Battery equalization control method and device, equipment, storage medium and program product

Abstract

The invention relates to a battery equalization control method and device, equipment, a storage medium and a program product. The method comprises the following steps: acquiring the current capacity and the current temperature of each battery branch in the battery system; determining a target temperature of each battery branch according to the current capacity and the current temperature of each battery branch; and performing thermal management on each battery branch according to the target temperature of each battery branch so as to balance the branch current of the plurality of battery branches. According to the invention, the circulation problem can be reduced and the available capacity of the battery system is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery balancing control method, device, equipment, storage medium and program product. Background Art

[0002] With the development of new energy technologies, batteries have become an indispensable energy storage device in people's lives. At present, multiple battery branches are often connected in parallel to form a battery system. In practical applications, there may be current imbalance and circulation between multiple battery branches, which may easily lead to problems such as difficulty in fully charging the battery and the capacity of the battery system cannot be fully utilized. Summary of the invention

[0003] Based on the above problems, the present application provides a battery balancing control method, device, equipment, storage medium and program product, which can reduce the circulation problem and improve the available capacity of the battery system.

[0004] In a first aspect, the present application provides a battery balancing control method, the method comprising: obtaining the current capacity and current temperature of each battery branch in a battery system; determining the target temperature of each battery branch according to the current capacity and current temperature of each battery branch; performing thermal management on each battery branch according to the target temperature of each battery branch to balance the branch currents of multiple battery branches.

[0005] In the technical solution of the embodiment of the present application, by performing thermal management on each battery branch and adjusting the temperature of each battery branch, the branch resistance of each battery branch is adjusted, and the branch current of multiple battery branches is balanced. In this way, the problem of circulating current can be reduced, and the charging speed of the battery can be adjusted by adjusting the branch current, thereby improving the available capacity of the battery system.

[0006] In some embodiments, the target temperature of each battery branch is determined according to the current capacity and current temperature of each battery branch, including: determining the target resistance relationship between multiple battery branches according to the current capacity of each battery branch; determining the first battery branch and the branch resistance of the first battery branch according to the current temperature of each battery branch; determining the target temperature of each second battery branch except the first battery branch in the multiple battery branches according to the target resistance relationship and the branch resistance of the first battery branch. In the technical solution of the embodiment of the present application, the target resistance relationship is determined by the current capacity, and then the target temperature of each battery branch can be determined according to the target resistance relationship and the current temperature, which provides a basis for subsequent thermal management and makes thermal management more accurate.

[0007] In some embodiments, according to the current temperature of each battery branch, determining the first battery branch and the branch resistance of the first battery branch includes: determining a reference temperature according to the current temperature of each battery branch, and determining the battery branch corresponding to the reference temperature as the first battery branch; according to the current temperature of the first battery branch, searching the branch resistance of the first battery branch in a pre-established temperature resistance table. In the technical solution of the embodiment of the present application, the branch resistance can be determined quickly and accurately according to the temperature by using a pre-established temperature resistance table, thereby providing a basis for subsequently determining the target temperature according to the resistance, thereby improving the thermal management efficiency.

[0008] In some embodiments, according to the target resistance relationship and the branch resistance of the first battery branch, the target temperature of each second battery branch other than the first battery branch in the plurality of battery branches is determined, including: determining the branch resistance of each second battery branch according to the target resistance relationship and the branch resistance of the first battery branch; and searching the target temperature of each second battery branch in a temperature resistance table according to the branch resistance of each second battery branch. In the technical solution of the embodiment of the present application, the target temperature can be determined quickly and accurately according to the branch resistance by using the pre-established temperature resistance table, thereby improving the thermal management efficiency.

[0009] In some embodiments, the target resistance relationship between multiple battery branches is determined according to the current capacity of each battery branch, including: determining the target current relationship between multiple battery branches according to the current capacity of each battery branch; determining the target resistance relationship between multiple battery branches according to the target current relationship between multiple battery branches. In the technical solution of the embodiment of the present application, the target resistance relationship is derived according to the capacity, which provides a basis for subsequent resistance adjustment and thermal management of the battery branches, thereby making thermal management more accurate, thereby balancing the branch currents between the battery branches and reducing the circulation problem.

[0010] In some embodiments, the method further includes: obtaining the temperature change and capacity change for each battery branch; and returning to the step of obtaining the current capacity and current temperature of each battery branch in the battery system when it is determined that at least one of the temperature change and the capacity change meets the correction trigger condition. In the technical solution of the embodiment of the present application, since thermal management affects the charging speed and discharging speed of the battery branch, after the initial thermal management target is reached, the target temperature can be corrected and a new round of thermal management can be started, so as to more accurately adjust the temperature of the battery branch, and then more accurately balance the branch current between the battery branches, reduce the circulation problem; and improve the available capacity of the battery system.

