge the target battery pack through the stored electrical energy;

[0008] A charge and discharge switch group, which is connected between the target battery pack and the energy storage module and is used to control the on-off of the charge and discharge circuit between the target battery pack and the energy storage module;

[0009] A detection module, which is respectively connected to the target battery pack and the energy storage module and is used to detect the voltage of each sub-battery pack in the plurality of sub-battery packs, the voltage of the energy storage module, and the battery temperature of the target battery pack;

[0010] A control module, which is respectively connected to the detection module and the charge and discharge switch group, is configured to control the charge and discharge switch group based on the voltages of the multiple sub-battery packs, the voltage of the energy storage module, and the battery temperature of the target battery pack, so as to achieve charge and discharge between the target battery pack and the energy storage module.

[0011] Optionally, the charge and discharge switch group includes multiple switches. The positive electrode of each sub-battery pack is respectively connected to one of the switches, and the other end of the switch is connected to one end of the energy storage module; the negative electrode of each sub-battery pack is respectively connected to one of the switches, and the other end of the switch is connected to the other end of the energy storage module; one switch is connected between two adjacent sub-battery packs among the multiple sub-battery packs;

[0012] The control module is configured to control the disconnection or closing of the multiple switches to control the on / off of the charge and discharge circuit between a single sub-battery pack in the multiple sub-battery packs and the energy storage module, or control the on / off of the charge and discharge circuit between the series connection path of the multiple sub-battery packs and the energy storage module.

[0013] On the other hand, a method for self-heating of a battery pack applied to the above system is provided, and the method includes:

[0014] Obtaining the battery temperature of the target battery pack through the detection module;

[0015] When the battery temperature of the target battery pack is less than the first temperature threshold, obtaining the voltages of the multiple sub-battery packs included in the target battery pack and the voltage of the energy storage module through the detection module;

[0016] Based on the voltages of the multiple sub-battery packs and the voltage of the energy storage module, controlling the charge and discharge switch group to achieve conduction of the charge and discharge circuit between the target battery pack and the energy storage module;

[0017] During the process of charge and discharge between the target battery pack and the energy storage module, monitoring the battery temperature of the target battery pack through the detection module;

[0018] When it is monitored that the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, controlling the charge and discharge switch group to achieve disconnection of the charge and discharge circuit between the target battery pack and the energy storage module, where the second temperature threshold is greater than the first temperature threshold.

[0019] Optionally, the controlling the charge and discharge switch group based on the voltages of the multiple sub-battery packs and the voltage of the energy storage module to achieve conduction of the charge and discharge circuit between the target battery pack and the energy storage module includes:

[0020] Determine a first sub-battery pack with the maximum voltage from the multiple sub-battery packs;

[0021] When the voltage of the first sub-battery pack is greater than the voltage of the energy storage module and the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is greater than a first voltage threshold, control the charge and discharge switch group to charge the energy storage module cyclically through the multiple sub-battery packs;

[0022] When the absolute value of the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is less than or equal to the first voltage threshold, control the charge and discharge switch group to charge the energy storage module in series through the multiple sub-battery packs;

[0023] When the voltage of the first sub-battery pack is less than the voltage of the energy storage module and the difference between the voltage of the energy storage module and the voltage of the first sub-battery pack is greater than the first voltage threshold, control the charge and discharge switch group to charge the multiple sub-battery packs cyclically through the energy storage module.

[0024] Optionally, the multiple sub-battery packs include two sub-battery packs; controlling the charge and discharge switch group to charge the energy storage module cyclically through the multiple sub-battery packs includes:

[0025] Take the first sub-battery pack as the discharging sub-battery pack, and based on the voltages of the multiple sub-battery packs, determine the discharging loss voltage threshold corresponding to the discharging sub-battery pack;

[0026] Control the switches connected to the positive and negative poles of the discharging sub-battery pack in the charge and discharge switch group to close, and other switches to open, so as to charge the energy storage module through the discharging sub-battery pack;

[0027] During the process of charging the energy storage module through the discharging sub-battery pack, monitor the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the discharging loss voltage of the discharging sub-battery pack through the detection module;

[0028] When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold, the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to the rate threshold, and the discharging loss voltage of the discharging sub-battery pack is greater than or equal to the discharging loss voltage threshold, take another sub-battery pack as the discharging sub-battery pack, and return to the step of determining the discharging loss voltage threshold corresponding to the discharging sub-battery pack based on the voltages of the multiple sub-battery packs until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is less than the rate threshold.

[0029] Optionally, during the process of the discharging sub - battery pack charging the energy storage module, after monitoring the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the discharge loss voltage of the discharging sub - battery pack through the detection module, the method further includes:

[0030] When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, control the charge - discharge switch group to charge the energy storage module by connecting the multiple sub - battery packs in series.

[0031] Optionally, the controlling the charge - discharge switch group to charge the energy storage module by connecting the multiple sub - battery packs in series includes:

[0032] Control the switches on the series connection path of the multiple sub - battery packs to close and other switches to open, so as to charge the energy storage module by connecting the multiple sub - battery packs in series;

[0033] During the process of charging the energy storage module by connecting the multiple sub - battery packs in series, monitor the battery temperature of the target battery pack and the temperature rise rate of the battery temperature of the target battery pack through the detection module;

[0034] When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to the rate threshold, continue to charge the energy storage module by connecting the multiple sub - battery packs in series until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is less than the rate threshold.

[0035] Optionally, during the process of charging the energy storage module by connecting the multiple sub - battery packs in series, after monitoring the battery temperature of the target battery pack and the temperature rise rate of the battery temperature of the target battery pack through the detection module, the method further includes:

[0036] When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, control the charge - discharge switch group to charge the multiple sub - battery packs by circulating through the energy storage module.

[0037] Optionally, the multiple sub - battery packs include two sub - battery packs; the controlling the charge - discharge switch group to charge the multiple sub - battery packs by circulating through the energy storage module includes:

[0038] Determine the second sub - battery pack with the minimum voltage from the multiple sub - battery packs;

[0039] Taking the second sub-battery pack as the charging sub-battery pack, based on the voltage of the energy storage module and the voltage of the charging sub-battery pack, determine the charging rising voltage threshold corresponding to the charging sub-battery pack;

[0040] Control the switches connected to the positive and negative electrodes of the charging sub-battery pack in the charge and discharge switch group to close, and other switches to open, so as to charge the charging sub-battery pack through the energy storage module;

[0041] During the process of charging the charging sub-battery pack by the energy storage module, monitor the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the charging rising voltage of the charging sub-battery pack through the detection module;

[0042] When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold, the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to the rate threshold, and the charging rising voltage of the charging sub-battery pack is greater than or equal to the charging rising voltage threshold, take another sub-battery pack as the charging sub-battery pack, and return to the step of determining the charging rising voltage threshold corresponding to the charging sub-battery pack based on the voltage of the energy storage module and the voltage of the charging sub-battery pack, until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, or the temperature rise rate of the battery temperature is less than the rate threshold.

