Battery equalization control method, device, equalization control system and power battery system

Abstract

The invention discloses a battery equalization control method, device and system and a power battery system. The battery equalization control method comprises the following steps: acquiring electric quantity information corresponding to each battery pack; according to the electric quantity information of the battery packs, the electric quantity information difference between the battery packs is determined; based on the electric quantity information difference and a preset electric quantity threshold value, determining a to-be-balanced target battery pack in each battery pack and a balance control parameter corresponding to the target battery pack; and carrying out electric quantity balance control on the target battery pack according to the balance control parameter, so that the electric quantity among the battery packs is balanced. According to the invention, the equalization control parameter corresponding to the electric quantity information difference between the battery packs can be matched based on the electric quantity information difference between the battery packs, rapid equalization control of the electric quantity between the battery packs can be realized under the condition of not increasing extra hardware configuration, the efficiency of battery equalization control is improved, and the requirement for rapid equalization of the battery under more complex and special working conditions is met.

Description

Technical Field

[0001] The present application relates to the field of material simulation technology, and in particular to a battery balancing control method, device, balancing control system and power battery system. Background Art

[0002] In the field of new energy battery research and development, the widespread application of new energy vehicles has promoted the rapid development of the power battery industry. As the core component of new energy vehicles, the performance of the power battery system directly affects the performance of the entire vehicle.

[0003] The inconsistency of power battery packs is an important factor leading to the decline in power battery performance. The imbalance of energy between battery packs will reduce battery capacity, energy utilization, and reduce the input and output power levels of the battery pack, shortening the service life of the battery pack.

[0004] At present, traditional balancing control requires the configuration of special balancing devices, which adds extra cost and space to the vehicle system. Moreover, for some special or complex working conditions, the energy difference between battery packs may be high, and the balancing time using traditional balancing solutions is long, and the efficiency of balancing control is low. Summary of the invention

[0005] According to various embodiments of the present application, a battery balancing control method, a battery balancing control system, and a power battery system are provided.

[0006] In a first aspect, the present application provides a battery balancing control method, including: obtaining power information corresponding to each battery pack; determining the power information difference between each battery pack based on the power information of each battery pack; determining the target battery pack to be balanced among each battery pack, and the balancing control parameters corresponding to the target battery pack based on the power information difference and a preset power threshold; performing power balancing control on the target battery pack according to the balancing control parameters to balance the power between each battery pack.

[0007] Through the above method, the present application can match the corresponding balancing control parameters based on the power information difference between battery packs, ensuring that without adding additional hardware configuration, it can achieve rapid balancing control of the power between battery packs, improve the efficiency of battery balancing control, and meet the needs of rapid battery balancing under more complex and special working conditions.

[0008] In a second aspect, the present application provides a battery balancing control device, the system comprising:

[0009] An acquisition module is used to obtain the power information corresponding to each battery pack;

[0010] A processing module, configured to determine a power information difference between the battery packs according to the power information of each battery pack; and determine a target battery pack to be balanced among the battery packs, and a balancing control parameter corresponding to the target battery pack based on the power information difference and a preset power threshold;

[0011] The balancing module is used to perform power balancing control on the target battery pack according to the balancing control parameter to balance the power between the battery packs.

[0012] In a third aspect, the present application provides a balancing control system, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements any one of the methods described in the first aspect when executing the computer program.

[0013] In a fourth aspect, the present application provides a power battery system, which includes the balancing control system described in the third aspect and at least two battery packs, wherein the balancing control system is used to control the power balancing of each of the battery packs.

[0014] In a fifth aspect, the present application provides an electric vehicle, comprising the power battery system described in the fourth aspect.

[0015] In a sixth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements any one of the methods described in the first aspect.

[0016] In a seventh aspect, the present application provides a computer program product, which, when executed on an electrical device, enables the electrical device to execute any of the methods described in the first aspect.

[0017] It can be understood that the beneficial effects of the second to seventh aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of an application scenario of a battery pack balancing control architecture provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the implementation flow of the battery balancing control method provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of a circuit structure of a battery pack balancing control provided in an embodiment of the present application;

[0022] Figure 4 A schematic diagram of a specific implementation flow of the balancing control provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of a circuit structure of a battery pack balancing control provided by another embodiment of the present application;

[0024] Figure 6 A schematic diagram of a circuit structure of a battery pack balancing control provided by another embodiment of the present application;

[0025] Figure 7 A schematic diagram of a circuit structure of a battery pack balancing control provided by another embodiment of the present application;

[0026] Figure 8 A schematic diagram of the structure of a DC-DC converter provided in an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of the structure of the BMS provided in the embodiment of the present application;

[0028] Fig.10 A schematic diagram of the structure of the BIC provided in the embodiment of the present application;

[0029] Fig.11 A schematic diagram of the structure of a battery balancing control device provided in an embodiment of the present application;

[0030] Fig.12 A schematic diagram of the structure of a balancing control system provided in an embodiment of the present application;

[0031] Fig.13 A schematic diagram of the structure of a power battery system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following embodiments of the technical solution of the present application are 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] With the rapid development of new energy vehicle technology, the requirements for the performance, endurance and service life of new energy vehicle batteries are becoming increasingly higher. Due to the differences in the manufacturing process, environmental parameters and other factors of the battery cells in the battery pack, there will be inconsistencies between the battery cells; and for power batteries with at least two or more battery packs connected in parallel, there may be a high energy difference between the battery packs.