[0011] In a second aspect, the present application further provides a battery balancing control device, the device comprising:

[0012] The capacity and temperature acquisition module is used to obtain the current capacity and current temperature of each battery branch in the battery system;

[0013] A temperature determination module, used to determine a target temperature of each battery branch according to the current capacity and current temperature of each battery branch;

[0014] The thermal management module is used to perform thermal management on each battery branch according to the target temperature of each battery branch to balance the branch currents of multiple battery branches.

[0015] In a third aspect, the present application further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the method of the first aspect when executing the computer program.

[0016] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method of the first aspect is implemented.

[0017] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which implements the method of the first aspect when executed by a processor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the optional embodiments below. The accompanying drawings are only used for the purpose of illustrating the optional embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0019] Figure 1a A schematic diagram of the structure of a thermal management system in some embodiments of the present application;

[0020] Figure 1b A schematic diagram of the structure of a thermal management system in some embodiments of the present application;

[0021] Figure 1c A schematic diagram of the structure of a thermal management system in some embodiments of the present application;

[0022] Figure 2 is a flowchart of a battery balancing control method according to some embodiments of the present application;

[0023] FIG. 3 is a diagram of some embodiments of the present application.

[0024] Figure 4 is a flowchart of steps for determining a target temperature of each battery branch in some embodiments of the present application;

[0025] Figure 5 is a flowchart of the steps of determining the target resistance relationship in some embodiments of the present application;

[0026] Figure 6 is a flowchart of the step of determining the branch resistance of the first battery branch in some embodiments of the present application;

[0027] Figure 7 is a flowchart of the step of determining the target temperature of each second battery branch in some embodiments of the present application;

[0028] Figure 8 is a flow chart of the steps of correcting the target temperature in some embodiments of the present application;

[0029] Fig. 9 is a structural block diagram of a battery balancing control device in some embodiments of the present application;

[0030] Fig.10 is a structural block diagram of a battery balancing control device in some embodiments of the present application;

[0031] Fig.11 It is a diagram of the internal structure of an electronic device according to some embodiments of the present application. DETAILED DESCRIPTION

[0032] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0034] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0035] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0036] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0037] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] With the development of new energy technologies, batteries have become an indispensable energy storage device in people's lives. At present, multiple battery branches are often connected in parallel to form a battery system. In practical applications, there may be temperature differences between multiple battery branches, and temperature differences may cause current imbalance between multiple battery branches, and current imbalance will cause circulation; and the current imbalance between multiple battery branches will also cause different charging speeds of battery branches. After some battery branches are fully charged, the entire battery system stops charging, and other battery branches are difficult to fully charge. Since some battery branches are not fully charged, when the battery system is discharged, the capacity cannot be fully utilized.

[0040] Research on the above-mentioned problem found that the battery temperature affects the battery internal resistance, and the battery internal resistance affects the charging current and the discharging current. Based on this finding, an embodiment of the present application provides a battery balancing control method to obtain the current capacity and current temperature of each battery branch in the battery system; determine the target temperature of each battery branch according to the current capacity and current temperature of each battery branch; and perform thermal management on each battery branch according to the target temperature of each battery branch to balance the branch current of multiple battery branches. The embodiment of the present application performs thermal management on each battery branch, adjusts the temperature of each battery branch, thereby adjusting the branch resistance of each battery branch and balancing the branch current of multiple battery branches. In this way, the problem of circulating current can be reduced, and the charging speed of the battery can be adjusted by adjusting the branch current, so as to improve the available capacity of the battery system.

[0041] The battery system disclosed in the embodiment of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships, or aircraft. Figure 1a , a thermal management system 100 for thermal management of a battery system may include a plurality of heating branches 101, a switch circuit 102, and a controller 103. Among them, the number of heating branches 101 may correspond to the number of battery branches, and each heating branch 101 may include a plurality of heating devices, and the number of heating devices may correspond to the number of batteries in the battery branch. The heating device may include, but is not limited to, various heating films, heating plates, and the like. The switch branch 102 may include a first switch K1 and a plurality of second switches K2, the first switch K1 being connected to the first end of each heating branch 101, respectively, and the second end of each heating branch 101 being connected to each second switch K2 correspondingly. Among them, the first switch K1 and the second switch K2 may include, but are not limited to, various relay switches. The above-mentioned controller 101 includes, but is not limited to, various battery management systems (Battery Management System, BMS), battery management units (Battery Management Unit, BMU), electronic control units (Electronic Control Unit, ECU) of the vehicle, and the like. The controller 103 is connected to each switch in the switch circuit 102.

[0042] According to some embodiments of the present application, referring to Figure 1b and 1c The thermal management system 100 may also include a plurality of cooling branches 104, and the number of cooling branches 104 may correspond to the number of battery branches. Each cooling branch 104 may include, but is not limited to, various water cooling units and cooling water pumps. The water cooling unit may cool the electric cabinet of the battery branch through heat exchange, and the cooling water pump may pump cooling water into the electric cabinet of the battery branch to cool the battery branch. The controller 103 is connected to each cooling branch 104.

[0043] According to some embodiments of the present application, the thermal management system 100 may further include multiple temperature detection devices, which may detect the temperature of the battery system, and the controller 103 is connected to each temperature detection device. The temperature detection device may include but is not limited to various temperature sensors.