[0043] Optionally, after monitoring the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the charging rising voltage of the charging sub-battery pack through the detection module during the process of charging the charging sub-battery pack by the energy storage module, the method further includes:

[0044] When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, control the charge and discharge switch group to charge the energy storage module through the multiple sub-battery packs in a cycle.

[0045] Optionally, the method further includes: determining the difference between the maximum voltage and the minimum voltage among the voltages of the multiple sub-battery packs;

[0046] When the difference is greater than the second voltage threshold, determine the voltage change threshold based on the voltage of the energy storage module, the maximum voltage and the minimum voltage;

[0047] Control the charge and discharge switch group to realize the conduction of the charge and discharge loop between the target battery pack and the energy storage module; during the process of charging and discharging between the target battery pack and the energy storage module, monitor the change voltage of the multiple sub-battery packs through the detection module;

[0048] When it is detected that the change voltage of the multiple sub - battery packs is greater than or equal to the voltage change threshold, control the charge - discharge switch group to disconnect the charge - discharge circuit between the target battery pack and the energy storage module.

[0049] On the other hand, a vehicle is provided. The vehicle includes a memory and a controller. The memory is used to store a computer program, and the controller is used to execute the computer program stored on the memory to implement the steps of the battery pack self - heating method described above.

[0050] On the other hand, a computer - readable storage medium is provided. The storage medium stores a computer program, and when the computer program is executed by a controller, the steps of the battery pack self - heating method described above are implemented.

[0051] On the other hand, a computer program product containing instructions is provided. When the instructions run on a computer, the computer is made to execute the steps of the battery pack self - heating method described above.

[0052] The technical solution provided by this application can at least bring the following beneficial effects:

[0053] The detection module detects the voltage of the sub - battery packs in the target battery pack, the voltage of the energy storage module, and the battery temperature of the target battery pack, and determines whether self - heating is required based on the battery temperature of the target battery pack. When it is determined that battery pack self - heating is required, based on the voltage of each sub - battery pack and the voltage of the energy storage module, control the disconnection or closure of the charge - discharge switch group between the target battery pack and the energy storage module, so as to realize the self - heating of the target battery pack through the charge - discharge between the target battery pack and the energy storage module. The battery pack self - heating method provided by this application does not require adding a large number of electrical components, saves costs, improves the stability of the target battery pack during the charge - discharge process, and improves the safety of the battery pack self - heating process. Description of the Drawings

[0054] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0055] Figure 1 is a schematic diagram of a battery pack self - heating system provided by an embodiment of this application;

[0056] Figure 2 is a schematic diagram of another battery pack self - heating system provided by an embodiment of this application;

[0057] Figure 3 It is a flowchart of a battery pack self-heating method provided by an embodiment of the present application;

[0058] Figure 4 It is a flowchart of another battery pack self-heating method provided by an embodiment of the present application;

[0059] Figure 5 It is a flowchart of another battery pack self-heating method provided by an embodiment of the present application;

[0060] Figure 6 It is a flowchart of another battery pack self-heating method provided by an embodiment of the present application;

[0061] Figure 7 It is a flowchart of another battery pack self-heating method provided by an embodiment of the present application;

[0062] Figure 8 It is a flowchart of another battery pack self-heating method provided by an embodiment of the present application;

[0063] Figure 9 It is a schematic structural diagram of a vehicle provided by an embodiment of the present application. Detailed implementation manners

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0065] Please refer to Figure 1 , Figure 1 It is a schematic diagram of a battery pack self-heating system shown according to an exemplary embodiment. The battery pack self-heating system includes a target battery pack 101, an energy storage module 102, a charge and discharge switch group 103, a detection module 104, and a control module 105.

[0066] Among them, the target battery pack 101 includes a plurality of sub-battery packs for providing electric energy. The energy storage module 102 is used to store the electric energy released by the target battery pack 101 and charge the target battery pack 101 with the stored electric energy. The charge and discharge switch group 103 is connected between the target battery pack 101 and the energy storage module 102 for controlling the on-off of the charge and discharge circuit between the target battery pack 101 and the energy storage module 102. The detection module 104 is respectively connected to the target battery pack 101 and the energy storage module 102 for detecting the voltage of each sub-battery pack in the plurality of sub-battery packs, the voltage of the energy storage module 102, and the battery temperature of the target battery pack 101. The control module 105 is respectively connected to the detection module 104 and the charge and discharge switch group 103 for controlling the charge and discharge switch group 103 based on the voltage of the plurality of sub-battery packs, the voltage of the energy storage module 102, and the battery temperature of the target battery pack 101 to realize the charge and discharge between the target battery pack 101 and the energy storage module 102.

[0067] The target battery pack 101 can be the power battery pack of a vehicle, including a plurality of batteries. Through the division of the plurality of batteries, a plurality of sub-battery packs are obtained.

[0068] For the division principle and the number of sub-battery packs, they can be determined based on usage requirements. Exemplarily, the target battery pack 101 can be divided into two sub-battery packs. For example, a plurality of sub-batteries on the left side of the target battery pack are determined as the first sub-battery pack, and a plurality of sub-batteries on the right side of the target battery pack are determined as the second sub-battery pack.

[0069] It should be noted that in the scenario of self-heating of the battery pack, the target battery pack 101 is mainly used to provide electric energy for the energy storage module 102 to increase the battery temperature of the target battery pack through the migration of electrons.

[0070] The energy storage module 102 can be any component capable of storing and releasing electric energy. Exemplarily, the energy storage module 102 can be a single large-capacity capacitor to realize the storage and release of electric energy.

[0071] In some embodiments, the charge and discharge switch group 103 includes a plurality of switches. The positive electrode of each sub-battery pack is respectively connected to one of the switches, and the other end of the switch is connected to one end of the energy storage module 102; the negative electrode of each sub-battery pack is respectively connected to one of the switches, and the other end of the switch is connected to the other end of the energy storage module 102; one switch is connected between two adjacent sub-battery packs among the plurality of sub-battery packs. In this way, the control module 105 is used to control the opening or closing of the plurality of switches to control the on-off of the charge and discharge circuit between a single sub-battery pack in the plurality of sub-battery packs and the energy storage module 102, or control the on-off of the charge and discharge circuit between the series connection path of the plurality of sub-battery packs and the energy storage module 102.

[0072] Exemplarily, as Figure 2 shown, the target battery pack includes sub-battery packs 11 and 12, and the charge and discharge switch group includes five switches, namely SP1, SP2, SP3, SP4, and SS1. The positive electrode of sub-battery pack 11 is connected to one end of switch SP1, and the positive electrode of sub-battery pack 12 is connected to one end of switch SP3. The other ends of switch SP1 and switch SP3 are connected to one end of energy storage module 102. The negative electrode of sub-battery pack 11 is connected to one end of switch SP2, and the negative electrode of sub-battery pack 12 is connected to one end of switch SP4. The other ends of switch SP2 and switch SP4 are connected to the other end of energy storage module 102. A switch SS1 is connected between the negative electrode of sub-battery pack 11 and the positive electrode of sub-battery pack 12.