[0038] Traditional battery balancing mainly uses the parallel resistance of battery cells to achieve balancing control between battery cells in the battery pack; the existing balancing control scheme between battery packs also requires the configuration of additional balancing devices, which adds additional cost and space to the vehicle system. Moreover, when the energy difference between battery packs is large, in some complex or special working conditions (such as battery replacement conditions), it is necessary to achieve rapid balancing between battery packs. Traditional balancing devices have a long balancing time and low balancing control efficiency, which cannot meet the requirements of rapid balancing of battery packs.

[0039] In response to the above problems, an embodiment of the present application provides a battery balancing control method, which is based on the power battery system of an electric vehicle. Without adding additional configuration, it can achieve rapid balancing between battery packs based on the existing system architecture, improve the balancing control efficiency, and meet the rapid balancing requirements in more application scenarios; at the same time, it can be implemented in the original hardware architecture of the electric vehicle, without adding additional hardware configuration and occupying the space of the entire vehicle, which greatly saves costs.

[0040] The specific implementation architecture of the battery balancing control method is introduced below through an embodiment.

[0041] See also Figure 1 , Figure 1 This is a schematic diagram of an application scenario of the battery balancing control architecture provided in the embodiment of the present application. Figure 1 As shown, the battery balancing control architecture may include two or more battery packs (e.g., battery pack 1 to battery pack n), a battery management module and a balancing control module; wherein each battery pack is connected in parallel; the battery management module is respectively connected to each battery pack to obtain the power information of each battery pack, and determines the battery pack that needs to be balanced and the corresponding balancing control parameters according to the power information; the battery management module is communicatively connected to the balancing control module, and the balancing control parameters corresponding to the battery pack that needs to be balanced are sent to the balancing control module; the balancing control module is connected to each battery pack to perform balancing control on the battery pack that needs to be balanced.

[0042] Exemplarily, the battery management module may include a battery management system (BMS) and a battery information collector (BIC) in each battery pack; the BIC is in communication with the BMS. The BIC collects the power information of each battery pack and sends the power information to the BMS; the BMS calculates the power information difference between the battery packs based on the power information of each battery pack, and determines the battery pack that needs to be balanced and the corresponding balancing control parameters based on the power information difference.

[0043] Exemplarily, the battery balancing control module may include a voltage converter, an on-board charger, and an on-board load. The voltage converter may be connected to the on-board charger and the on-board load, respectively; the voltage converter may be a DC-DC converter. The DC-DC converter is connected to the BMS for communication, receives the balancing control parameters sent by the BMS, and combines the on-board charger or the on-board load to realize fast balancing control of the battery packs that need balancing, so that the power between the battery packs is balanced.

[0044] It should be noted that, in order to facilitate the overall description of the solution, the above-mentioned battery balancing control architecture only schematically illustrates the flow of information transmission between the modules, and is not used to indicate the specific connection method between the modules; the specific architecture (such as the battery management module and the balancing control module, and the specific connection method between the two and the battery pack) can be confirmed and divided based on the connection relationship between the original components of the electric vehicle, including but not limited to the above-mentioned architecture form.

[0045] Through the embodiments of the present application, based on the original power battery system of the electric vehicle, by determining the balancing parameters corresponding to the power information difference, rapid balancing between battery packs can be achieved without increasing additional hardware costs, thereby improving the balancing control efficiency between battery packs and meeting the rapid balancing requirements in different application scenarios.

[0046] The specific implementation process of the battery balancing control method will be further described below through embodiments.

[0047] See also Figure 2 , Figure 2 : is a schematic diagram of the implementation flow of the battery balancing control method provided in the embodiment of the present application. The execution subject of the method can be a balancing control system or a power battery system of an electric vehicle, or an electric vehicle equipped with a power battery system or a balancing control system; Figure 2 As shown, the method may include the following steps:

[0048] S201, obtaining power information corresponding to each battery pack.

[0049] In some embodiments, the balancing control system is used as an example to illustrate the execution subject. In the existing system architecture of electric vehicles, at least two battery packs may be included, and each battery pack may include a plurality of battery cells connected in series. Figure 3 As shown, taking two battery packs as an example, the existing system architecture of the electric vehicle may include a first battery pack and a second battery pack. The power of the battery pack may be voltage information or state of charge (SOC) information of the battery pack.

[0050] Each battery pack is equipped with a BMS and a BIC, which can be connected via two Controller Area Network (CAN) buses. The BIC can collect the power information of the battery pack, such as voltage, and transmit the voltage information to the BMS via the CAN bus. The BMS can obtain the voltage of each battery pack, or calculate the state of charge (SOC), i.e. the remaining power, of each battery pack.

[0051] For example, the BIC can collect the voltage of the battery cells in each battery pack and transmit the voltage of the battery cells to the BMS through the CAN bus. The BMS calculates the voltage or SOC of the battery pack based on the battery cells in series. For example, each battery pack can correspond to multiple BICs and one BMS. Each BIC collects the voltage of each battery cell and transmits it to the BMS for further calculation. The BIC can also collect the temperature of the battery to ensure the safety of the battery operation.