[0044] According to some embodiments of the present application, referring to Figure 2 , a battery balancing control method is provided, which is described by taking the application of the method to the controller in FIG1 as an example, and may include the following steps:

[0045] Step 201, obtaining the current capacity and current temperature of each battery branch in the battery system.

[0046] Among them, battery capacity is one of the important performance indicators to measure battery performance, which indicates the amount of electricity discharged by the battery under certain conditions (discharge rate, temperature, termination voltage, etc.). The current capacity can represent the amount of electricity that can be discharged by the battery branch under certain conditions at the current moment.

[0047] The controller can obtain the current capacity of each battery branch in a variety of ways. For example, the controller is a battery management system, which can collect the current capacity of each battery in each battery branch and then calculate the current capacity of each battery branch. Alternatively, the controller is an ECU of the vehicle, which is connected to the battery management system of the battery system and obtains the current capacity of each battery branch from the battery management system.

[0048] The controller is connected to the temperature detection device of each battery branch respectively, and obtains the temperature of the battery branch at the current moment from each temperature detection device to obtain the current temperature.

[0049] Step 202: Determine the target temperature of each battery branch according to the current capacity and current temperature of each battery branch.

[0050] There may be capacity differences and temperature differences between multiple battery branches. The capacity difference will cause the battery branch with high capacity to be fully charged first during charging, and the battery branch with low capacity will be difficult to fully charge. During discharge, the battery branch with low capacity will be emptied first, and the capacity of the battery branch with high capacity will not be fully utilized. The temperature difference will cause the branch resistance between the battery branches to be different, which will in turn cause the branch current between the battery branches to be different, and the different branch currents will lead to different charging and discharging speeds. In the case where there are both capacity differences and temperature differences between the battery branches, the temperature difference may aggravate the problem that the battery branch with low capacity is difficult to fully charge during charging, and the capacity of the battery branch with high capacity is not fully utilized during discharge.

[0051] Based on the above situation, the relationship between capacity and temperature can be preliminarily determined: when charging, the battery branch with low capacity needs to be charged with a large current, and the battery branch with high capacity needs to be charged with a small current. Therefore, the branch resistance of the battery branch with low capacity can be lowered, that is, the temperature of the battery branch with low capacity can be increased, or the branch resistance of the battery branch with high capacity can be increased, that is, the temperature of the battery branch with high capacity can be reduced. When discharging, the battery branch with low capacity needs to be discharged with a small current, and the battery branch with high capacity needs to be discharged with a large current. Therefore, the branch resistance of the battery branch with low capacity can be increased, that is, the temperature of the battery branch with low capacity can be reduced, or the branch resistance of the battery branch with high capacity can be lowered, that is, the temperature of the battery branch with high capacity can be increased.

[0052] Based on the above relationship and capacity difference, the alternative temperature of each battery branch can be preliminarily determined, and then based on the temperature difference between the battery branches and the alternative temperature, the target temperature of each battery branch can be further determined.

[0053] For example, the capacity of battery branch 1 is Q1 and the temperature is T1, and the capacity of battery branch 2 is Q2 and the temperature is T2, wherein capacity Q1 is greater than capacity Q2 and temperature T1 is greater than temperature T2. During charging, based on the capacity difference ΔQ between capacity Q1 and capacity Q2, it is determined that the temperature T2 of battery branch 2 needs to be increased to an alternative temperature Tx, and then based on the temperature difference ΔT between temperature T1 and temperature T2 and the alternative temperature Tx, it can be finally determined that the temperature of battery branch 2 needs to be increased to the target temperature Ty.

[0054] It should be noted that determining the target temperature of each battery branch based on the capacity difference and the temperature difference is not limited to the above method. The corresponding relationship between the capacity and the temperature change can also be pre-calibrated, and then the target temperature of each battery branch is determined based on the corresponding relationship and the capacity difference and the temperature difference.

[0055] Step 203 : performing thermal management on each battery branch according to the target temperature of each battery branch to balance the branch currents of the multiple battery branches.

[0056] Among them, thermal management includes heating and cooling the battery branch. Figure 1a Taking the thermal management system shown in the figure as an example, for any battery branch, if heating is required, the controller first determines the heating branch corresponding to the battery branch and the second switch K2 corresponding to the heating branch, and then controls the first switch K1 and the second switch K2 to close, so that the heating device in the heating branch heats the battery branch. If cooling is required, the controller first determines the cooling branch corresponding to the battery branch, and then controls the cooling branch to cool the battery branch.

[0057] After determining the target temperature of each battery branch, if the target temperature is higher than the current temperature, the battery branch is heated; if the target temperature is lower than the current temperature, the battery branch is cooled.

[0058] The above heating treatment can reduce the branch resistance of the battery branch, thereby increasing the branch current of the battery branch; the above cooling treatment can increase the branch resistance of the battery branch, thereby reducing the branch current of the battery branch. It can be understood that by adjusting the temperature of the battery branch, the branch resistance of the battery branch can be adjusted, thereby achieving the effect of balancing the branch current of the battery branch.

