A BMS active equalization circuit

Abstract

This utility model discloses a BMS active balancing circuit, including: an isolated charging unit, a power transfer balancing unit, an AFE acquisition unit, and a control unit. The isolated charging unit is connected to the control unit and several cell groups, respectively. The power transfer balancing unit and the AFE acquisition unit are also connected to the control unit and several cell groups, respectively. The power transfer balancing unit includes several bidirectional DC-DC power units and a switch control module. The bidirectional DC-DC power units are connected to the switch control module and to the cell groups, respectively. The switch control module is connected to the control unit. By implementing the circuit of this utility model, the limitations of the prior art can be overcome, achieving power balancing between different cell groups within a single battery pack and even between different battery packs, thereby improving the stability and lifespan of the overall battery system.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a BMS active balancing circuit. Background Technology

[0002] During the manufacturing process of lithium batteries, due to the influence of production processes and material characteristics, key parameters such as internal resistance, remaining capacity, and open-circuit voltage will vary between different cells. These inconsistencies not only exist in the early stages of production but also intensify over time during battery use, leading to performance degradation. In particular, as the number of charge-discharge cycles increases, the voltage differences between individual cells become more pronounced, ultimately shortening the lifespan of the entire battery pack. To address this challenge, battery management systems integrate battery balancing functions, aiming to maintain the consistency of voltage among battery cells through power electronics technology, ensuring they are in a similar state during use and preventing overcharging or over-discharging.

[0003] Battery balancing technologies are mainly divided into two categories: passive and active. Passive balancing uses resistors to dissipate excess energy as heat, thereby reducing voltage; while active balancing uses charge transfer, that is, redistributing energy among different battery cells. This method has higher efficiency, lower energy loss, and faster balancing speed. However, traditional pairwise charge transfer balancing circuits are limited to achieving charge balancing within a specific cell group and cannot solve the problem of charge balancing between different cell groups within a single battery pack or across battery packs.

[0004] Therefore, it is necessary to design a new circuit to overcome the limitations of existing technology and achieve power balance between different cell groups within a single battery pack and even between different battery packs, thereby improving the stability and lifespan of the overall battery system. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a BMS active equalization circuit.

[0006] To solve the above-mentioned technical problems, the purpose of this utility model is achieved through the following technical solution: A BMS active balancing circuit is provided, comprising: an isolated charging unit, a power transfer balancing unit, an AFE acquisition unit, and a control unit. The isolated charging unit is connected to the control unit and several cell groups respectively. The power transfer balancing unit and the AFE acquisition unit are connected to the control unit and several cell groups respectively. The isolated charging unit provides a charging function, replenishing the cell groups with power through charging current. The power transfer balancing unit is used for power transfer between individual cells within the cell group, thereby achieving energy balance. The AFE acquisition unit collects voltage and temperature data of each individual cell within the cell group and feeds it back to the control unit. The control unit controls the balancing strategy of the cell group based on the voltage and temperature data collected by the AFE acquisition unit, determines the cells that need energy transfer, and controls the opening and closing of the balancing switch.

[0007] The power transfer equalization unit includes several bidirectional DC-DC power units and a switch control module. The bidirectional DC-DC power units are connected to the switch control module, the bidirectional DC-DC power units are connected to the battery pack, and the switch control module is connected to the control unit.

[0008] The further technical solution is as follows: the bidirectional DC-DC power unit includes BUCK and BOOST circuits.

[0009] The further technical solution is as follows: the isolated charging unit includes a power conversion unit and a charging control module; the charging control module is connected to the control unit; the charging control module is connected to the power conversion unit; and the power conversion unit is connected to the battery cell assembly.

[0010] The further technical solution is as follows: the charging control module includes a composite transistor QRM4.

[0011] The further technical solution is as follows: the power conversion unit includes a power chip U4 and a transformer T1, wherein the power chip U4 is connected to the composite transistor QRM4, the power chip U4 is connected to the transformer T1, and the transformer T1 is connected to the battery cell assembly.