[0052] For example, Figure 8As shown, the BMS may include a main control module, such as a central processing unit (CPU); the BMS may also include a CAN communication module, and communicate with other modules based on the high-level interface CANH and the low-level interface CANL of the CAN communication module. For example, the battery information sent by the BIC is received, and the battery information may include the voltage information of the battery cell and the temperature information of the battery system, etc.; and the balancing control parameters are sent to the balancing control module.

[0053] like Fig.10 As shown, the BIC may include a main control module, such as a central processing unit (CPU); the BIC may also include a voltage and temperature acquisition module for collecting the voltage of the battery cell and the temperature of the battery system; the BIC may also include a CAN communication module, and communicate with other modules based on the high-level interface CANH and the low-level interface CANL of the CAN communication module. For example, the main control module receives the voltage information and temperature information sent by the voltage and temperature acquisition module, and sends the voltage information of the battery cell and the temperature information of the battery system to the BMS through the bus of the CAN communication module. The BIC also includes a battery cell balancing control module for controlling the power balancing between the battery cells in the battery pack.

[0054] It should be noted that the BMS can obtain the power information of its own battery pack, and can also obtain the power information of other battery packs through bus communication; the power information of each battery pack can also include the attribute information of the battery pack, such as the battery pack identification.

[0055] S202, determining the power information difference between the battery packs according to the power information of the battery packs.

[0056] In some embodiments, the BMS may calculate the power information difference between the battery packs based on the acquired power information of each battery pack.

[0057] Exemplarily, if the system architecture includes two battery packs, such as a first battery pack and a second battery pack, the power information difference between the first battery pack and the second battery pack is calculated; if there are three or more battery packs, the power information difference between any two battery packs can be calculated separately to obtain multiple power information differences.

[0058] In some embodiments, the power information includes voltage information and / or state of charge; and determining the power information difference between the battery packs according to the power information of each battery pack includes:

[0059] The power information difference between the battery packs is determined based on the voltage information and / or the state of charge of each battery pack.

[0060] The power information difference may be a voltage difference or a state of charge difference of the battery pack. Due to differences in battery manufacturing processes and environments, there may be inconsistencies between each battery cell in the battery pack, which may lead to a greater power information difference between each battery pack.

[0061] S203 , determining a target battery pack to be balanced among the battery packs and a balancing control parameter corresponding to the target battery pack based on the power information difference and a preset power threshold.

[0062] In some embodiments, there may be multiple preset power thresholds, and corresponding levels of balancing control parameters are activated for power thresholds of different levels reached by the power information difference.

[0063] Exemplarily, different power thresholds can be set in the BMS, for example, a first power threshold, a second power threshold, and a third power threshold, wherein the first power threshold is less than the second power threshold, and the second power threshold is less than the third power threshold. Accordingly, each power threshold can correspond to a balancing control parameter, for example, the balancing control parameter can include a first control parameter, a second control parameter, and a third control parameter; based on the power information difference, power thresholds of different levels are met to achieve rapid balancing requirements under different working conditions.

[0064] Exemplarily, the first power threshold is 1% (corresponding to the first control parameter), the second power threshold is 2% (corresponding to the second control parameter), and the third power threshold is 3% (corresponding to the third control parameter). Based on the comparison results of the power information difference and each power threshold, the corresponding control parameter can be determined. For example, if the power information difference is 2.5% and meets the second power threshold, the second control parameter is determined. The input power or output power of the battery pack corresponding to the third control parameter during the balancing process can be greater than that corresponding to the second control parameter, and the input power or output power of the battery pack corresponding to the second control parameter during the balancing control process is greater than that corresponding to the first control parameter, so that when the power information difference between the battery packs is large, fast balancing of different needs can be achieved.

[0065] Correspondingly, the balancing control parameters may also be used to set the control power and control time corresponding to the balancing process based on the power information difference between the battery packs and the power information of the target battery to be balanced, thereby ensuring the reliability and accuracy of the balancing process.

[0066] For example, Figure 3As shown, when the power information difference between the first battery pack and the second battery pack meets the power threshold, the BMS determines the battery pack that needs to be balanced based on the power information of each battery pack and the power information difference between the two. For example, if the power information of the first battery pack is 4%, the power information of the second battery pack is 6%, and the power threshold is 1%, and the power information difference between the two meets the power threshold, then the first battery pack or the second battery pack can be used as the target battery pack to be balanced. When there are multiple battery packs, the number of target battery packs to be balanced can also be multiple, which can be determined specifically based on the power information of each battery pack and the power information difference with other battery packs. For example, if battery pack A is 4%, battery pack B is 5%, and battery pack C is 7%, then battery pack A and battery pack C can be used as target battery packs, and the balancing control parameters corresponding to battery pack A and battery pack C, respectively, can be determined.

[0067] Exemplarily, the balancing control parameters may include at least one of the following: discharging a high-energy battery pack to keep it consistent with a low-energy battery pack; or charging a low-energy battery pack to keep it consistent with a high-energy battery pack; or transferring the power of a high-energy battery pack to a low-energy battery pack.