[0059] Reference Figure 3a and 3b , the x-axis is time, the y-axis is current, the positive direction of the y-axis is charging, and the negative direction of the y-axis is discharging. The light gray line corresponds to battery branch 1, and the black line corresponds to battery branch 2. Figure 3aIndicates the case where thermal management is not performed. Taking charging as an example, the branch current of battery branch 1 is greater than the branch current of battery branch 2. Therefore, in the same charging time, battery branch 1 charges more capacity Qm than battery branch 2. Taking discharging as an example, the branch current of battery branch 1 is greater than the branch current of battery branch 2. Therefore, in the same discharging time, battery branch 1 discharges more capacity Qn than battery branch 2. Figure 3b Indicates the situation of thermal management. Taking charging as an example, the branch current of battery branch 1 is greater than the branch current of battery branch 2 at the beginning. Therefore, battery branch 1 charges more capacity Qa than battery branch 2. After thermal management starts, the branch current of battery branch 2 is greater than the branch current of battery branch 1. Battery branch 2 charges more capacity Qb than battery branch 1. When Qa=Qb, the charging capacity of battery branch 1 and battery branch 2 can be made the same in the same time. Taking discharging as an example, the branch current of battery branch 1 is greater than the branch current of battery branch 2 at the beginning. Therefore, battery branch 1 discharges more capacity Qc than battery branch 2. After thermal management starts, the branch current of battery branch 2 is greater than the branch current of battery branch 1. Battery branch 2 discharges more capacity Qd than battery branch 1. When Qc=Qd, the discharge capacity of battery branch 1 and battery branch 2 can be made the same in the same time. By Figure 3a and Figure 3b It can be seen that thermal management can balance the branch currents of the battery branches, change the charging speed and discharging speed of the battery branches, and thus improve the available capacity of the battery system.

[0060] In the above embodiment, the current capacity and current temperature of each battery branch in the battery system are obtained; the target temperature of each battery branch is determined according to the current capacity and current temperature of each battery branch; and each battery branch is thermally managed according to the target temperature of each battery branch to balance the branch current of multiple battery branches. In the technical solution of the embodiment of the present application, by thermally managing each battery branch and adjusting the temperature of each battery branch, the branch resistance of each battery branch is adjusted, and the branch current of multiple battery branches is balanced. In this way, the problem of circulating current can be reduced, and the charging speed of the battery can be adjusted by adjusting the branch current, so as to improve the available capacity of the battery system.

[0061] According to some embodiments of the present application, referring to Figure 4 The process of determining the target temperature of each battery branch according to the current capacity and current temperature of each battery branch may include the following steps:

[0062] Step 301 : determining a target resistance relationship between a plurality of battery branches according to the current capacity of each battery branch.

[0063] The target resistance relationship is the resistance relationship between the multiple battery branches when each battery branch reaches the target capacity. Optionally, when each battery branch reaches the target capacity, the capacity difference between the multiple battery branches is within a preset range.

[0064] According to the system structure of the battery system, a mapping relationship between the capacity relationship and the target resistance relationship of multiple battery branches is determined. After determining the current capacity of each battery branch, the capacity relationship between the multiple battery branches can be determined, and then according to the above mapping relationship and capacity relationship, the target resistance relationship between the multiple battery branches can be determined.

[0065] For example, the capacity relationship of the multiple battery branches is Q1:Q2:Q3, and the target resistance relationship between the multiple battery branches can be determined to be R1:R2:R3 according to the mapping relationship.

[0066] Step 302 : determining a first battery branch and a branch resistance of the first battery branch according to the current temperature of each battery branch.

[0067] The branch resistance is a total equivalent resistance determined according to the connection relationship of the batteries in the battery branch. Optionally, when multiple batteries are connected in series in the battery branch, the branch resistance is the sum of the internal resistances of the multiple batteries in the battery branch.

[0068] A correspondence between temperature and branch resistance is established in advance. After determining the current temperature of each battery branch, a first battery branch is selected from the multiple battery branches according to the current temperatures of the multiple battery branches; then, according to the above correspondence, the branch resistance of the first battery branch corresponding to the current temperature of the first battery branch can be determined.

[0069] Step 303 : determining a target temperature of each second battery branch except the first battery branch among the plurality of battery branches according to the target resistance relationship and the branch resistance of the first battery branch.

[0070] According to the above target resistance relationship and the resistance of the first battery branch, the branch resistance of each second battery branch except the first battery branch can be determined; then according to the above correspondence between temperature and branch resistance, the target temperature of each second battery branch corresponding to the branch resistance of each second battery branch can be determined.