[0012] The further technical solution is as follows: the switch control module includes a MOS transistor.

[0013] The further technical solution is as follows: each of the battery cell groups includes several battery cells; each of the bidirectional DC-DC power units is connected to two battery cells in the battery cell group.

[0014] A further technical solution is that each of the bidirectional DC-DC power units is interleaved with the cells in the cell group.

[0015] The further technical solution is as follows: the AFE acquisition unit includes a voltage acquisition module and a temperature acquisition module.

[0016] The advantages of this invention compared to existing technologies are as follows: By introducing an isolated charging unit, this invention can provide real-time charging to each cell within the battery pack, ensuring precise power balance during charging and discharging and preventing overcharging or over-discharging. The power transfer balancing unit, through a bidirectional DC-DC power unit and a switch control module, effectively achieves power transfer between different cells within the battery pack, optimizing the energy distribution of the battery pack and reducing energy waste. The AFE acquisition unit monitors the voltage and temperature data of each cell in real time, providing feedback information to the control unit to ensure stable battery operation under different environments. The control unit adjusts energy transfer based on voltage and temperature feedback data to achieve balanced energy management. This system not only achieves power balancing within a single battery pack but also coordinates energy distribution between different battery packs, thereby improving the overall stability and lifespan of the battery system.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic block diagram of a BMS active equalization circuit provided for an embodiment of this utility model;

[0020] Figure 2 This is a schematic diagram of the operation of a BMS active equalization circuit provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the operation of the power transfer equalization subunit provided in an embodiment of the present invention;

[0022] Figure 4 This is a detailed circuit diagram of the power transfer equalization subunit provided in an embodiment of the present invention;

[0023] Figure 5 This is a charging illustration in the power transfer equalization subunit provided in an embodiment of the present invention. Figure 1 ;

[0024] Figure 6 This is a charging illustration in the power transfer equalization subunit provided in an embodiment of the present invention. Figure 2 ;

[0025] Figure 7 This is a schematic diagram illustrating the specific principle of the isolated charging unit provided in an embodiment of the present invention;

[0026] Explanation of the markings in the image:

[0027] 10. Isolated charging unit; 20. Power transfer equalization unit; 30. AFE acquisition unit; 40. Control unit; 50. Isolated communication unit. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0029] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0030] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0032] During lithium battery manufacturing, differences in production processes and materials result in variations in parameters such as internal resistance, remaining capacity, and voltage between different cells. These differences intensify with usage time, impacting battery pack performance and lifespan. Battery management systems (BMS) integrate battery balancing functions to maintain consistent voltage across all battery cells, preventing overcharging or over-discharging. Battery balancing technology is divided into passive and active methods. Passive balancing reduces voltage by consuming excess energy, while active balancing improves efficiency and reduces energy loss through charge transfer. Traditional balancing circuits can only handle balancing within a single cell group and cannot address the issue of charge balancing across cell groups or battery packs.

[0033] Therefore, this utility model embodiment mentions a BMS active balancing circuit to overcome the limitations of the prior art, realize the power balance between different cell groups within a single battery pack and even between different battery packs, thereby improving the stability and lifespan of the overall battery system.

[0034] Specifically, this BMS active balancing circuit, by employing an isolated charging unit 10, a power transfer balancing unit 20, an AFE acquisition unit 30, and a control unit 40, overcomes the limitations of traditional balancing technologies and enables energy balancing between different cell groups. Through a bidirectional DC-DC power unit, power can be effectively transferred between different cells within a cell group, thereby preventing overcharging or over-discharging of certain cells and ensuring the stability of the battery system. The AFE acquisition unit 30 monitors battery voltage and temperature data in real time and feeds it back to the control unit 40 to optimize the balancing strategy and improve the overall accuracy of battery management. This system can perform balancing control on multiple battery packs and cell groups, thereby improving the efficiency and lifespan of the entire battery system. The charging unit's supplementary charging function further enhances the battery system's energy management capabilities.