[0068] For example, for a system architecture with multiple battery packs, when the power information difference between the battery packs meets the power threshold, multiple target battery packs to be balanced can be determined based on the power information of the battery packs themselves, so that the corresponding control parameters can be determined for the power information of each battery pack. For example, the above-mentioned battery pack A can correspond to the control parameters of charging, and battery pack C can correspond to the control parameters of discharging, or the power of battery pack C can be transferred to the control parameters of battery pack A.

[0069] It should be noted that, based on the different numbers of battery packs and the power information differences between battery packs satisfying different power thresholds, different balancing control parameters can be adapted for different battery packs, which can be specifically set according to actual working conditions, including but not limited to the above-mentioned adaptation method and balancing control method.

[0070] S204, performing power balancing control on the target battery pack according to the balancing control parameter to balance the power among the battery packs.

[0071] In some embodiments, Figure 3 As shown, after determining the balancing control parameters, the BMS can send a startup message and specific balancing control parameters to the balancing control module, instructing the balancing control module to start power balancing control for the corresponding target battery pack.

[0072] For example, during the battery pack balancing process, the power information between the balanced battery packs may not be completely consistent, that is, there is a power information difference between the battery packs but it is less than the power threshold. For example, battery pack A is 4%, battery pack B is 5%, and battery pack C is 7%. Battery pack A and battery pack C are used as target battery packs, then battery pack A can be charged to 5.2% and battery pack C can be discharged to 5.5%.

[0073] It should be noted that the power information of the above-mentioned battery pack is only illustrative through percentage values, and the specific amount can be determined according to actual application conditions.

[0074] In addition, during the process of power balancing control of the battery pack, the BMS will continuously monitor the power information of the battery pack to ensure that the target power value of the balance is reached; or based on the balancing control time set in the balancing parameters, the balancing will be stopped after the balancing control time is reached.

[0075] like Figure 3 As shown, the BMS of the battery pack can communicate with the balancing control module through the CAN bus, and send the start and stop messages of the balancing control and the balancing control parameters to the balancing control module. K1 and K2 are circuit switches, respectively, and F1 is the protection resistor of the battery pack.

[0076] Through the embodiments of the present application, based on the original power battery system of the electric vehicle, by determining the balancing parameters corresponding to the power information difference, it is possible to achieve rapid balancing between battery packs without increasing additional hardware costs, improve the balancing control efficiency between battery packs, and meet the rapid balancing needs in different application scenarios; at the same time, by dividing the power thresholds into different levels, adapting different levels of balancing parameters to meet different levels of power thresholds, and adapting different balancing parameters to different battery packs, it is possible to meet the needs for rapid balancing under a variety of application conditions, achieve rapid balancing of power between battery packs, and improve the accuracy and reliability of battery pack balancing.

[0077] Based on the above overall implementation process, the implementation process of the equalization parameters is further introduced below through specific embodiments.

[0078] See also Figure 4 , Figure 4 This is a schematic diagram of a specific implementation process of the balancing control provided in the embodiment of the present application. Figure 4 As shown, the implementation process of the balancing control may include the following steps:

[0079] S2031, when the power information difference is greater than the power threshold, determining a target battery pack having a power information difference and a control power corresponding to the target battery pack.

[0080] In some embodiments, the balancing control parameter may include a control power, where the control power is used to indicate a speed of performing power balancing control on the target battery pack.

[0081] Exemplarily, based on the control power, the battery management module can send a power control instruction to the balancing control module to instruct the balancing control module to use an operating power when performing battery balancing. The operating power of the balancing control module can be adjusted based on the control power in different balancing control parameters. When the balancing control module works under different control powers, the corresponding balancing speeds achieved are different.

[0082] For example, when the power information difference between battery packs is large, a higher control power is set in the balancing control parameters, so that a higher working power can be indicated to the balancing control module, controlling the balancing control module to increase the working power, increase the balancing speed, shorten the balancing time, and achieve fast balancing.

[0083] In one case, the output power of the battery pack can be equivalent to the input power of the balancing control module. In another case, the output power of the balancing control module can be equivalent to the input power of the battery pack. Therefore, by controlling the power of the balancing control module and adapting to the power information difference between battery packs under different working conditions, rapid balancing of the battery pack power under different working conditions can be achieved.

[0084] S2041, when the power information of the first battery pack is less than the power information of the second battery pack, charge balancing control is performed on the first battery pack according to the charge balancing control power to balance the power between the first battery pack and the second battery pack.

[0085] The first battery pack and the second battery pack are any two battery packs among the battery packs, and the first battery pack is a target battery pack to be balanced. The power information difference between the first battery pack and the second battery pack meets the power threshold, and the control power includes the charge balancing control power.

[0086] For example, two battery packs are used as an example to illustrate the implementation process of balancing control. Figure 5 As shown, the balancing control module may include a DC-DC converter and an on-board charger, for example, the on-board charger may be a 12V power supply.