[0071] In the above embodiment, the target resistance relationship between multiple battery branches is determined according to the current capacity of each battery branch; the branch resistance of the first battery branch and the first battery branch is determined according to the current temperature of each battery branch; the target temperature of each second battery branch other than the first battery branch in the multiple battery branches is determined according to the target resistance relationship and the branch resistance of the first battery branch. In the technical solution of the embodiment of the present application, the target resistance relationship is determined by the current capacity, and then the target temperature of each battery branch can be determined according to the target resistance relationship and the current temperature, which provides a basis for subsequent thermal management and makes thermal management more accurate.

[0072] According to some embodiments of the present application, referring to Figure 5 The process of determining the target resistance relationship between the multiple battery branches according to the current capacity of each battery branch may include the following steps:

[0073] Step 401 : determining a target current relationship between a plurality of battery branches according to the current capacity of each battery branch.

[0074] The target current relationship is the current relationship between the multiple battery branches when each battery branch reaches the target capacity. Optionally, when each battery branch reaches the target capacity, the capacity difference between the multiple battery branches is within a preset range.

[0075] After determining the current capacity of each battery branch, the target capacity relationship when each battery branch reaches the target capacity can be determined. Since the battery capacity is the integral of the current I from t0 to t1, that is, there is a proportional relationship between the battery capacity and the current, the target current relationship between multiple battery branches can be determined based on the above target capacity relationship.

[0076] For example, the target capacity relationship between the multiple battery branches is Q1': Q2': Q3'. Since the capacity Q is proportional to the current I, the target current relationship between the multiple battery branches is I1: I2: I3.

[0077] Step 402 : determining a target resistance relationship among a plurality of battery branches according to a target current relationship among a plurality of battery branches.

[0078] According to the parallel connection relationship between multiple battery branches in the battery system, it can be determined that the branch voltages of the multiple battery branches are the same, and according to U=I*R, it can be determined that the current of each battery branch is inversely proportional to the resistance. After determining the target current relationship between the multiple battery branches, the target resistance relationship between the multiple battery branches can be determined according to the inversely proportional relationship between the current and the resistance.

[0079] For example, the target current relationship between the multiple battery branches is I1:I2:I3, and the target resistance relationship between the multiple battery branches can be determined to be R1:R2:R3.

[0080] In the above embodiment, the target current relationship between multiple battery branches is determined according to the current capacity of each battery branch; the target resistance relationship between multiple battery branches is determined according to the target current relationship between multiple battery branches. In the technical solution of the embodiment of the present application, the target resistance relationship is derived according to the capacity, which provides a basis for subsequent resistance adjustment and thermal management of the battery branch, thereby making thermal management more accurate, and then balancing the branch currents between the battery branches and reducing the circulation problem.

[0081] According to some embodiments of the present application, referring to Figure 6 The process of determining the first battery branch and the branch resistance of the first battery branch according to the current temperature of each battery branch may include the following steps:

[0082] Step 501 : determining a reference temperature according to the current temperature of each battery branch, and determining the battery branch corresponding to the reference temperature as the first battery branch.

[0083] In practical applications, thermal management of battery branches needs to be within the battery's allowable temperature range. Therefore, after determining the current temperature of each battery branch, the reference temperature is determined based on the battery's allowable temperature range and the current temperature of each battery branch.

[0084] For example, according to the battery's allowable temperature range and the current temperature of each battery branch, the highest current temperature may be determined as the reference temperature, the lowest current temperature may be determined as the reference temperature, or the average temperature of multiple current temperatures may be determined as the reference temperature. It should be noted that the method for determining the reference temperature is not limited to the above description, and other methods may also be used.

[0085] After the reference temperature is determined, the battery branch corresponding to the reference temperature is determined as the first battery branch. For example, if the highest current temperature is determined as the reference temperature, the battery branch corresponding to the highest current temperature is determined as the first battery branch; if the lowest current temperature is determined as the reference temperature, the battery branch corresponding to the lowest current temperature is determined as the first battery branch; if the average temperature is determined as the reference temperature, the battery branch whose current temperature is closest to the average temperature is determined as the first battery branch.

[0086] Step 502 : searching the branch resistance of the first battery branch in a pre-established temperature resistance table according to the current temperature of the first battery branch.

[0087] A temperature resistance table is pre-established, which includes the correspondence between temperature and resistance. After determining the current temperature of the first battery branch, the current temperature is searched from the temperature resistance table, and the resistance corresponding to the searched current temperature is determined as the branch resistance of the first battery branch.

[0088] For example, the first battery branch is battery branch 1, the current temperature of battery branch 1 is T1, temperature T1 is found from the temperature battery table, and then resistance R1 corresponding to temperature T1 is determined as the branch resistance of the first battery branch.

[0089] In the above embodiment, the reference temperature is determined according to the current temperature of each battery branch, and the battery branch corresponding to the reference temperature is determined as the first battery branch. According to the current temperature of the first battery branch, the branch resistance of the first battery branch is searched in the pre-established temperature resistance table. In the technical solution of the embodiment of the present application, the branch resistance can be determined quickly and accurately according to the temperature by using the pre-established temperature resistance table, thereby providing a basis for the subsequent determination of the target temperature according to the resistance, thereby improving the thermal management efficiency.