[0035] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0036] Please see Figure 1An active balancing circuit for battery management systems (BMS) includes: an isolated charging unit 10, a power transfer balancing unit 20, an AFE (Active Energy Feedback) acquisition unit 30, and a control unit 40. The isolated charging unit 10 is connected to the control unit 40 and several battery cell groups. The power transfer balancing unit 20 and the AFE acquisition unit 30 are also connected to the control unit 40 and several battery cell groups. The isolated charging unit 10 provides a charging function by replenishing the battery cell groups with charging current. The power transfer balancing unit 20 is used for power transfer between individual cells within a battery cell group, thereby achieving energy balance. The AFE acquisition unit 30 collects voltage and temperature data of each individual cell within the battery cell group and feeds it back to the control unit 40. The control unit 40 controls the balancing strategy of the battery cell group based on the voltage and temperature data collected by the AFE acquisition unit 30, determines which cells need energy transfer, and controls the opening and closing of the balancing switch.

[0037] The power transfer equalization unit 20 includes several bidirectional DC-DC power units and a switching control module. The bidirectional DC-DC power units are connected to the switching control module and the battery cell assembly. The switching control module is connected to the control unit 40.

[0038] It should be noted that K N-cell sets can form a single battery pack with N*K cells. Here, K and N are integers. Each N-cell set can be connected to an isolated charging unit 10, a power transfer equalization unit 20, and an AFE acquisition unit 30.

[0039] In one embodiment, the aforementioned power transfer equalization unit 20 and AFE acquisition unit 30 are connected to the control unit 40 via an isolation communication unit 50, aiming to improve the system's safety and stability. Specifically, the isolation communication unit 50 isolates electrical signals between different modules within the battery management system, preventing potential electrical interference or malfunctions from affecting the normal operation of the entire system. Through this design, the power transfer equalization unit 20 and AFE acquisition unit 30 can safely and efficiently transmit data and provide control signal feedback to the control unit 40. Specifically, the power transfer equalization unit 20 receives equalization commands from the control unit 40 via the isolation communication unit 50 and executes power transfer between cells within the battery pack to achieve balanced battery pack management. The AFE acquisition unit 30 collects parameters such as voltage and temperature within the cell pack in real time and transmits them to the control unit 40 via the isolation communication unit 50, allowing the control unit to dynamically adjust the equalization strategy based on the current battery state. The introduction of the isolation communication unit 50 effectively prevents electrical interference in high-voltage environments, ensures the reliability of signal transmission, and improves the system's anti-interference capability and safety.

[0040] Specifically, the main function of the isolation charging unit 10 is to charge the battery cell assembly by supplementing current. The charging unit regulates the power balance between the various battery cell assemblies by controlling the current. By precisely controlling the amount of supplementary power, power balance between the battery cell assemblies can be achieved.

[0041] The power transfer and equalization unit 20, through its internal bidirectional DC-DC power unit and switching control module, is responsible for transferring power between different cells within the cell assembly. The bidirectional DC-DC power unit consists of BUCK and BOOST circuits, used to realize energy transfer between cells and ensure power balance within the cell assembly.

[0042] The AFE (Analog Front End) acquisition unit is used to collect real-time voltage and temperature data of each individual cell within the cell group. This data is fed back to the control unit 40, providing a basis for subsequent balancing decisions.

[0043] Based on the voltage and temperature information obtained from the AFE acquisition unit 30, the control unit 40 determines whether to perform energy transfer and controls the opening and closing of the equalization switch. Through a closed-loop feedback system, the control unit 40 ensures effective energy transfer between different cells in the entire BMS system, guaranteeing balanced operation of the battery pack.

[0044] The power transfer equalization unit 20 consists of several bidirectional DC-DC power units and a switching control module. Its working principle is as follows:

[0045] A bidirectional DC-DC converter enables energy transfer between battery cells. It combines BUCK and BOOST circuits to allow power to flow between different cells. Specifically, the power transfer equalization unit 20 connects two strings of battery cells via a bidirectional DC-DC power unit, thereby achieving bidirectional energy transfer.