[0073] It should be noted that the switch can be a high-frequency switch to achieve rapid on / off of the circuits between sub-battery packs and between sub-battery packs and the energy storage module. The control of the high-frequency switch by control module 105 will also generate heat in the circuit, thereby promoting the increase of the battery temperature of target battery pack 101.

[0074] Detection module 104 can include a voltage sensor for detecting the cell voltage of each sub-battery pack and the voltage of energy storage module 101; detection module 104 can also include a temperature sensor for detecting the battery temperature of target battery pack 101.

[0075] The above control module 105 can be the execution entity of the battery pack self-heating method in the embodiments of the present application. The control module 105 can be a general-purpose CPU (Central Processing Unit), NP (Network Processor), microprocessor, or can be one or more integrated circuits for implementing the solution of the present application. For example, ASIC (Application-Specific Integrated Circuit), PLD (Programmable Logic Device) or a combination thereof. The above PLD can be CPLD (Complex Programmable Logic Device), FPGA (Field-Programmable Gate Array), GAL (Generic Array Logic) or any combination thereof.

[0076] Those skilled in the art should understand that the above-mentioned target battery pack 101, energy storage module 102, charge and discharge switch group 103, detection module 104, and control module 105 are only examples. Other existing or future possible battery packs, energy storage modules, charge and discharge switch groups, detection modules, or control modules that can be applied to the embodiments of the present application should also be included within the protection scope of the embodiments of the present application and are hereby incorporated herein by reference.

[0077] It should be noted that the implementation environment described in the embodiments of the present application is for more clearly explaining the technical solutions of the embodiments of the present application and does not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art know that with the evolution of the implementation environment, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0078] Next, a detailed explanation of the battery pack self-heating method provided by the embodiments of the present application will be given.

[0079] Figure 3 It is a flowchart of a battery pack self-heating method provided by the embodiments of the present application, and this method is applied to the above-mentioned control module. Please refer to Figure 3 and this method includes the following steps.

[0080] Step 301: Obtain the battery temperature of the target battery pack through the detection module.

[0081] In some embodiments, the detection module can obtain the battery temperature of the target battery pack in real time and send the real-time obtained battery temperature to the control module.

[0082] The battery temperature of the target battery pack refers to the core temperature of the target battery pack. For example, the detection module can be connected to the cores of each of the multiple sub-battery packs included in the target battery pack to obtain the core temperature of each sub-battery pack.

[0083] In some embodiments, the detection module can use the average temperature of the multiple core temperatures corresponding to the multiple sub-battery packs as the battery temperature of the target battery pack, or can obtain the battery temperature of the target battery pack based on the core temperature of each sub-battery pack according to a preset temperature algorithm.

[0084] Step 302: When the battery temperature of the target battery pack is less than the first temperature threshold, obtain the voltages of the multiple sub-battery packs included in the target battery pack and the voltage of the energy storage module through the detection module.

[0085] When the battery temperature of the target battery pack is less than the first temperature threshold, it indicates that the current battery temperature of the target battery pack is relatively low, which will cause the charge and discharge power of the target battery pack to decrease. Therefore, it is necessary to start the self-heating of the target battery pack (i.e., control the charge and discharge between the target battery pack and the energy storage module).

[0086] In some embodiments, the voltage of the sub-battery pack refers to the voltage of the battery cells in the sub-battery pack, and the voltage of the energy storage module refers to the voltage of the battery cells in the energy storage module. For example, the detection module can be connected to the battery cells of each sub-battery pack to obtain the voltage of the battery cells of each sub-battery pack, and connected to the battery cells of the energy storage module to obtain the voltage of the battery cells of the energy storage module.

[0087] In some other embodiments, the voltage of the sub-battery pack can also refer to the voltage across the sub-battery pack, and the voltage of the energy storage module refers to the voltage across the energy storage module. For example, for any sub-battery pack, the detection module can detect the voltage across the any sub-battery pack.

[0088] In some embodiments, the method further includes: determining the difference between the maximum voltage and the minimum voltage among the voltages of the multiple sub-battery packs; when the difference is greater than the second voltage threshold, determining a voltage change threshold based on the voltage of the energy storage module, the maximum voltage, and the minimum voltage; controlling the charge and discharge switch group to enable the conduction of the charge and discharge circuit between the target battery pack and the energy storage module; during the charge and discharge between the target battery pack and the energy storage module, monitoring the changing voltages of the multiple sub-battery packs through the detection module; when it is monitored that the changing voltages of the multiple sub-battery packs are greater than or equal to the voltage change threshold, controlling the charge and discharge switch group to disconnect the charge and discharge circuit between the target battery pack and the energy storage module.

[0089] In some embodiments, as Figure 4 shown, when the maximum voltage is greater than the voltage of the energy storage module, the charge and discharge circuit between the energy storage module and the sub-battery pack with the maximum voltage can be enabled by controlling the charge and discharge switch group to charge the energy storage module through the sub-battery pack with the maximum voltage; when the maximum voltage is not greater than the voltage of the energy storage module, that is, the maximum voltage is less than or equal to the voltage of the energy storage module, the charge and discharge circuit between the energy storage module and the sub-battery pack with the minimum voltage can be enabled by controlling the charge and discharge switch group to charge the sub-battery pack with the minimum voltage through the energy storage module.

[0090] Combined with Figure 2, taking the target battery pack including two sub - battery packs as an example, where the voltage of sub - battery pack 11 is greater than that of sub - battery pack 12, and the voltage difference between sub - battery pack 11 and sub - battery pack 12 is greater than the second voltage threshold. If the voltage of sub - battery pack 11 is greater than the voltage of the energy storage module, then control switch SP1 and switch SP2 are closed, and control switch SP3, switch SP4, and switch SS1 are opened, and this sub - battery pack 11 charges the energy storage module; if the voltage of sub - battery pack 11 is less than or equal to the voltage of the energy storage module, then control switch SP1, switch SP2, and switch SS1 are opened, and control switch SP3 and switch SP4 are closed, and the energy storage module charges sub - battery pack 12.

[0091] When the sub - battery pack with the maximum voltage charges the energy storage module, the above - mentioned voltage change threshold is the discharge loss voltage threshold. When the energy storage module charges the sub - battery pack with the minimum voltage, the above - mentioned voltage change threshold is the charging rise voltage threshold. When charging the energy storage module through the sub - battery pack with the maximum voltage and the discharge loss voltage of this sub - battery pack with the maximum voltage reaches (is greater than or equal to) the discharge loss voltage threshold, the charging circuit between this sub - battery pack with the maximum voltage and the energy storage module is disconnected by controlling the charge - discharge switch group; when charging the sub - battery pack with the minimum voltage through the energy storage module and the charging rise voltage of this sub - battery pack with the minimum voltage reaches (is greater than or equal to) the charging rise voltage threshold, the charging circuit between the energy storage module and this sub - battery pack with the minimum voltage is disconnected by controlling the charge - discharge switch group.