[0090] According to some embodiments of the present application, referring to Figure 7 The process of determining the target temperature of each second battery branch except the first battery branch among the plurality of battery branches according to the target resistance relationship and the branch resistance of the first battery branch may include the following steps:

[0091] Step 601 : determining the branch resistance of each second battery branch according to the target resistance relationship and the branch resistance of the first battery branch.

[0092] After the branch resistance of the first battery branch is determined, the branch resistance of each second battery branch can be calculated according to the target resistance relationship and the branch resistance of the first battery branch.

[0093] For example, the first battery branch is battery branch 1, and the branch resistance of battery branch 1 is R1, then according to the target resistance relationship R1:R2:R3, the branch resistance R2 of battery branch 2 and the branch resistance R3 of battery branch 3 can be calculated.

[0094] Step 602 : Look up the target temperature of each second battery branch in a temperature resistance table according to the branch resistance of each second battery branch.

[0095] A temperature resistance table is pre-established, which includes the correspondence between temperature and resistance. For each second battery branch, after determining the branch resistance of the second battery branch, the branch resistance is first found from the temperature resistance table, and then the temperature corresponding to the branch resistance is determined as the target temperature of the second battery branch.

[0096] For example, the second battery branch includes a battery branch 2 and a battery branch 3, wherein the branch resistance of the battery branch 2 is R2, the branch resistance R2 is found from the temperature resistance table, and the temperature T2' corresponding to the branch resistance R2 is determined as the target temperature of the battery branch 2. The branch resistance of the battery branch 3 is R3, the branch resistance R3 is found from the temperature resistance table, and the temperature T3' corresponding to the branch resistance R3 is determined as the target temperature of the battery branch 3.

[0097] In the above embodiment, the branch resistance of each second battery branch is determined according to the target resistance relationship and the branch resistance of the first battery branch; and the target temperature of each second battery branch is found in the temperature resistance table according to the branch resistance of each second battery branch. In the technical solution of the embodiment of the present application, the target temperature can be quickly and accurately determined according to the branch resistance by using the pre-established temperature resistance table, thereby improving the thermal management efficiency.

[0098] Based on the above embodiments, Figure 8 , the embodiment of the present application may also include the following steps:

[0099] Step 701: For each battery branch, obtain the temperature change and capacity change.

[0100] In the process of thermal management of each battery branch, the controller can obtain the temperature of each battery branch from the temperature detection device in real time, and then calculate the temperature change according to the temperature of the battery branch when the thermal management starts and the temperature obtained in real time.

[0101] At the same time, during the charging or discharging process of the battery branch, the controller can also obtain the capacity of each battery branch in real time, and then calculate the capacity change based on the capacity of the battery branch when thermal management starts and the capacity obtained in real time.

[0102] Step 702, when it is determined that at least one of the temperature change amount and the capacity change amount meets the correction trigger condition, return to the step of obtaining the current capacity and current temperature of each battery branch in the battery system.

[0103] If it is determined that the temperature change meets the correction trigger condition, and / or the capacity change meets the correction trigger condition, indicating that the thermal management during charging or discharging has achieved the preliminary set target, then return to the above steps of obtaining the current capacity and current temperature of each battery branch, and redetermine the target temperature of each battery branch, that is, correct the target temperature of each battery branch, and re-perform thermal management according to the corrected target temperature.

[0104] In some embodiments, the method may include: if the temperature change amount is greater than or equal to the first change amount, determining that the temperature change amount meets the correction trigger condition.

[0105] The first change is determined according to the temperature at the start of thermal management and the target temperature. If the temperature change is greater than or equal to the first change, indicating that the temperature of the battery branch has reached the target temperature from the temperature at the start of thermal management, it is determined that the temperature change meets the correction trigger condition.

[0106] For example, the temperature at the start of thermal management is Ta, and the target temperature is Tb, then the first change amount is determined to be m=Tb-Ta.

[0107] In some embodiments, it may include: if the capacity change amount is greater than or equal to the second change amount, determining that the capacity change amount meets the correction trigger condition.

[0108] The second change is determined based on the capacity at the start of thermal management and the target capacity to be achieved by thermal management. If the capacity change is greater than or equal to the second change, indicating that the capacity of the battery branch has reached the target capacity from the start of thermal management, it is determined that the capacity change meets the correction trigger condition.

[0109] For example, the capacity of the battery branch 1 is Qa, and the target capacity is Qb, then the second change n=Qb-Qa is determined.

[0110] In the above embodiment, for each battery branch, the temperature change and capacity change are obtained; when it is determined that at least one of the temperature change and capacity change meets the correction trigger condition, the step of obtaining the current capacity and current temperature of each battery branch in the battery system is returned to execute. In the technical solution of the embodiment of the present application, since thermal management will affect the charging speed and discharging speed of the battery branch, after the initial thermal management target is reached, the target temperature can be corrected and a new round of thermal management can be started, so as to more accurately adjust the temperature of the battery branch, and then more accurately balance the branch current between the battery branches, reduce the circulation problem; and improve the available capacity of the battery system.