[0087] Among them, Fig. 9As shown, the DC-DC converter may include a main control module, such as a central processing unit (CPU); the DC-DC converter may also include a voltage, current, and temperature detection module for detecting the voltage, current, and temperature of the DC-DC converter to ensure its normal operation; the DC-DC converter also includes a power control module, which controls the actual working power during the balancing process by receiving the power control instruction of the BMS; the DC-DC converter also includes a CAN communication module, and communicates with other modules based on the high-level interface CANH and the low-level interface CANL of the CAN communication module. For example, after the main control module receives the information sent by the voltage, current, and temperature detection module, it sends the information to the BMS through the bus of the CAN communication module to monitor its status; after the main control module receives the control power through the CAN communication module, it sends the corresponding power control instruction to the power control module to control its actual working power during the balancing process, for example, the power control instruction may include the charging balancing control power; based on the power control instruction, the actual working power is controlled, and the voltage of the on-board charger is boosted and converted according to the charging balancing control power to charge the battery pack to achieve rapid balancing.

[0088] Accordingly, charging equalization control is performed on the first battery pack according to the charging equalization control power, including:

[0089] According to the charge balancing control power, the charge balancing control is performed on the first battery pack through the on-board charger.

[0090] Exemplarily, when the power level of the first battery pack is lower than that of the second battery pack, a DC-DC converter can be used to boost the voltage, and the vehicle charger can charge the first battery pack so that the power level of the first battery pack is balanced with that of the second battery pack, and the power level information difference between the two is smaller than a power level threshold, or when there are multiple levels of power level thresholds, the power level information difference is smaller than the lowest power level threshold.

[0091] For example, when rapid balancing control of the target battery pack is required, the power of the DC-DC converter can be increased. The voltage of the on-board charger is fixed and boosted by the DCDC converter. By increasing the power of the DCDC converter, the input current of the battery pack can be increased, speeding up the charging process and achieving rapid balancing.

[0092] S2042, when the power information of the first battery pack is less than the power information of the second battery pack, discharge balancing control is performed on the second battery pack according to the discharge balancing control power to balance the power between the second battery pack and the first battery pack.

[0093] The first battery pack and the second battery pack are any two battery packs among the battery packs, and the second battery pack is the target battery pack to be balanced. The power information difference between the first battery pack and the second battery pack meets the power threshold, and the control power includes the discharge balancing control power.

[0094] like Figure 6 As shown, the balancing control module may include a DC-DC converter and a vehicle load, and the vehicle load may include a low-voltage 12V load or a high-voltage load, etc.

[0095] Exemplarily, after receiving the power control instruction through the CAN communication module, the DC-DC converter main control module sends a power control instruction corresponding to the control power to the power control module to control its actual working power during the balancing process. The power control instruction may be a power control instruction corresponding to the discharge balancing control power. Based on the power control instruction, the actual working power of the DC-DC converter is controlled, the voltage of the battery pack is stepped down, and the discharge of the battery pack is controlled based on the vehicle load to achieve rapid balancing.

[0096] Correspondingly, performing discharge balance control on the second battery pack according to the discharge balance control power includes:

[0097] According to the discharge balancing control power, the discharge balancing control is performed on the second battery pack through the vehicle load.

[0098] Exemplarily, when the power level of the first battery pack is lower than that of the second battery pack, a DC-DC converter can be used to reduce the voltage and discharge the second battery pack based on the vehicle load, so that the power level of the first battery pack is balanced with the power level of the second battery pack, and the power level information difference between the two is less than a power level threshold, or when there are multiple levels of power level thresholds, the power level information difference is less than the lowest power level threshold.

[0099] For example, when rapid balancing control of the target battery pack is required, the power of the DC-DC converter can be increased. The voltage of the vehicle load is fixed. For example, when the vehicle load is a 12V low-voltage load, the voltage is stepped down by the DCDC converter. By increasing the power of the DC-DC converter, the output current of the battery pack and the current at the load end can be increased, thereby accelerating the discharge process and achieving rapid balancing.

[0100] In addition, electric vehicles can be connected to different loads, such as some high-voltage loads. By controlling the power of the DC-DC converter through the BMS, different loads can be coordinated to support discharge balancing based on different powers.

[0101] It can be understood that the operation of charging or discharging the target battery pack can be determined based on the actual working conditions, according to the power information difference between the battery packs and the power information of the battery packs. For example, when the on-board charger has sufficient power, the power of the first battery pack is 60%, and the power of the second battery pack is 70%. At this time, the battery system is still in a state of high power and has a certain battery life. To ensure the normal operation of the battery, the first battery pack can be quickly charged through the on-board battery to achieve power balance. If the power of the first battery pack is 5% and the second battery pack is 7%, the power of both battery packs is low and the battery life is short, then you can choose to discharge the second battery pack to balance the power of the two, so as to facilitate the subsequent charging of the entire battery system.

[0102] S2043, when the power information of the first battery pack is less than the power information of the second battery pack, power transfer balancing control is performed on the first battery pack and the second battery pack according to the power transfer balancing control power to balance the power between the first battery pack and the second battery pack.

[0103] Among them, the first battery pack and the second battery pack are any two battery packs among the battery packs, and the first battery pack and the second battery pack are target battery packs to be balanced, the power information difference between the first battery pack and the second battery pack meets the power threshold, and the control power includes power transfer balancing control power.

[0104] like Figure 7 As shown, the control power can also include power transfer and balancing control power, that is, the second battery pack is stepped down through the DC-DC converter, the power of the second battery pack is transferred to the vehicle charger (12V power supply), and then the voltage of the vehicle charger (12V power supply) is boosted through the DC-DC converter to charge the first battery pack.