[0092] The discharge loss voltage threshold and the charging rise voltage threshold can be determined based on the voltage difference between the multiple sub - battery packs. For example, ΔU = 0.8*(Umax - Umin), where Umax refers to the maximum voltage among the voltages of the multiple sub - battery packs, Umin refers to the minimum voltage among the voltages of the multiple sub - battery packs, and 0.8 refers to the corresponding relationship between the discharge loss voltage threshold (or charging rise voltage threshold) and the voltage difference between the sub - battery packs, and can be specifically determined in combination with actual usage requirements. For example, it can also be 0.9, 0.85, etc.

[0093] In some embodiments, when the voltage of the energy storage module is less than the maximum voltage and greater than the minimum voltage, the discharge loss voltage threshold or the charging loss voltage threshold can also be determined through the voltage difference between the maximum voltage and the voltage of the energy storage module, and the voltage difference between the voltage of the energy storage module and the minimum voltage.

[0094] Exemplarily, if the voltage of the energy storage module is less than the maximum voltage and greater than the minimum voltage, that is, the voltage of the energy storage module is between the maximum voltage and the minimum voltage. Assuming the voltage of the energy storage module is 3.5V, the maximum voltage among the voltages of the multiple sub-battery packs is 3.8V, and the minimum voltage is 3.4V. It can be obtained that the voltage difference between the maximum voltage and the voltage of the energy storage module is 0.3V, and the voltage difference between the voltage of the energy storage module and the minimum voltage is 0.1V. This indicates that compared with the voltage difference between the energy storage module and the sub-battery pack with the minimum voltage, the voltage difference between the energy storage module and the sub-battery pack with the maximum voltage is larger. Therefore, the sub-battery pack with the maximum voltage can be used to charge the energy storage module to rapidly reduce the voltage of the sub-battery pack with the maximum voltage, that is, rapidly reduce the voltage difference between the sub-battery packs. Assuming the voltage of the energy storage module is 3.3V, the maximum voltage among the voltages of the multiple sub-battery packs is 3.4V, and the minimum voltage is 3.0V. It can be obtained that the voltage difference between the maximum voltage and the voltage of the energy storage module is 0.1V, and the voltage difference between the voltage of the energy storage module and the minimum voltage is 0.3V. This indicates that compared with the voltage difference between the energy storage module and the sub-battery pack with the maximum voltage, the voltage difference between the energy storage module and the sub-battery pack with the minimum voltage is larger. Therefore, the energy storage module can be used to charge the sub-battery pack with the minimum voltage to rapidly increase the voltage of the sub-battery pack with the minimum voltage, that is, rapidly reduce the voltage difference between the sub-battery packs.

[0095] It should be noted that the main purpose of the above steps is: if the target battery pack needs to increase the battery temperature through self-heating, before realizing the self-heating of the target battery pack, ensure that the voltage difference between the sub-battery packs is within the allowable range (the second voltage threshold). If the voltage difference between the sub-battery packs is large, the voltage difference between the sub-battery packs needs to be controlled within the allowable range first, and then the charge and discharge between the target battery pack and the energy storage module are realized.

[0096] In some other embodiments, in the case where the voltage difference between the sub-battery packs is large, it is also possible not to consider whether the battery temperature of the target battery pack is less than the first temperature threshold, and only need to ensure that the battery temperature of the target battery pack is within the safe range, such as the battery temperature of the target battery pack is less than or equal to the third temperature threshold, that is: in the case where the voltage difference between the sub-battery packs is large, first reduce the voltage difference between the sub-battery packs, and then consider whether it is necessary to realize the self-heating of the target battery pack through the charge and discharge between the target battery pack and the energy storage module.

[0097] Of course, after obtaining the voltages of the multiple sub-battery packs and the voltage of the energy storage module, step 303 can also be directly executed, and the embodiments of the present application do not make any limitations in this regard.

[0098] Step 303: Based on the voltages of the multiple sub-battery packs and the voltage of the energy storage module, control the charge and discharge switch group to realize the conduction of the charge and discharge circuit between the target battery pack and the energy storage module.

[0099] In some embodiments, based on the voltages of the multiple sub-battery packs and the voltage of the energy storage module, the charge and discharge switch group can be controlled through the following steps (1)-(4) to enable the conduction of the charge and discharge circuit between the target battery pack and the energy storage module.

[0100] (1) Determine the first sub-battery pack with the maximum voltage from the multiple sub-battery packs.

[0101] (2) When the voltage of the first sub-battery pack is greater than the voltage of the energy storage module and the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is greater than the first voltage threshold, control the charge and discharge switch group to charge the energy storage module in a cycle through the multiple sub-battery packs.

[0102] If the voltage of the first sub-battery pack is greater than the voltage of the energy storage module and the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is greater than the first voltage threshold, it indicates that the voltage of the first sub-battery pack is large enough compared to the voltage of the energy storage module. Then, the current when the first sub-battery pack charges the energy storage module will be relatively large, ensuring that enough heat is generated during the charge and discharge process, so that the temperature rise rate of the battery temperature of the target battery pack is relatively fast, that is, the self-heating efficiency of the target battery pack is relatively high. Therefore, the rapid temperature rise of the target battery pack can be achieved by charging the energy storage module with a single sub-battery pack.

[0103] In some embodiments, as Figure 5 shown, where Umax refers to the maximum voltage among the voltages of the multiple sub-battery packs (i.e., the voltage of the first sub-battery pack), Uc refers to the voltage of the energy storage module, d refers to the first voltage threshold, and the multiple sub-battery packs include two sub-battery packs. At this time, the first sub-battery pack can be used as the discharging sub-battery pack, and based on the voltages of the multiple sub-battery packs, determine the discharging loss voltage threshold corresponding to the discharging sub-battery pack; control the switches connected to the positive and negative electrodes of the discharging sub-battery pack in the charge and discharge switch group to close, and other switches to open, so as to charge the energy storage module through the discharging sub-battery pack; during the process of the discharging sub-battery pack charging the energy storage module, monitor the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the discharging loss voltage of the discharging sub-battery pack through the detection module; when it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold, the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to the rate threshold, and the discharging loss voltage of the discharging sub-battery pack is greater than or equal to the discharging loss voltage threshold (i.e., reaches the discharging voltage threshold), use the other sub-battery pack as the discharging sub-battery pack, and return to the step of determining the discharging loss voltage threshold corresponding to the discharging sub-battery pack based on the voltages of the multiple sub-battery packs until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is less than the rate threshold.