[0046] The switch control module consists of multiple MOSFETs (such as Q1, Q2, Q3, etc.) to control the energy transfer between battery cells. During charging, the switch determines the direction of current flow according to the instructions of the control unit 40, thereby realizing energy transfer.

[0047] The AFE acquisition unit 30 monitors the voltage and temperature of each cell group in real time and transmits the acquired data to the control unit 40. The control unit 40 uses this data to determine which cells need to transfer power between them.

[0048] Based on the collected data, the control unit 40 determines whether to initiate the power transfer process. If energy transfer is required, the control unit 40 instructs the bidirectional DC-DC power unit in the power transfer equalization unit 20 to operate. The control unit 40 is also responsible for controlling the switch control module to ensure that power is transferred in the required direction and amount.

[0049] The isolated charging unit 10 provides additional charging functionality when necessary, ensuring the energy balance of the entire battery pack. The current of this unit is adjusted by the control unit 40 according to actual needs.

[0050] This circuit employs a closed-loop feedback control strategy, continuously adjusting the direction and magnitude of power transfer to ensure balanced power distribution among each cell within the battery pack. This approach effectively solves the imbalance problems within and between battery packs that traditional cell-to-cell power transfer methods cannot address.

[0051] This BMS active balancing circuit not only addresses the shortcomings of traditional cell balancing circuits but also provides a reliable and efficient solution through an innovative power transfer balancing mechanism. It is particularly suitable for large-scale battery pack systems, such as electric vehicles and energy storage devices. By precisely controlling the charging, balancing, and power transfer processes, this system can effectively extend battery life, improve energy utilization efficiency, and ensure that the battery pack remains balanced among its individual cells.

[0052] In one embodiment, the bidirectional DC-DC power unit described above includes BUCK and BOOST circuits.

[0053] The switching control module includes MOSFETs.

[0054] Specifically, please refer to Figure 4 The switching control module includes three MOSFETs: Q1, Q2, and Q3.

[0055] Please see Figures 5 to 6 When the upper battery cell B2 needs to charge the lower battery cell B1, the process is as follows: First, MOSFETs Q1 and Q2 are turned on (closed), while Q3 is turned off (open). At this time, battery B2 charges inductor L. Then, after inductor L has accumulated enough energy, the states are switched—MOSFET Q1 is turned off, Q2 remains on, and Q3 is turned on. At this time, inductor L begins to discharge to battery B1, completing one energy transfer cycle. By continuously repeating this process, energy transfer from battery B2 to battery B1 is achieved, such as... Figure 5 As shown.

[0056] Conversely, when the lower-level battery cell B0 intends to charge the upper-level battery cell B1, the operation sequence changes: MOSFETs Q3 and Q2 are first activated (closed), while Q1 remains inactive (open), allowing battery B0 to charge inductor L. Subsequently, after inductor L stores a certain amount of energy, MOSFET Q3 turns off, while ensuring that Q2 and Q1 remain closed, allowing inductor L to release the stored energy to battery B1. This process is repeated to achieve charging from battery B0 to battery B1. See details... Figure 6 .

[0057] for Figure 1 The system parameters described herein, where N represents the number of cells in each cell group, such as 12 or 16; and K refers to the number of cell groups, such as 4 groups or 6 groups. The current equalization system is designed to include two voltage regions: a high-voltage side and a low-voltage side. The high-voltage side mainly consists of an analog front-end acquisition module and an equalization module for transferring power between pairs of cells; the low-voltage side is mainly responsible for the control functions of the control unit 40.

[0058] Within a single battery pack, to meet the needs of data collection, it is typically divided into K independent cell groups, just as... Figure 1 As shown, each cell group contains N cells and is equipped with a corresponding equalization circuit and AFE acquisition circuit. Therefore, a complete battery pack will contain a total of N*K cells. For example, in a 24-cell battery pack configuration, it may be divided into 2 cell groups, each with 12 cells; while in a 72-cell battery pack, it may be divided into 6 cell groups, each with 12 cells.