[0105] Accordingly, according to the power transfer balancing control power, the first battery pack and the second battery pack are controlled to transfer power balancing, including:

[0106] According to the power transfer balance control power, the target power of the second battery pack is controlled to be transferred to the vehicle battery, and the vehicle battery is controlled to transfer the target power to the first battery pack.

[0107] For example, the target power may be determined based on the power information difference between the battery packs, such as Figure 7 As shown, for example, if the power information of the first battery pack is 5% and the power information of the second battery pack is 6%, the target power can be determined as 0.5%, and through the DC-DC converter, 0.5% of the power of the second battery pack is first transferred to the vehicle charger (or 12V power supply), and then transferred to the first battery pack based on the vehicle charger to achieve energy balance.

[0108] It should be noted that the balancing control process may include at least one of charging balancing control, discharging balancing control and power transfer balancing control, and different balancing controls may be performed on different target batteries to be balanced based on balancing control parameters. For example, in the power transfer process, the action of transferring from the battery pack to the onboard charger and the action of transferring from the onboard charger to the battery pack may be performed simultaneously based on different interfaces, or the charging balancing process for low-energy battery packs and the discharging balancing process for high-energy battery packs among multiple target battery packs may also be performed simultaneously, ultimately achieving power balance between the battery packs.

[0109] In addition, the above balancing control methods are implemented based on the architecture of the existing power battery system of electric vehicles. For example, communication between each device or module can be implemented based on the CAN bus. During the balancing control process, the voltage, temperature and other information are collected by BIC at all times, and the DC-DC converter monitors the voltage, current and temperature at all times to ensure that the input power or output power corresponding to the battery pack is within the rated power of the battery pack during the balancing process. Since the balancing process is accompanied by energy transfer, the operating temperature of each module is ensured to be within the normal operating temperature range. Since the energy transfer process is accompanied by energy loss, the energy loss during the power balancing process is reduced by adapting the corresponding balancing control parameters to different working conditions and scenarios.

[0110] In some embodiments, after performing charge balancing control on the target battery pack according to the balancing control parameter to balance the charge between the battery packs, the method further includes:

[0111] For a battery pack in which power information difference exists between battery cells, power balancing control is performed on the battery cells to balance the power between the battery cells in the battery pack.

[0112] Exemplarily, each battery pack includes a plurality of battery cells connected in series. After the power between the battery packs is balanced, in order to ensure the consistency of the battery cells in the battery pack, the battery cells may be balanced based on the parallel resistance of each battery cell in the battery pack.

[0113] Through the embodiments of the present application, the corresponding balancing control parameters can be matched based on the power information difference between the battery packs, ensuring that the power between the battery packs can be quickly balanced without adding additional hardware configuration, improving the efficiency of battery balancing control, and meeting the needs of rapid battery balancing under more complex and special working conditions.

[0114] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0115] Corresponding to the battery balancing control method provided in the above embodiment, Fig.10 A schematic diagram of the structure of a battery balancing control device provided in an embodiment of the present application is shown. For the convenience of explanation, only the parts related to the embodiment of the present application are shown.

[0116] Reference Fig.11 , the battery balancing control device 11 comprises:

[0117] An acquisition module 111 is used to acquire power information corresponding to each battery pack;

[0118] The processing module 112 is used to determine the power information difference between each of the battery packs according to the power information of the battery packs; based on the power information difference and a preset power threshold, determine the target battery pack to be balanced among the battery packs, and the balancing control parameters corresponding to the target battery pack;

[0119] The balancing module 113 is used to perform power balancing control on the target battery pack according to the balancing control parameter to balance the power between the battery packs.

[0120] In a possible implementation, the power information includes voltage information and / or state of charge; the processing module 112 is further used to determine the power information difference between each of the battery packs based on the voltage information and / or state of charge of the battery pack.

[0121] In one possible implementation, the balancing control parameters include control power; the processing module 112 is also used to determine the target battery pack with the power information difference and the control power corresponding to the target battery pack when the power information difference is greater than the power threshold; wherein the control power is used to indicate the speed of power balancing control of the target battery pack.

[0122] In a possible implementation, the balancing control parameter includes a charging balancing control power; the balancing module 113 is further used to perform charging balancing control on the first battery pack according to the charging balancing control power when the power information of the first battery pack is less than the power information of the second battery pack, so that the power of the first battery pack is balanced with the second battery pack; wherein the first battery pack and the second battery pack are any two battery packs among the battery packs, and the first battery pack is the target battery pack to be balanced, and the power information difference between the first battery pack and the second battery pack meets the power threshold.

[0123] In a possible implementation, the balancing module 113 is further configured to perform charging balancing control on the first battery pack through a vehicle charger according to the charging balancing control power.

[0124] In a possible implementation, the balancing control parameter includes a discharge balancing control power; the balancing module 113 is further used to perform discharge balancing control on the second battery pack according to the discharge balancing control power when the power information of the first battery pack is less than the power information of the second battery pack, so that the power of the second battery pack is balanced with that of the first battery pack; wherein the first battery pack and the second battery pack are any two battery packs among the battery packs, and the second battery pack is the target battery pack to be balanced, and the difference in power information between the first battery pack and the second battery pack meets the power threshold.