[0104] During the process of charging the energy storage module with the discharging sub-battery pack, as the charging time increases, the voltage of the discharging sub-battery pack will gradually decrease (i.e., voltage loss occurs). To avoid a large voltage loss in the discharging sub-battery pack, resulting in a large voltage difference between the sub-battery packs and posing a safety hazard, in the embodiments of the present application, a discharging loss voltage threshold can be set based on the voltages of multiple sub-battery packs. When the loss voltage of a single discharge of the discharging sub-battery pack is greater than or equal to the discharging loss voltage threshold, the sub-battery packs other than the currently discharging sub-battery pack are used as the discharging sub-battery pack to discharge the energy storage module, so as to achieve multiple sub-battery packs charging the energy storage module in a cycle (alternately) (i.e., multiple sub-battery packs alternately losing voltage), and avoid a safety hazard caused by excessive single voltage loss of a certain sub-battery pack when the sub-battery pack charges the energy storage module.

[0105] In some embodiments, the discharging loss voltage threshold can be determined by the following formula (1):

[0106]

[0107] where i refers to the i-th discharge cycle, and i is a positive integer. refers to the discharging loss voltage threshold corresponding to the discharging sub-battery pack during the i-th discharge, and ΔU i refers to the voltage difference between the sub-battery packs during the i-th discharge. By way of example, in the case where multiple sub-battery packs include two sub-battery packs, refers to the voltage of the first sub-battery pack (such as Figure 2 the sub-battery pack 11 in) during the i-th discharge, refers to the voltage of the sub-battery packs other than the first sub-battery pack (such as Figure 2 the sub-battery pack 12 in) during the i-th discharge.

[0108] It should be noted that 1.5 in formula (1) refers to the correspondence between the discharging loss voltage threshold and the voltage difference between the sub-battery packs, and this correspondence can be selected according to actual usage requirements. For example, it can also be 1.3 times, 1.7 times, 2 times, etc.

[0109] The temperature rise rate of the battery temperature of the target battery pack can be determined based on the change of the battery temperature of the target battery pack. By way of example, the temperature rise rate of the battery temperature of the target battery pack can be determined based on the rising temperature of the battery temperature of the target battery pack within a target time period (such as within 2S, within 1S, etc.). The specific unit of the temperature rise rate can be selected according to actual usage requirements, such as degrees Celsius per second, degrees Fahrenheit per minute, etc.

[0110] Combined with Figure 2, assuming that the voltage of the sub-battery pack 11 is greater than that of the sub-battery pack 12. When the sub-battery pack 11 is used as the discharging sub-battery pack, control the switches SP1 and SP2 to be closed, and control the switches SP3, SP4, and SS1 to be opened. Use this sub-battery pack 11 as the discharging sub-battery pack to charge the energy storage module. If until the discharging loss voltage of the sub-battery pack 11 is greater than or equal to the discharging loss voltage threshold, the battery temperature of the target battery pack is still less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is still greater than or equal to the rate threshold, then control the switches SP1, SP2, and SS1 to be opened, and control the switches SP3 and SP4 to be closed. Use the sub-battery pack 12 (i.e., the sub-battery pack other than the sub-battery pack 11) as the discharging sub-battery pack to charge the energy storage module, so as to realize charging the energy storage module in a cycle based on multiple (sub-battery pack 11 and sub-battery pack 12).

[0111] Combined with Figure 5 It can be known that the cycling condition for multiple sub-battery packs to cycle and charge the energy storage module is that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack during the cycling process is continuously greater than or equal to the rate threshold. When the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, the self-heating of the target battery pack ends; when the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, the cycling of multiple sub-battery packs to charge the energy storage module ends.

[0112] It should be noted that the temperature of the target battery pack being greater than or equal to the second temperature threshold indicates that the battery temperature of the target battery pack will no longer have an adverse effect on the external charging and discharging power of the target battery pack. Therefore, the self-heating of the target battery pack can be ended.

[0113] As the sub-battery pack cycles to charge the energy storage module, the voltage of the sub-battery pack will gradually decrease, the voltage of the energy storage module will gradually increase, and the voltage difference between the sub-battery pack and the energy storage module will gradually decrease, resulting in a weakening of the current in the charging circuit. Furthermore, the heat generation of the charging circuit will decrease, and the temperature rise rate of the battery temperature of the target battery pack will decrease. When the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, it indicates that the voltage between the current sub-battery pack and the energy storage module is already relatively close. If the self-heating of the target battery pack continues in this way, the temperature rise rate of the battery temperature of the target battery pack will only become smaller and smaller. In order to improve the self-heating efficiency of the target battery pack, it is necessary to adjust the charging and discharging method between the target battery pack and the energy storage module.

[0114] In some embodiments, such as Figure 5As shown, when it is detected that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, the charge-discharge switch group can be controlled to charge the energy storage module by connecting the multiple sub-battery packs in series. The detailed content of charging the energy storage module by connecting the multiple sub-battery packs in series will be introduced in detail in step (3) below and will not be elaborated here.

[0115] (3) When the absolute value of the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is less than or equal to the first voltage threshold, control the charge-discharge switch group to charge the energy storage module by connecting the multiple sub-battery packs in series.

[0116] If the absolute value of the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is less than or equal to the first voltage threshold, it indicates that the voltage of the first sub-battery pack is close to the voltage of the energy storage module. Whether charging the energy storage module through the sub-battery pack or charging the sub-battery pack through the energy storage module, due to the small voltage difference between the two, the current in the charging circuit is also small, and the heat generated during the charge-discharge process is less, resulting in a slow temperature rise rate of the battery temperature of the target battery pack, that is, the self-heating efficiency of the target battery pack is low and cannot meet the requirement of rapid temperature rise of the target battery pack.

[0117] In this case, considering the principle of battery series boosting, multiple sub-battery packs can be connected in series so that the overall voltage of the target battery pack is large enough compared to the voltage of the energy storage module, thereby making the current in the charge-discharge circuit large enough to ensure that enough heat is generated during the charge-discharge process, resulting in a relatively fast temperature rise rate of the battery temperature of the target battery pack, that is, the self-heating efficiency of the target battery pack is relatively high.

[0118] In some embodiments, as Figure 6 shown, the switch on the series connection path of the multiple sub-battery packs can be controlled to close and other switches to open to charge the energy storage module by connecting the multiple sub-battery packs in series; during the process of charging the energy storage module by connecting the multiple sub-battery packs in series, the battery temperature of the target battery pack and the temperature rise rate of the battery temperature of the target battery pack are monitored by the detection module; when it is detected that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to the rate threshold, continue to charge the energy storage module by connecting the multiple sub-battery packs in series until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is less than the rate threshold.

[0119] Combined with Figure 2, when charging the energy storage module by connecting the sub-battery pack 11 and the sub-battery pack 12 in series, the switch SP1, the switch SS1, and the switch SP4 can be controlled to close, and the switch SP2 and the switch SP2 can be controlled to open, so as to realize charging the energy storage module by connecting the sub-battery pack 11 and the sub-battery 12 in series.

[0120] Combined with Figure 6 It can be known that the execution condition for charging the energy storage module by connecting multiple sub-battery packs in series is that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack during the cycle continuously is greater than or equal to the rate threshold. When the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, the self-heating of the target battery pack ends; when the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, charging the energy storage module by connecting multiple sub-battery packs in series ends.