[0111] According to some embodiments of the present application, the method may further include: when it is determined that charging or discharging is completed, stopping thermal management of each battery branch.

[0112] Since the battery temperature affects the charging and discharging speeds of the battery, thermal management is usually performed on the battery branch during the charging and discharging process. The branch resistance of the battery branch is adjusted by adjusting the temperature of the battery branch, thereby balancing the branch current of the battery branch. After determining that charging or discharging is completed, thermal management of the battery branch can be stopped, that is, the temperature of the battery branch is no longer adjusted.

[0113] To stop thermal management of the battery branch, the controller can control the first switch and each second switch in the switch circuit to be disconnected, and can also control each water cooling unit and cooling water pump to stop running.

[0114] In the above embodiment, when it is determined that charging or discharging is completed, thermal management of each battery branch is stopped. In the technical solution of the embodiment of the present application, stopping thermal management can reduce the energy consumption of the thermal management system, thereby reducing the energy consumption of the electrical device.

[0115] According to some embodiments of the present application, a battery balancing control method is provided, which is described by taking the application of the method to the controller in FIG. 1 as an example, and may include the following steps:

[0116] Step 1: Obtain the current capacity and current temperature of each battery branch in the battery system.

[0117] Step 2: Determine the target current relationship between the multiple battery branches according to the current capacity of each battery branch.

[0118] Step 3: determine a target resistance relationship between the multiple battery branches according to the target current relationship between the multiple battery branches.

[0119] Step 4: determine a reference temperature according to the current temperature of each battery branch, and determine the battery branch corresponding to the reference temperature as the first battery branch.

[0120] Step 5: according to the current temperature of the first battery branch, search the branch resistance of the first battery branch in a pre-established temperature resistance table.

[0121] Step 6: Determine the branch resistance of each second battery branch according to the target resistance relationship and the branch resistance of the first battery branch.

[0122] Step 7: Look up the target temperature of each second battery branch in a temperature resistance table according to the branch resistance of each second battery branch.

[0123] Step 8: Perform thermal management on each battery branch according to the target temperature of each battery branch to balance the branch currents of the multiple battery branches.

[0124] Step 9: For each battery branch, obtain the temperature change and capacity change.

[0125] Step 10: When it is determined that at least one of the temperature change and the capacity change meets the correction trigger condition, return to step 1.

[0126] Step 11: When it is determined that charging or discharging is completed, stop performing thermal management on each battery branch.

[0127] In the above embodiment, by performing thermal management on each battery branch and adjusting the temperature of each battery branch, the branch resistance of each battery branch is adjusted, and the branch current of multiple battery branches is balanced. In this way, the problem of circulating current can be reduced, and the charging speed of the battery can be adjusted by adjusting the branch current, so that the available capacity of the battery system can be improved.

[0128] It should be understood that, although the various steps in the above flowchart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the above flowchart may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0129] Based on the same inventive concept, the embodiment of the present application also provides a cell balancing control device for implementing the cell balancing control method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more cell balancing control device embodiments provided below can refer to the limitations of the cell balancing control method above, and will not be repeated here.

[0130] According to some embodiments of the present application, referring to Fig. 9 , provides a battery balancing control device, the device comprising:

[0131] The capacity and temperature acquisition module 801 is used to acquire the current capacity and current temperature of each battery branch in the battery system;

[0132] A temperature determination module 802, configured to determine a target temperature of each battery branch according to a current capacity and a current temperature of each battery branch;

[0133] The thermal management module 803 is used to perform thermal management on each battery branch according to the target temperature of each battery branch to balance the branch currents of the multiple battery branches.

[0134] In some embodiments, the temperature determination module 802 is specifically used to determine a target resistance relationship between multiple battery branches based on the current capacity of each battery branch; determine a first battery branch and a branch resistance of the first battery branch based on the current temperature of each battery branch; and determine a target temperature of each second battery branch other than the first battery branch among the multiple battery branches based on the target resistance relationship and the branch resistance of the first battery branch.

[0135] In some embodiments, the temperature determination module 802 is specifically used to determine a reference temperature according to the current temperature of each battery branch, and determine the battery branch corresponding to the reference temperature as the first battery branch; according to the current temperature of the first battery branch, search the branch resistance of the first battery branch in a pre-established temperature resistance table.

[0136] In some embodiments, the temperature determination module 802 is specifically configured to determine the branch resistance of each second battery branch according to the target resistance relationship and the branch resistance of the first battery branch; and to search the target temperature of each second battery branch in the temperature resistance table according to the branch resistance of each second battery branch.

[0137] In some embodiments, the temperature determination module 802 is specifically used to determine the target current relationship between multiple battery branches according to the current capacity of each battery branch; and determine the target resistance relationship between multiple battery branches according to the target current relationship between multiple battery branches.