[0059] The circuit provided in this embodiment solves the problem that traditional pairwise power transfer balancing circuits cannot achieve effective power balancing between different cell groups within a single battery pack, or even between different battery packs, thereby improving the overall performance and lifespan of the battery system.

[0060] In one embodiment, please refer to Figure 3 and Figure 7 The aforementioned isolated charging unit 10 includes a power conversion unit and a charging control module; the charging control module is connected to the control unit 40; the charging control module is connected to the power conversion unit; and the power conversion unit is connected to the battery cell assembly.

[0061] In one embodiment, please refer to Figure 7 The aforementioned charging control module includes a composite transistor QRM4.

[0062] In one embodiment, please refer to Figure 7 The aforementioned power conversion unit includes a power chip U4 and a transformer T1. The power chip U4 is connected to the composite transistor QRM4 and the transformer T1. The transformer T1 is connected to the battery cell assembly.

[0063] Specifically, the power conversion unit is responsible for converting the input voltage into an output voltage suitable for charging the battery pack. The power conversion unit includes a power chip U4 and a transformer T1. The power chip U4 regulates the voltage and ensures the charging safety and efficiency of the battery pack by controlling the current flow. The transformer T1 is used for voltage conversion, ensuring that the appropriate voltage is delivered to the battery cells.

[0064] The charging control module includes a composite transistor QRM4, which, through its connection with the power conversion unit, controls the charging current and the switching operation during the charging process. As a switching control element, the composite transistor QRM4 can precisely control the flow of power, ensuring balanced charging of the battery pack.

[0065] The charging control module ensures balanced charging of the battery cell pack by controlling the operation of the power conversion unit, preventing overcharging or over-discharging of the battery. Through the connection between the power conversion unit and the battery cell pack, energy transfer and balancing between different battery cell packs are achieved.

[0066] The power chip U4 and the composite transistor QRM4 work together to control the charging state of the battery pack. The power chip U4 provides a stable voltage source, while the composite transistor QRM4 adjusts the charging current according to the instructions of the MCU. After the power conversion unit completes the voltage conversion, the composite transistor QRM4 acts as a switching component, which can open or close the charging channel as needed, thereby precisely controlling the charging process of the battery pack.

[0067] The circuit in this embodiment employs a power transfer balancing subunit, which realizes energy transfer between battery cell groups through a bidirectional DC-DC power unit. After the charging unit is connected to the battery cell group, it can achieve balancing within the battery cell group and between different battery cell groups by controlling the power transfer between them.

[0068] The bidirectional DC-DC power unit (including BUCK and BOOST circuits) can efficiently transfer energy according to actual voltage and current requirements.

[0069] The switch control module controls the direction and magnitude of the current to ensure the orderly flow of energy between the battery cells.

[0070] The connection between the power conversion unit and the charging control module and the battery cell assembly is one of the core components. In this system, the coordinated operation of the power chip U4 and the composite transistor QRM4 ensures the efficiency and accuracy of the power conversion process. Transformer T1, as part of the power conversion, transfers voltage from the input terminal to the battery cell assembly, thereby ensuring that the battery pack's charging process meets requirements.

[0071] To accurately achieve battery balancing and charging, the AFE acquisition unit 30 collects battery voltage and temperature information and transmits it to the control unit 40. Based on real-time data, the control unit 40 determines whether to turn the charging unit and the power transfer balancing subunit on or off, ensuring that the battery pack is in the optimal charging state.

[0072] The isolated charging unit 10, through a precise power conversion and charging control module, combined with the cooperation of a bidirectional DC-DC power unit and a switching control module, can achieve balanced charging of multiple cell groups. This ensures that each cell group in the battery pack maintains a balanced charge under different operating conditions, thereby improving battery life and system efficiency. This BMS active balancing circuit design is suitable for large-scale battery pack applications, such as energy storage, automotive batteries, and marine batteries.

[0073] In this embodiment, each of the above-mentioned cell groups includes a plurality of cells; each bidirectional DC-DC power unit connects two cells within the cell group.