[0121] Combined with the above description, when the temperature of the target battery pack is greater than or equal to the second temperature threshold, it indicates that the battery temperature of the target battery pack will no longer have an adverse effect on the external charging and discharging power of the target battery pack. Therefore, the self-heating of the target battery pack can be ended.

[0122] As the sub-battery packs are connected in series to charge the energy storage module, the overall voltage of the series-connected sub-battery packs will gradually decrease, the voltage of the energy storage module will gradually increase, and the voltage difference between the overall voltage of the series-connected sub-battery packs and the voltage of the energy storage module will gradually decrease, resulting in a decrease in the current in the charging circuit, and further resulting in a decrease in the heat generation of the charging circuit and a decrease in the temperature rise rate of the battery temperature of the target battery pack. When the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, it indicates that the overall voltage of the series-connected sub-battery packs is already relatively close to the voltage of the energy storage module. Continuing to realize the self-heating of the target battery pack in this way, the temperature rise rate of the battery temperature of the target battery pack will only become smaller and smaller. In order to improve the self-heating efficiency of the target battery pack, it is necessary to adjust the charging and discharging method between the target battery pack and the energy storage module.

[0123] In some embodiments, as Figure 6 shown, when it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, the charge and discharge switch group can be controlled to charge the multiple sub-battery packs in a cycle through the energy storage module. The detailed content of charging the multiple sub-battery packs in a cycle through the energy storage module will be introduced in detail in step (4) below and will not be elaborated here.

[0124] (4) When the voltage of the first sub-battery pack is less than the voltage of the energy storage module and the difference between the voltage of the energy storage module and the voltage of the first sub-battery pack is greater than the first voltage threshold, control the charge and discharge switch group to charge the multiple sub-battery packs in a cycle through the energy storage module.

[0125] In some embodiments, as Figure 7 shown, the multiple sub-battery groups include two sub-battery groups; at this time, the second sub-battery group with the minimum voltage can be determined from the multiple sub-battery groups; the second sub-battery group is used as the charging sub-battery group, and based on the voltage of the energy storage module and the voltage of the charging sub-battery group, the charging rising voltage threshold corresponding to the charging sub-battery group is determined; control the switches connected to the positive and negative electrodes of the charging sub-battery group in the charge and discharge switch group to close, and other switches to open, so as to charge the charging sub-battery group through the energy storage module; during the process of charging the charging sub-battery group by the energy storage module, monitor the battery temperature of the target battery group, the temperature rise rate of the battery temperature of the target battery group, and the charging rising voltage of the charging sub-battery group through the detection module; when it is monitored that the battery temperature of the target battery group is less than the second temperature threshold, the temperature rise rate of the battery temperature of the target battery group is greater than or equal to the rate threshold, and the charging rising voltage of the charging sub-battery group is greater than or equal to the charging rising voltage threshold, another sub-battery group is used as the charging sub-battery group, and the step of determining the charging rising voltage threshold corresponding to the charging sub-battery group based on the voltage of the energy storage module and the voltage of the charging sub-battery group is returned until the battery temperature of the target battery group is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is greater than or equal to the rate threshold.

[0126] During the process of charging the charging sub-battery group by the energy storage module, as the charging time increases, the voltage of the charging sub-battery group will gradually rise. In order to avoid a large increase in the voltage of the charging sub-battery group, resulting in a large voltage difference between the sub-battery groups and posing a safety hazard, in the embodiments of the present application, the charging rising voltage threshold can be set based on the voltages of the multiple sub-battery groups. When the voltage that the charging sub-battery group rises by each time is greater than or equal to the charging rising voltage threshold, the sub-battery groups other than the currently discharging sub-battery group are used as the charging sub-battery group, and the energy storage module is used to charge the charging sub-battery group, so as to realize the cyclic (alternating) charging of the multiple sub-battery groups by the energy storage module (that is, the voltages of the multiple sub-battery groups rise alternately), and avoid a safety hazard caused by a large increase in the voltage of a certain sub-battery group when the energy storage module charges the sub-battery group.

[0127] In some embodiments, the charging rising voltage threshold can be determined by the following formula (2):

[0128]

[0129] where i refers to the i-th charging cycle, i is a positive integer, refers to the charging rising voltage threshold corresponding to the charging sub-battery group during the i-th charging, and ΔU i refers to the voltage difference between the sub-battery groups during the i-th charging. By way of example, in the case where the multiple sub-battery groups include two sub-battery groups, Refers to the voltage of the first sub - battery pack (such as the sub - battery pack 11 in Figure 2 ) during the i - th charging, Refers to the voltage of the second sub - battery pack (such as the sub - battery pack 12 in Figure 2 ) during the i - th charging.

[0130] It should be noted that the 1.5 in Formula 2 refers to the corresponding relationship between the charging rising voltage threshold and the voltage difference between the sub - battery packs. This corresponding relationship can be selected according to actual usage requirements. For example, it can also be 1.3 times, 1.7 times, 2 times, etc.

[0131] Combined with Figure 2 , assuming that the voltage of the sub - battery pack 11 is less than the voltage of the sub - battery pack 12. In the case of taking the sub - battery pack 11 as the charging sub - battery pack, control the switches SP1 and SP2 to be closed, control the switches SP3, SP4, and SS1 to be opened. Take this sub - battery pack 11 as the charging sub - battery pack and charge it through this energy storage module. If until the charging rising voltage of the sub - battery pack 11 is greater than or equal to the charging rising voltage threshold, and the battery temperature of the target battery pack is still less than the second temperature threshold, and the temperature rising rate of the battery temperature of the target battery pack is still greater than or equal to the rate threshold, then control the switches SP1, SP2, and SS1 to be opened, control the switches SP3 and SP4 to be closed, and take the sub - battery pack 12 (that is, the sub - battery pack other than the sub - battery pack 11) as the charging sub - battery pack to charge the energy storage module, so as to realize the cyclic charging of the sub - battery pack 11 and the sub - battery pack 12 based on the energy storage module.

[0132] Combined with Figure 7 It can be known that the cyclic condition for the energy storage module to cyclically charge the sub - battery pack 11 and the sub - battery pack 12 is: the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rising rate of the battery temperature of the target battery pack during the cycle continuously is greater than or equal to the rate threshold. When the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, end the self - heating of the target battery pack; when the temperature rising rate of the battery temperature of the target battery pack is less than the rate threshold, end the cyclic charging of the energy storage module for the sub - battery pack 11 and the sub - battery pack 12.

[0133] It should be noted that the temperature of the target battery pack being greater than or equal to the second temperature threshold indicates that the battery temperature of the target battery pack will no longer have an adverse impact on the external charging power of the target battery pack. Therefore, the self - heating of the target battery pack can be ended.