[0138] In some embodiments, reference Fig.10 , the device further comprises:

[0139] The variation acquisition module 804 is used to acquire the temperature variation and capacity variation of each battery branch;

[0140] The correction module 805 is used to return to the step of obtaining the current capacity and current temperature of each battery branch in the battery system when it is determined that at least one of the temperature change amount and the capacity change amount meets the correction trigger condition.

[0141] In some embodiments, the correction module 805 is specifically configured to determine that the temperature change amount meets the correction trigger condition if the temperature change amount is greater than or equal to the first change amount.

[0142] In some embodiments, the correction module 805 is specifically configured to determine that the capacity change amount meets the correction trigger condition if the capacity change amount is greater than or equal to the second change amount.

[0143] In some embodiments, the thermal management module 803 is further configured to stop thermal management of each battery branch when it is determined that charging or discharging is completed.

[0144] Each module in the above-mentioned battery balancing control device can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor in the electronic device in the form of hardware, or can be stored in the memory of the electronic device in the form of software, so that the processor can call and execute the corresponding operations of each of the above modules.

[0145] According to some embodiments of the present application, an electronic device is provided. The electronic device may be a terminal, and its internal structure diagram may be as follows: Fig.11 As shown. The electronic device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface, the display unit and the input device are connected to the system bus via the input / output interface. The processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the electronic device is used to exchange information between the processor and an external device. The communication interface of the electronic device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a configuration file generation method is implemented. The display unit of the electronic device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the electronic device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the electronic device casing, or an external keyboard, touchpad or mouse.

[0146] Those skilled in the art will understand that Fig.11 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the electronic device to which the scheme of the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0147] According to some embodiments of the present application, there is also provided a non-transitory computer-readable storage medium including instructions, such as a memory including instructions, and the instructions can be executed by a processor of an electronic device to complete the above method. For example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0148] According to some embodiments of the present application, a computer program product is also provided, and when the computer program is executed by a processor, the above method can be implemented. The computer program product includes one or more computer instructions. When these computer instructions are loaded and executed on a computer, part or all of the above method can be implemented in whole or in part according to the process or function described in the embodiment of the present application.

[0149] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0150] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0151] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solutions of the present application in detail, but cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the protection scope of the attached claims described in the present application. Therefore, the protection scope of the patent of this application shall be based on the contents of the attached claims, and the description and drawings can be used to explain the contents of the claims.

Claims

1. A battery balancing control method, characterized in that: The method comprises: Obtain the current capacity and current temperature of each battery branch in the battery system; Determining a target temperature of each of the battery branches according to a current capacity and a current temperature of each of the battery branches; Thermal management is performed on each of the battery branches according to a target temperature of each of the battery branches to balance branch currents of the plurality of battery branches.

2. The method according to claim 1, characterized in that Determining the target temperature of each of the battery branches according to the current capacity and the current temperature of each of the battery branches includes: Determining a target resistance relationship between a plurality of the battery branches according to a current capacity of each of the battery branches; Determining the first battery branch and the branch resistance of the first battery branch according to the current temperature of each of the battery branches; A target temperature of each second battery branch other than the first battery branch in the plurality of battery branches is determined according to the target resistance relationship and the branch resistance of the first battery branch.

3. The method according to claim 2, characterized in that The determining, according to the current temperature of each of the battery branches, the first battery branch and the branch resistance of the first battery branch comprises: Determine a reference temperature according to the current temperature of each of the battery branches, and determine the battery branch corresponding to the reference temperature as the first battery branch; According to the current temperature of the first battery branch, the branch resistance of the first battery branch is searched in a pre-established temperature resistance table.

4. The method according to claim 2 or 3, characterized in that: The step of determining a target temperature of each second battery branch except the first battery branch among the plurality of battery branches according to the target resistance relationship and the branch resistance of the first battery branch comprises: determining a branch resistance of each of the second battery branches according to the target resistance relationship and the branch resistance of the first battery branch; According to the branch resistance of each of the second battery branches, the target temperature of each of the second battery branches is searched in a temperature resistance table.

5. The method according to claim 2, characterized in that: The step of determining a target resistance relationship between the plurality of battery branches according to the current capacity of each of the battery branches comprises: Determining a target current relationship between the plurality of battery branches according to a current capacity of each of the battery branches; A target resistance relationship between the plurality of battery branches is determined according to a target current relationship between the plurality of battery branches.

6. The method according to any one of claims 1 to 5, characterized in that: The method further comprises: For each of the battery branches, obtaining a temperature change and a capacity change; When it is determined that at least one of the temperature change and the capacity change meets the correction trigger condition, the method returns to the step of obtaining the current capacity and the current temperature of each battery branch in the battery system.

7. A battery balancing control device, characterized in that: The device comprises: The capacity and temperature acquisition module is used to obtain the current capacity and current temperature of each battery branch in the battery system; a temperature determination module, configured to determine a target temperature of each of the battery branches according to a current capacity and a current temperature of each of the battery branches; The thermal management module is used to perform thermal management on each of the battery branches according to a target temperature of each of the battery branches, so as to balance branch currents of the plurality of battery branches.

8. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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