Battery equalization system, control method and device thereof, storage medium, and vehicle

Abstract

The application provides a battery equalization system, a control method and device thereof, a storage medium and a vehicle. The battery equalization system comprises at least two battery modules, a switch matrix and a voltage conversion module. Each battery module comprises a plurality of battery cells. The switch matrix is electrically connected with each battery module. The voltage conversion module is electrically connected with the switch matrix and is shared by the at least two battery modules. The switch matrix is selectively controlled, so that at least one battery cell of one of the at least two battery modules and at least one battery cell of another of the at least two battery modules are connected to the voltage conversion module for energy transfer, so as to equalize the voltage between the at least two battery modules. The application utilizes the switch matrix and the voltage conversion module for energy transfer instead of consumption, reduces energy waste, realizes energy utilization, improves equalization current, accelerates equalization speed, has low cost, simple structure and small size.

Description

Technical Field

[0001] This application relates to the field of battery balancing technology, and in particular to a battery balancing system, control method and apparatus, storage medium and vehicle. Background Technology

[0002] In electric vehicles and energy storage systems, battery module balancing technology is crucial for ensuring battery module performance and lifespan. Battery module balancing technologies include passive balancing and active balancing.

[0003] Passive balancing technology converts the energy of high-voltage cells into heat through equalizing resistor discharge, thereby achieving uniform voltage across all cells within a battery module. Passive balancing technology offers advantages such as low cost and a simple, reliable system, but it suffers from disadvantages including low balancing efficiency and slow balancing speed.

[0004] Active balancing technology transfers energy from high-voltage batteries to low-voltage batteries to achieve voltage consistency across all batteries within a battery module. Active balancing includes centralized and distributed balancing. Centralized balancing extracts energy from the entire battery pack and then replenishes the low-energy batteries using an energy conversion device. Converters or transformers are used for energy transfer. Distributed balancing involves placing energy storage components (such as inductors or capacitors) between adjacent batteries, allowing energy to flow between them. For example, an inductive method can be used, employing inductors and switching devices to achieve energy transfer. Active balancing technology is superior to passive balancing in efficiency and speed, but it is more expensive, has more complex circuitry, and requires more space. Summary of the Invention

[0005] This application provides an improved battery balancing system, control method and apparatus, storage medium, and vehicle.

[0006] This application provides a battery balancing system, including: At least two battery modules, each of which includes multiple battery cells; A switch matrix is ​​electrically connected to each of the battery modules; and, A voltage conversion module is electrically connected to the switch matrix and shared by the at least two battery modules; the switch matrix is ​​selectively controlled so that at least one cell of one of the at least two battery modules and at least one cell of the other of the at least two battery modules are respectively connected to and have their energy transferred through the voltage conversion module, so as to achieve voltage balance between the at least two battery modules.

[0007] The battery balancing system of this application embodiment uses a switch matrix and a shared voltage conversion module to transfer energy instead of consuming it, thereby reducing energy waste, improving energy utilization, increasing balancing current, accelerating balancing speed, and having low cost, simple structure, and small size.

[0008] In some embodiments, the switch matrix includes a cell switch group and an excitation switch group electrically connected to the cell switch group; the cell switch group is electrically connected to each of the plurality of cells in each battery module, and the excitation switch group is electrically connected to the voltage conversion module; wherein... When one of the cells in one battery module is charging and the other is discharging, the cell switching group and the excitation switching group are selectively controlled so that the discharging cell and the charging cell are voltage balanced through the voltage conversion module.

[0009] In some embodiments, energy transfer through charging and discharging can improve energy utilization and reduce energy waste.

[0010] In some embodiments, the plurality of cells includes a plurality of odd-numbered cells and a plurality of even-numbered cells; The cell switch group includes multiple cell selection switch groups and cell reversing switch groups. The multiple cell selection switch groups are electrically connected to the multiple cells of each battery module, and the cell reversing switch groups are electrically connected to the multiple cell selection switch groups and the excitation switch group. The cell selection switch group is used to select at least one odd-numbered cell or at least one even-numbered cell in each battery module that needs to participate in voltage equalization; the cell reversing switch group is used to switch the positive and negative terminals of the odd-numbered cells and the even-numbered cells.

[0011] In some embodiments, the charging and discharging of odd-numbered and even-numbered cells can be switched by using multiple cell selection switch groups and cell commutation switch groups in combination, thereby increasing the balancing current and accelerating the balancing speed.

[0012] In some embodiments, the switch matrix includes a cell switch group and an excitation switch group electrically connected to the cell switch group, wherein the excitation switch group is electrically connected to the voltage conversion module; The plurality of battery cells includes a plurality of odd-numbered battery cells and a plurality of even-numbered battery cells; The cell switch group includes multiple cell selection switch groups and cell reversing switch groups. The multiple cell selection switch groups are electrically connected to the multiple cells of each battery module, and the cell reversing switch groups are electrically connected to the multiple cell selection switch groups and the excitation switch group. The cell selection switch group is used to select at least one odd-numbered cell or at least one even-numbered cell in each battery module that needs to participate in voltage equalization; the cell reversing switch group is used to switch the positive and negative terminals of the odd-numbered cells and the even-numbered cells, so that the discharging cells and the charging cells can be voltage equalized through the excitation switch group and the voltage conversion module.