[0134] As the energy storage module cycles to charge the sub-battery packs, the voltage of the energy storage module will gradually increase, the voltage of the sub-battery packs will gradually increase, and the voltage difference between the sub-battery packs and the energy storage module will gradually decrease, resulting in a weakening of the current in the charging circuit, and further resulting in a reduction in the heat generation of the charging circuit and a decrease in the temperature rise rate of the battery temperature of the target battery pack. When the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, it indicates that the voltage between the current sub-battery pack and the energy storage module is already relatively close. If the self-heating of the target battery pack continues in this way, the temperature rise rate of the battery temperature of the target battery pack will only become smaller and smaller. In order to improve the self-heating efficiency of the target battery pack, it is necessary to adjust the charging and discharging method between the target battery pack and the energy storage module.

[0135] In some embodiments, such as Figure 7 shown, when it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, the charge-discharge switch group can be controlled to charge the energy storage module through the multiple sub-battery packs in a cycle.

[0136] Step 304: During the process of charging and discharging between the target battery pack and the energy storage module, monitor the battery temperature of the target battery pack through the detection module.

[0137] Step 305: When it is monitored that the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, control the charge-discharge switch group to disconnect the charge-discharge circuit between the target battery pack and the energy storage module, where the second temperature threshold is greater than the first temperature threshold.

[0138] When it is monitored that the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, control each switch in the charge-discharge switch group to disconnect, thereby disconnecting the charge-discharge circuit between the target battery pack and the energy storage module.

[0139] Next, the overall solution of the embodiment of the present application will be introduced. As Figure 8 shown, where Umax refers to the maximum voltage among the voltages of the multiple sub-battery packs (i.e., the voltage of the first sub-battery pack), Uc refers to the voltage of the energy storage module, and d refers to the first voltage threshold. When the battery temperature of the target battery pack is less than or equal to the first temperature threshold, first determine whether the voltage difference between the multiple sub-battery packs in the target battery pack is greater than the second voltage threshold. When the voltage difference between the multiple sub-battery packs is greater than the second voltage threshold, reduce the voltage difference between the multiple sub-battery packs in the manner shown above Figure 8 shown. Figure 4 shown, to reduce the voltage difference between the multiple sub-battery packs.

[0140] When the voltage difference between multiple sub - battery packs is less than or equal to the second voltage threshold, it indicates that the voltage difference between multiple sub - battery packs of the target battery pack is small. The first sub - battery pack with the highest voltage among the multiple sub - battery packs can be determined, and different charge - discharge methods can be executed by opening or closing multiple switches based on the magnitude relationship between the voltage of the first sub - battery pack and the voltage of the energy storage module.

[0141] When the voltage of the first sub - battery pack is greater than the voltage of the energy storage module and the difference between the voltage of the first sub - battery pack and the voltage of the energy storage module is greater than the first voltage threshold, or when charging multiple sub - battery packs through the energy storage module in a cycle and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, in the manner shown above Figure 5 charge the energy storage module through multiple sub - battery packs in a cycle; when the absolute value of the difference between the voltage of the first sub - battery pack and the voltage of the energy storage module is less than or equal to the first voltage threshold, or when charging the energy storage module through multiple sub - battery packs in a cycle and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, in the manner shown above Figure 6 charge the energy storage module by connecting multiple sub - battery packs in series; when the voltage of the first sub - battery pack is less than the voltage of the energy storage module and the difference between the voltage of the energy storage module and the voltage of the first sub - battery pack is greater than the first voltage threshold, or when the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold during the process of charging the energy storage module by connecting multiple sub - battery packs in series, in the manner shown above Figure 7 charge multiple sub - battery packs through the energy storage module in a cycle.

[0142] Through the above self - heating method, it can be ensured that before the battery temperature of the target battery pack is greater than or equal to the second temperature threshold, the temperature rise rate of the battery temperature remains at a relatively high rate, that is, the battery temperature rises at a relatively high rate, so as to realize the rapid rise of the battery temperature and ensure the self - heating efficiency of the target battery pack. Moreover, when the sub - battery packs and the energy storage module are charged and discharged in a cycle, through the alternating operation of the sub - battery packs (multiple sub - battery packs alternately charge the energy storage module, and the energy storage module alternately charges multiple sub - battery packs), it is ensured that when the self - heating of the target battery pack is realized, the voltages between the sub - battery packs alternately rise or alternately fall, so that the voltage difference between the sub - battery packs always remains within the allowable range, to ensure the safety and stability of the target battery pack during the self - heating process.

[0143] Figure 9 FIG. is a schematic structural diagram of a vehicle provided by an embodiment of the present application. The vehicle 900 includes a memory 901 and a controller 902. The memory 901 is used to store a computer program, and the controller 902 is used to execute the computer program stored on the memory 901 to implement the steps of the above - mentioned battery pack self - heating method.

[0144] The memory 901 may include one or more computer-readable storage media, which may be non-transitory. The memory 901 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash storage devices. In some embodiments, the non-transitory computer-readable storage media in the memory 901 is used to store at least one instruction for being executed by the controller 902 to implement the battery pack self-heating method provided in the method embodiments of the present application.

[0145] The controller 902 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The controller 902 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field Programmable Gate Array), and PLA (Programmable Logic Array). The controller 902 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as the CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the controller 902 may be integrated with a GPU (Graphics Processing Unit), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the controller 902 may further include an AI (Artificial Intelligence) processor, and the AI processor is used to process computational operations related to machine learning.

[0146] Those skilled in the art can understand that Figure 9 the structure shown in does not constitute a limitation on the terminal 900, and it may include more or fewer components than shown in the figure, or combine some components, or adopt a different component layout.

[0147] In some embodiments, a computer-readable storage medium is further provided. A computer program is stored in the storage medium, and when the computer program is executed by the controller, the steps of the battery pack self-heating method in the above embodiments are implemented. For example, the computer-readable storage medium may be ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0148] It should be noted that the computer-readable storage medium mentioned in the embodiments of the present application may be a non-volatile storage medium, in other words, it may be a non-transitory storage medium.

[0149] It should be understood that all or part of the steps of implementing the above embodiments can be realized by software, hardware, firmware, or any combination thereof. When implemented using software, it can be realized in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The computer instructions can be stored in the above computer-readable storage medium.

[0150] That is, in some embodiments, a computer program product containing instructions is also provided. When it runs on a computer, it causes the computer to execute the steps of the battery pack self-heating method described above.

[0151] It should be understood that the "at least one" mentioned herein refers to one or more, and the "multiple" refers to two or more. In the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B can mean A or B. The "and / or" herein is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and roles. Those skilled in the art can understand that the words "first", "second", etc. do not limit the quantity and execution order, and the words "first", "second", etc. do not necessarily limit to be different.

[0152] It should be noted that the information (including but not limited to user equipment information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.), and signals involved in the embodiments of the present application are all authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with the relevant laws, regulations, and standards of relevant countries and regions.