[0074] In this embodiment, each of the bidirectional DC-DC power units described above is interleaved with the cells within the cell group.

[0075] Each cell pack consists of several cells, which are typically connected in series to provide the required voltage. For example, a cell pack may contain four, six, or more cells. These cells are connected in series to form a battery pack. The voltage of each cell may vary, especially during charging and discharging, as the charge levels of different cells are often not exactly the same due to factors such as battery aging and internal inconsistencies.

[0076] To ensure the normal operation of the battery pack, the individual cells within each cell group need to maintain a certain voltage and charge balance to prevent premature degradation or damage to some cells due to excessive charge differences. The active balancing system adjusts the charge differences between the individual cells through energy transfer.

[0077] The function of the bidirectional DC-DC power unit is to realize energy transfer between the cells within the battery pack. Specifically, each bidirectional DC-DC power unit is composed of a BUCK and BOOST circuit, which can adjust the voltage under different operating conditions and realize energy exchange between the cells.

[0078] BUCK circuit: Transfers energy from higher-voltage cells to lower-voltage cells, achieving energy transfer at reduced voltage. This helps to transfer charge from high-voltage cells to low-voltage cells, thus achieving charge balance.

[0079] BOOST circuit: Conversely, the BOOST circuit is used to boost the charge of low-voltage cells to higher-voltage cells, thereby realizing energy transfer between cells and replenishing those with lower charge.

[0080] This bidirectional DC-DC power unit design enables energy transfer between battery cells, thereby achieving energy balance within the battery cell group.

[0081] In this embodiment, each bidirectional DC-DC power unit connects to two cells within the cell group, and these bidirectional DC-DC power units can connect to multiple cells in an interleaved manner. The purpose of this design is to enable each bidirectional DC-DC power unit to dynamically adjust the direction and amount of energy transfer according to the charge distribution of the cell group through a flexible connection method, thereby achieving a balance among multiple cells.

[0082] Interleaved connection refers to the connection of different bidirectional DC-DC power units to different cells within a cell group, enabling each bidirectional DC-DC power unit to transfer energy to cells within different cell groups. In some cases, a bidirectional DC-DC power unit can connect two adjacent cells and interleave multiple cells within a cell group as needed, allowing energy to flow within the cell group in the required direction and amount.

[0083] By interleaving the cells, energy flow between them can be controlled more flexibly. This not only allows for a rapid response to differences in cell voltage but also ensures more precise system balancing. For example, when the voltage of some cells is too high, energy can flow from the high-voltage cells to the low-voltage cells through multiple DC-DC units in an interleaved manner, ensuring that the voltage of each cell is within a reasonable range and avoiding battery damage caused by excessive differences in cell voltage.

[0084] The switching control module is responsible for controlling the energy transfer direction, balancing current magnitude, and balancing switch of each battery cell. Specifically, the switching control module achieves the following functions by controlling the switching state of each bidirectional DC-DC power unit:

[0085] Based on the control signals from the MCU, the switch control module can determine whether the power flows from one cell to another, or vice versa.

[0086] The switching control module can also control the output current of each bidirectional DC-DC power unit to ensure that the energy transfer speed between cells is moderate and does not cause the voltage of other cells to drop or rise excessively too quickly.

[0087] The switch control module is also responsible for turning the power transfer path on or off when needed, and adjusting the balancing strategy in a timely manner based on the feedback voltage and temperature information.

[0088] Through a closed-loop feedback system, the control unit 40 determines whether to enable or disable energy transfer based on voltage and temperature information received from the AFE acquisition unit 30. After each equalization operation, the system re-acquires cell voltage and temperature information to determine whether to continue equalization. This closed-loop control ensures the accuracy and reliability of energy equalization.