[0013] In some embodiments, by utilizing the cooperation between the cell commutation switch group and the cell selection switch group, bidirectional voltage balancing between cells in different modules can be achieved, enabling efficient energy utilization, improving balancing current and speed, and effectively simplifying the circuit structure and reducing the overall size and cost.

[0014] In some embodiments, the cell commutation switch group includes a first selection branch and a second selection branch; When at least one of the odd-numbered cells in one of the battery modules is charging or discharging, the cell selection switch group connected to the positive and negative terminals of the at least one odd-numbered cell is controlled to be turned on, and the first selection branch of the cell reversing switch group is controlled to be turned on, so that the at least one odd-numbered cell is connected to the voltage conversion circuit through the excitation switch group and performs voltage conversion through the voltage conversion module; When at least one of the even-numbered cells in one of the battery modules is charging or discharging, the cell selection switch group connected to the positive and negative terminals of the at least one even-numbered cell is controlled to be turned on, and the second selection branch of the cell reversing switch group is controlled to be turned on, so that the at least one even-numbered cell is connected to the voltage conversion circuit through the excitation switch group and undergoes voltage conversion through the voltage conversion module.

[0015] In some embodiments, voltage conversion between one or more odd-numbered cells and even-numbered cells can be achieved, thereby enabling simultaneous balancing of multiple cells and improving balancing efficiency.

[0016] In some embodiments, the positive terminals of the odd-numbered cells converge at a first connection point through a corresponding cell selection switch group, and the negative terminals of the odd-numbered cells converge at a second connection point through a corresponding cell selection switch group; when at least one of the odd-numbered cells of one of the battery modules is charging or discharging, the first connection point is the positive terminal convergence point, and the second connection point is the negative terminal convergence point; The positive terminals of the even-numbered cells converge at the second connection point through the corresponding cell selection switch group, and the negative terminals of the even-numbered cells converge at the first connection point through the corresponding cell selection switch group; when at least one of the even-numbered cells of one of the battery modules is charging or discharging, the second connection point is the positive terminal convergence point, and the first connection point is the negative terminal convergence point; The cell reversing switch group is used to switch the positive terminal junction and the negative terminal junction of the odd-numbered cells and the even-numbered cells by switching the first selection branch and the second selection branch.

[0017] In some embodiments, the positive and negative terminals of odd-numbered and even-numbered cells are switched by a cell reversing switch group to realize the charging and discharging of odd-numbered and even-numbered cells, improve the equalization current, and speed up the equalization speed.

[0018] In some embodiments, the voltage conversion module includes a primary side and a secondary side; the switching matrix includes an excitation switch group, which is electrically connected to the primary side and the secondary side respectively, and forms an excitation branch with the primary side and the secondary side; When one of the cells in one battery module is charging and the other is discharging, the excitation branch located on the same side as the discharging cell is called the discharge excitation branch, and the excitation branch located on the same side as the charging cell is called the charging excitation branch. The discharge excitation branch and the charging excitation branch transfer energy. The discharge excitation branch has the opposite current direction to the charging excitation branch.

[0019] In some embodiments, the excitation switch group cooperates with the primary and secondary sides of the voltage conversion module to form an excitation branch to achieve energy transfer, thereby improving energy utilization and reducing energy waste.

[0020] In some embodiments, the switch matrix includes multiple cell selection switch groups, cell commutation switch groups, and excitation switch groups; the battery balancing system further includes a front-end analog chip and a battery management chip, the multiple cell selection switch groups are integrated in the front-end analog chip, and the cell commutation switch groups, the excitation switch groups, and the voltage conversion module are all integrated in the battery management chip.

[0021] In some embodiments, multiple cell selection switch groups are integrated in the front-end analog chip, and cell commutation switch groups, excitation switch groups and voltage conversion modules are integrated in the battery management chip. This results in high integration, simple circuit structure, and reduced space and cost.

[0022] In some embodiments, the battery balancing system further includes a main control module and a switch control module, both of which are integrated within the battery management chip. The main control module is electrically connected to the switch control module and the front-end analog chip, and the switch control module is electrically connected to the cell commutation switch group and the excitation switch group. The main control module is used to control the on / off state of the cell commutation switch group and the excitation switch group by controlling the switch control module, and is also used to control the on / off state of the plurality of cell switch groups by controlling the front-end analog chip.

[0023] In some embodiments, the main control module and the switch control module are integrated within the battery management chip, resulting in high integration, simple circuit structure, and reduced space and cost.