[0125] In a possible implementation, the balancing module 113 is further configured to perform discharge balancing control on the second battery pack through a vehicle load according to the discharge balancing control power.

[0126] In a possible implementation, the balancing control parameters include a power transfer balancing control power; the balancing module 113 is also used to perform power transfer balancing control on the first battery pack and the second battery pack according to the power transfer balancing control power when the power information of the first battery pack is less than the power information of the second battery pack, so as to balance the power between the first battery pack and the second battery pack; wherein the first battery pack and the second battery pack are any two battery packs among the battery packs, and the first battery pack and the second battery pack are the target battery packs to be balanced, and the power information difference between the first battery pack and the second battery pack meets the power threshold.

[0127] In a possible implementation, the balancing module 113 is further used to balance the control power according to the power transfer, control the target power of the second battery pack to be transferred to the vehicle battery, and control the vehicle battery to transfer the target power to the first battery pack.

[0128] In a possible implementation, the balancing module 113 is also used to perform power balancing control on the battery cells of a battery pack in which there is a difference in power information between the battery cells, so as to balance the power between the battery cells in the battery pack; wherein each battery pack includes a plurality of battery cells.

[0129] The present application can match the corresponding balancing control parameters based on the power information difference between battery packs, ensuring that without adding additional hardware configuration, it can achieve rapid balancing control of the power between battery packs, improve the efficiency of battery balancing control, and meet the needs of rapid battery balancing under more complex and special working conditions.

[0130] Fig.12 A schematic diagram of the hardware structure of the balancing control system 12 is shown.

[0131] like Fig.12 As shown, the balancing control system 12 of this embodiment includes: at least one processor 120 ( Fig.12 Only one is shown in the figure), a memory 121, in which a computer program 122 that can be run on the processor 120 is stored. When the processor 120 executes the computer program 122, the steps in the above method embodiment are implemented, such as Figure 2 Alternatively, when the processor 120 executes the computer program 122, the functions of each module in the above device embodiment are realized.

[0132] It is understood that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the balancing control system 12. In other embodiments of the present application, the balancing control system 12 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0133] The balancing control system 12 may be a control system composed of a battery management system, a voltage converter, and an on-board charger or an on-board load in the entire vehicle architecture of the electric vehicle.

[0134] The balancing control system 12 may include, but is not limited to, a processor 120 and a memory 121. Those skilled in the art will appreciate that Fig.12 It is only an example of the balancing control system 12 and does not constitute a limitation of the balancing control system 12. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the server may also include an input sending device, a network access device, a bus, etc.

[0135] The processor 120 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0136] The processor 120 may also be provided with a memory for storing instructions and data. In some embodiments, the memory in the processor 120 is a cache memory. The memory may store instructions or data that the processor 120 has just used or cyclically used. If the processor 120 needs to use the instruction or data again, it may be directly called from the memory. This avoids repeated access, reduces the waiting time of the processor 120, and thus improves the efficiency of the system.

[0137] In some embodiments, the memory 121 may be an internal storage unit of the balanced control system 12, such as a hard disk or memory of the balanced control system 12. The memory 121 may also be an external storage device of the balanced control system 12, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the balanced control system 12. Further, the memory 121 may also include both an internal storage unit of the balanced control system 12 and an external storage device. The memory 121 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as program codes of computer programs. The memory 121 may also be used to temporarily store data that has been sent or is to be sent.

[0138] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0139] It should be noted that the structure of the above-mentioned electronic device is only illustrative, and based on different application scenarios, it may also include other physical structures, and the physical structure of the electronic device is not limited here.

[0140] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0141] like Fig.13 As shown, an embodiment of the present application further provides a power battery system, including the above-mentioned balancing control system 12 and at least two battery packs (battery pack 1 to battery pack n), wherein the balancing control system is used to control the power balancing of each of the battery packs.

[0142] An embodiment of the present application also provides an electric vehicle, comprising the above-mentioned power battery system.

[0143] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned method embodiments are implemented.

[0144] An embodiment of the present application provides a computer program product. When the computer program product runs on a server, the server implements the above-mentioned method embodiments when executing the server.

[0145] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable media may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0146] The algorithm development platform, electronic device, computer storage medium, and computer program product provided in the above-mentioned embodiments of the present application are all used to execute the methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects corresponding to the methods provided above, and will not be repeated here.

[0147] It should be understood that the above is only to help those skilled in the art to better understand the embodiments of the present application, rather than to limit the scope of the embodiments of the present application. According to the above examples given, those skilled in the art can obviously make various equivalent modifications or changes. For example, some steps in each embodiment of the above detection method may be unnecessary, or some steps may be newly added. Or a combination of any two or any multiple embodiments of the above. Such modifications, changes or combined schemes also fall within the scope of the embodiments of the present application.

[0148] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0149] It should be understood that the above is only to help those skilled in the art to better understand the embodiments of the present application, rather than to limit the scope of the embodiments of the present application. According to the above examples given, those skilled in the art can obviously make various equivalent modifications or changes. For example, some steps in each embodiment of the above detection method may be unnecessary, or some steps may be newly added. Or a combination of any two or any multiple embodiments of the above. Such modifications, changes or combined schemes also fall within the scope of the embodiments of the present application.