[0153] The above are the embodiments provided by the present application, which are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery pack self-heating method applied to a battery pack self-heating system, characterized in that, the system includes: a target battery pack, the target battery pack includes a plurality of sub-battery packs for providing electric energy; an energy storage module for storing the electric energy released by the target battery pack and charging the target battery pack with the stored electric energy; a charge and discharge switch group connected between the target battery pack and the energy storage module for controlling the on / off of the charge and discharge circuit between the target battery pack and the energy storage module; wherein, the charge and discharge switch group includes a plurality of switches, the positive electrode of each sub-battery pack is respectively connected to one of the switches, and the other end of the switch is connected to one end of the energy storage module; the negative electrode of each sub-battery pack is respectively connected to one of the switches, and the other end of the switch is connected to the other end of the energy storage module; one switch is connected between two adjacent sub-battery packs among the plurality of sub-battery packs; a detection module respectively connected to the target battery pack and the energy storage module for detecting the voltage of each sub-battery pack among the plurality of sub-battery packs, the voltage of the energy storage module, and the battery temperature of the target battery pack; a control module respectively connected to the detection module and the charge and discharge switch group for controlling the charge and discharge switch group based on the voltage of the plurality of sub-battery packs, the voltage of the energy storage module, and the battery temperature of the target battery pack to achieve charge and discharge between the target battery pack and the energy storage module; the control module is further used to control the opening or closing of the plurality of switches to control the on / off of the charge and discharge circuit between a single sub-battery pack and the energy storage module among the plurality of sub-battery packs, or control the on / off of the charge and discharge circuit between the series connection path of the plurality of sub-battery packs and the energy storage module; the method includes: obtaining the battery temperature of the target battery pack through the detection module; when the battery temperature of the target battery pack is less than the first temperature threshold, obtaining the voltages of the plurality of sub-battery packs included in the target battery pack and the voltage of the energy storage module through the detection module; determining a first sub-battery pack with the largest voltage from the plurality of sub-battery packs; when the voltage of the first sub-battery pack is greater than the voltage of the energy storage module and the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is greater than the first voltage threshold, controlling the charge and discharge switch group to charge the energy storage module cyclically through the plurality of sub-battery packs; when the absolute value of the difference between the voltage of the first sub-battery pack and the voltage of the energy storage module is less than or equal to the first voltage threshold, controlling the charge and discharge switch group to charge the energy storage module in series through the plurality of sub-battery packs; when the voltage of the first sub-battery pack is less than the voltage of the energy storage module and the difference between the voltage of the energy storage module and the voltage of the first sub-battery pack is greater than the first voltage threshold, controlling the charge and discharge switch group to charge the plurality of sub-battery packs cyclically through the energy storage module; During the charging and discharging process between the target battery pack and the energy storage module, the battery temperature of the target battery pack is monitored by the detection module; When it is monitored that the battery temperature of the target battery pack is greater than or equal to a second temperature threshold, the charging and discharging switch group is controlled to disconnect the charging and discharging circuit between the target battery pack and the energy storage module, and the second temperature threshold is greater than the first temperature threshold.

2. The method according to claim 1, wherein, the multiple sub-battery packs include two sub-battery packs; the controlling the charging and discharging switch group to charge the energy storage module in a cycle through the multiple sub-battery packs includes: Taking the first sub-battery pack as the discharging sub-battery pack, and determining the discharging loss voltage threshold corresponding to the discharging sub-battery pack based on the voltages of the multiple sub-battery packs; Controlling the switches connected to the positive and negative electrodes of the discharging sub-battery pack in the charging and discharging switch group to close, and other switches to open, so as to charge the energy storage module through the discharging sub-battery pack; During the process of charging the energy storage module by the discharging sub-battery pack, the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the discharging loss voltage of the discharging sub-battery pack are monitored by the detection module; When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold, the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to a rate threshold, and the discharging loss voltage of the discharging sub-battery pack is greater than or equal to the discharging loss voltage threshold, taking another sub-battery pack as the discharging sub-battery pack, and returning to the step of determining the discharging loss voltage threshold corresponding to the discharging sub-battery pack based on the voltages of the multiple sub-battery packs, until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is less than the rate threshold.

3. The method according to claim 2, wherein, after monitoring the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the discharging loss voltage of the discharging sub-battery pack during the process of charging the energy storage module by the discharging sub-battery pack by the detection module, the method further includes: When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, controlling the charging and discharging switch group to charge the energy storage module in series through the multiple sub-battery packs.

4. The method according to claim 1 or 3, wherein, the controlling the charging and discharging switch group to charge the energy storage module in series through the multiple sub-battery packs includes: Controlling the switches on the series connection path of the multiple sub-battery packs to close, and other switches to open, so as to charge the energy storage module in series through the multiple sub-battery packs; During the process of charging the energy storage module in series through the multiple sub-battery packs, the battery temperature of the target battery pack and the temperature rise rate of the battery temperature of the target battery pack are monitored by the detection module; When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to the rate threshold, continue to charge the energy storage module by connecting the multiple sub-battery packs in series until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is less than the rate threshold.

5. The method according to claim 4, wherein, after monitoring the battery temperature of the target battery pack and the temperature rise rate of the battery temperature of the target battery pack by the detection module during the process of charging the energy storage module by connecting the multiple sub-battery packs in series, the method further includes: When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, control the charge and discharge switch group to charge the multiple sub-battery packs in a cycle through the energy storage module.

6. The method according to claim 1 or 5, wherein, the multiple sub-battery packs include two sub-battery packs; the control of the charge and discharge switch group to charge the multiple sub-battery packs in a cycle through the energy storage module includes: Determine the second sub-battery pack with the minimum voltage from the multiple sub-battery packs; Take the second sub-battery pack as the charging sub-battery pack, and based on the voltage of the energy storage module and the voltage of the charging sub-battery pack, determine the charging rising voltage threshold corresponding to the charging sub-battery pack; Control the switches connected to the positive and negative electrodes of the charging sub-battery pack in the charge and discharge switch group to close, and other switches to open, so as to charge the charging sub-battery pack through the energy storage module; During the process of charging the charging sub-battery pack by the energy storage module, monitor the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the charging rising voltage of the charging sub-battery pack through the detection module; When it is monitored that the battery temperature of the target battery pack is less than the second temperature threshold, the temperature rise rate of the battery temperature of the target battery pack is greater than or equal to the rate threshold, and the charging rising voltage of the charging sub-battery pack is greater than or equal to the charging rising voltage threshold, take the other sub-battery pack as the charging sub-battery pack, and return to the step of determining the charging rising voltage threshold corresponding to the charging sub-battery pack based on the voltage of the energy storage module and the voltage of the charging sub-battery pack until the battery temperature of the target battery pack is greater than or equal to the second temperature threshold or the temperature rise rate of the battery temperature is less than the rate threshold.

7. The method according to claim 6, wherein, after monitoring the battery temperature of the target battery pack, the temperature rise rate of the battery temperature of the target battery pack, and the charging rising voltage of the charging sub-battery pack by the detection module during the process of charging the charging sub-battery pack by the energy storage module, the method further includes: When it is detected that the battery temperature of the target battery pack is less than the second temperature threshold and the temperature rise rate of the battery temperature of the target battery pack is less than the rate threshold, control the charge and discharge switch group to charge the energy storage module by cycling through the multiple sub-battery packs.

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