[0089] In this embodiment, each cell group consists of multiple cells, and each bidirectional DC-DC power unit connects to two cells within the cell group. Through staggered connections, multiple bidirectional DC-DC power units achieve energy transfer between cells, allowing each cell to receive appropriate charge and discharge regulation, thereby achieving balanced charge across the entire battery pack. The switch control module precisely controls the balancing direction, current magnitude, and switch state, working in conjunction with a closed-loop feedback system to ensure energy balance among the cells within the battery pack, guaranteeing the efficient and safe operation of the battery system.

[0090] In this embodiment, the AFE acquisition unit 30 includes a voltage acquisition module and a temperature acquisition module. The voltage acquisition module is responsible for monitoring the voltage of each cell in the battery pack in real time, ensuring that the battery pack maintains balance during charging and discharging, and avoiding unsafe situations caused by excessively high or low voltage. The temperature acquisition module monitors the temperature changes of the cells to prevent battery performance degradation or safety hazards caused by overheating. These two modules work together through precise data acquisition and feedback to provide real-time and accurate information to the battery management system, thereby effectively optimizing battery performance, extending battery life, and ensuring the safe operation of the battery pack.

[0091] The aforementioned BMS active balancing circuit, through the introduction of the isolated charging unit 10, can provide real-time charging to each cell within the battery pack, ensuring precise power balance during charging and discharging and preventing overcharging or over-discharging. The power transfer balancing unit 20, through a bidirectional DC-DC power unit and a switching control module, effectively realizes power transfer between different cells within the battery pack, optimizing the energy distribution of the battery pack and reducing energy waste. The AFE acquisition unit 30 monitors the voltage and temperature data of each cell in real time, providing feedback information to the control unit 40 to ensure stable battery operation under different environments. The control unit 40 adjusts energy transfer based on voltage and temperature feedback data to achieve balanced energy management. This system not only achieves power balancing within a single battery pack but also coordinates energy distribution between different battery packs, thereby improving the overall stability and lifespan of the battery system.

[0092] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A BMS active equalization circuit, characterized in that, include: The system comprises an isolated charging unit, a power transfer balancing unit, an AFE (Aspect-Enhanced Factor Transfer) acquisition unit, and a control unit. The isolated charging unit is connected to the control unit and several cell groups. The power transfer balancing unit and the AFE acquisition unit are also connected to the control unit and several cell groups. The isolated charging unit provides a charging function by replenishing the cell groups with charging current. The power transfer balancing unit is used for power transfer between cells within a cell group to achieve energy balance. The AFE acquisition unit collects voltage and temperature data of each individual cell within the cell group and feeds it back to the control unit. The control unit controls the balancing strategy of the cell group based on the voltage and temperature data collected by the AFE acquisition unit, determines which cells need energy transfer, and controls the opening and closing of the balancing switch. The power transfer equalization unit includes several bidirectional DC-DC power units and a switching control module. The bidirectional DC-DC power units are connected to the switching control module, the bidirectional DC-DC power units are connected to the battery cell assembly, and the switching control module is connected to the control unit. The isolated charging unit includes a power conversion unit and a charging control module; the charging control module is connected to the control unit; the charging control module is connected to the power conversion unit; the power conversion unit is connected to the battery cell assembly. Each of the battery cell groups includes a plurality of battery cells; each of the bidirectional DC-DC power units is connected to two battery cells within the battery cell group; Each of the bidirectional DC-DC power units is interleaved with the cells within the cell group.

2. The BMS active equalization circuit of claim 1, wherein, The bidirectional DC-DC power unit includes BUCK and BOOST circuits.

3. The BMS active equalization circuit of claim 1, wherein, The charging control module includes a composite transistor QRM4.

4. The BMS active equalization circuit of claim 3, wherein, The power conversion unit includes a power chip U4 and a transformer T1, wherein the power chip U4 is connected to the composite transistor QRM4 and the power chip U4 is connected to the transformer T1; the transformer T1 is connected to the battery cell assembly.

5. The BMS active equalization circuit of claim 1, wherein, The switch control module includes a MOSFET.

6. The BMS active equalization circuit of claim 1, wherein, The AFE acquisition unit includes a voltage acquisition module and a temperature acquisition module.

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