[0150] It should also be understood that the division of the methods, situations, categories and embodiments in the embodiments of the present application is only for the convenience of description and should not constitute a special limitation. The features of various methods, categories, situations and embodiments can be combined without contradiction.

[0151] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0152] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0153] In the embodiments provided in the present application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0154] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0155] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

[0156] Finally, it should be noted that the above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery balancing control method, characterized in that: The method comprises: Get the power information corresponding to each battery pack; Determining a power information difference between each of the battery packs according to the power information of the battery packs; Based on the power information difference and a preset power threshold, determining a target battery pack to be balanced among the battery packs, and a balancing control parameter corresponding to the target battery pack; The target battery pack is subjected to power balancing control according to the balancing control parameter, so that the power among the battery packs is balanced.

2. The method according to claim 1, characterized in that The power information includes voltage information and / or state of charge; and determining the power information difference between the battery packs according to the power information of the battery packs includes: The power information difference between the battery packs is determined according to the voltage information and / or the state of charge of the battery packs.

3. The method according to claim 1 or 2, characterized in that: The balancing control parameter includes control power; the target battery pack to be balanced in each of the battery packs is determined based on the power information difference and a preset power threshold, and the balancing control parameter corresponding to the target battery pack includes: In a case where the power information difference is greater than the power threshold, determining the target battery pack having the power information difference and the control power corresponding to the target battery pack; The control power is used to indicate the speed of performing power balancing control on the target battery pack.

4. The method according to claim 3, characterized in that The balancing control parameter includes a charging balancing control power; and performing charge balancing control on the target battery pack according to the balancing control parameter to balance the charge between the battery packs includes: When the power information of the first battery pack is less than the power information of the second battery pack, charging balancing control is performed on the first battery pack according to the charging balancing control power to balance the power between the first battery pack and the second battery pack; The first battery pack and the second battery pack are any two battery packs among the battery packs, and the first battery pack is the target battery pack to be balanced, and the power information difference between the first battery pack and the second battery pack meets the power threshold.

5. The method according to claim 4, characterized in that The performing charge balancing control on the first battery pack according to the charge balancing control power includes: According to the charge balancing control power, the first battery pack is charged balancingly controlled by a vehicle charger.

6. The method according to claim 3, characterized in that The balance control parameters include discharge balance control power; The performing power balancing control on the target battery pack according to the balancing control parameter to balance the power between the battery packs includes: When the power information of the first battery pack is less than the power information of the second battery pack, discharge balancing control is performed on the second battery pack according to the discharge balancing control power to balance the power of the second battery pack with that of the first battery pack; The first battery pack and the second battery pack are any two battery packs among the battery packs, and the second battery pack is the target battery pack to be balanced, and the power information difference between the first battery pack and the second battery pack meets the power threshold.

7. The method according to claim 6, characterized in that The performing discharge balancing control on the second battery pack according to the discharge balancing control power includes: According to the discharge balancing control power, discharge balancing control is performed on the second battery pack through the vehicle load.

8. The method according to claim 3, characterized in that The balancing control parameters include power transfer balancing control power; The performing power balancing control on the target battery pack according to the balancing control parameter to balance the power between the battery packs includes: When the power information of the first battery pack is less than the power information of the second battery pack, according to the power transfer balancing control power, power transfer balancing control is performed on the first battery pack and the second battery pack to balance the power between the first battery pack and the second battery pack; The first battery pack and the second battery pack are any two battery packs among the battery packs, and the first battery pack and the second battery pack are the target battery packs to be balanced, and the power information difference between the first battery pack and the second battery pack meets the power threshold.

9. The method according to claim 8, characterized in that The step of performing power transfer balancing control on the first battery pack and the second battery pack according to the power transfer balancing control power includes: According to the power transfer balancing control power, the target power of the second battery pack is controlled to be transferred to the vehicle battery, and the vehicle battery is controlled to transfer the target power to the first battery pack.

10. The method according to any one of claims 1 to 9, characterized in that: After performing charge balancing control on the target battery pack according to the balancing control parameter to balance the charge between the battery packs, the method further includes: For a battery pack in which each battery cell has a difference in power information, performing power balancing control on the battery cells to balance the power between each battery cell in the battery pack; Wherein, each of the battery packs includes a plurality of the battery cells.

11. A battery balancing control device, characterized in that: include: An acquisition module is used to obtain the power information corresponding to each battery pack; A processing module, configured to determine a power information difference between the battery packs according to the power information of each battery pack; Based on the power information difference and a preset power threshold, determining a target battery pack to be balanced among the battery packs, and a balancing control parameter corresponding to the target battery pack; The balancing module is used to perform power balancing control on the target battery pack according to the balancing control parameter to balance the power between the battery packs.

12. A balanced control system, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 10 when executing the computer program.

13. A power battery system, characterized in that: It comprises the balancing control system as claimed in claim 12 and at least two battery packs, wherein the balancing control system is used to control the power balancing of each of the battery packs.

14. An electric vehicle, characterized in that: Comprising the power battery system as claimed in claim 13.

15. 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 10 is implemented.

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