[0024] In some embodiments, the battery balancing system further includes a data acquisition module integrated into the front-end analog chip and electrically connected to the plurality of cells of each battery module; the data acquisition module is used to acquire data from each of the cells.

[0025] In some embodiments, a data acquisition module is integrated into the front-end analog chip, which can collect data from each battery cell in real time. This method has high integration, simple circuit structure, and reduces space and cost.

[0026] In some embodiments, the at least two battery modules include two separately configured battery packs with different rated voltages, the two battery packs including a low-voltage battery pack and a high-voltage battery pack.

[0027] In some embodiments, energy is efficiently utilized and energy waste is avoided by transferring energy between high-voltage and low-voltage battery packs.

[0028] In some embodiments, the at least two battery modules include two modules with the same rated voltage and located in the same high-voltage battery.

[0029] In some embodiments, energy is transferred between different modules within the same high-voltage battery to achieve efficient energy utilization and avoid energy waste.

[0030] In some embodiments, when one of the cells in one battery module is charging and the other is discharging, the number of cells being discharged is the same as the number of cells being charged.

[0031] In some embodiments, the number of discharged cells is kept the same as the number of charged cells to balance energy transfer and ensure stability and reliability.

[0032] In some embodiments, the switch matrix includes a cell commutation switch group and an excitation switch group; the battery balancing system further includes a current sensor, which is electrically connected between the cell commutation switch group and the excitation switch group.

[0033] In some embodiments, by setting a current sensor for real-time current detection, high-precision detection and control can be achieved.

[0034] In some embodiments, the switch matrix includes a plurality of cell selection switch groups; each cell selection switch group includes a pair of back-to-back MOS switches.

[0035] In some embodiments, the on / off state of the battery cell is controlled by a pair of back-to-back MOS switches, which is highly sensitive, fast-responding, stable and reliable.

[0036] In some embodiments, the switch matrix includes a cell commutation switch group, which includes a full-bridge switch group or a MOS switch.

[0037] In some embodiments, the switching of the positive and negative terminals of the battery cell is achieved by a full-bridge switch group or a MOS switch, which is highly sensitive, fast-responding, stable and reliable.

[0038] In some embodiments, the switch matrix includes an excitation switch group, which includes a full-bridge switch group or MOS switches.

[0039] In some embodiments, the excitation branch is switched on and off by a full-bridge switch group or a MOS switch, which is highly sensitive, fast-responding, stable and reliable.

[0040] This application also provides a battery balancing control method, applied to a battery balancing system as described in any of the above embodiments; the battery balancing control method includes: Obtain the voltage of multiple cells from at least two battery modules; The voltage capacity that needs to be balanced is determined based on the difference between the voltage of each cell and the average voltage. Based on the required voltage capacity balancing, select the cells that need balancing, and determine at least one cell from one of the battery modules as the requester and at least one cell from the other battery module as the receiver; and, Voltage equalization is performed based on the determined voltages of the battery cells of the requesting party and the receiving party.

[0041] The battery balancing control method of this application embodiment is applied to the battery balancing system as described above to realize energy transfer, reduce energy waste, improve energy utilization, increase balancing current, and accelerate balancing speed.

[0042] In some embodiments, selecting cells to be balanced based on the required voltage capacity, to determine at least one cell from one battery module as the requester and at least one cell from another battery module as the receiver, includes: Based on the difference between the voltage of each cell and the average voltage, the cells with the maximum voltage and the cells with the minimum voltage are selected. Based on the difference between the maximum voltage and the average voltage, and the difference between the voltage of at least two cells adjacent to the cell having the maximum voltage and the average voltage, the cell having the maximum voltage is determined to be a single high-capacity cell. Based on the difference between the minimum voltage and the average voltage, and the difference between the voltage of at least two adjacent cells having the minimum voltage and the average voltage, the cell having the minimum voltage is determined to be a single low-capacity cell; and, The individual high-capacity battery cell and the individual low-capacity battery cell are identified, with one of them being the requester and the other being the receiver.

[0043] In some embodiments, the individual high-capacity voltage and the individual low-capacity voltage are determined by the cell voltage and the average voltage, thereby identifying the requester and the receiver. This allows for precise location of the cell to participate in the balancing process, resulting in high balancing accuracy and good balancing effect.

[0044] In some embodiments, selecting cells to be balanced based on the required voltage capacity, to determine at least one cell from one battery module as the requester and at least one cell from another battery module as the receiver, includes: Based on the difference between the voltage of each cell and the average voltage, the cells with the maximum voltage and the cells with the minimum voltage are selected. Based on the difference between the maximum voltage and the average voltage, and the difference between the voltage of the cell having the maximum voltage and the voltage of at least three consecutive cells and the average voltage, the at least three consecutive cells are determined to be a plurality of high-capacity cells. Based on the difference between the minimum voltage and the average voltage, and the difference between the voltage of the cell having the minimum voltage and the average voltage of at least three consecutive cells, the at least three consecutive cells are determined to be a plurality of low-capacity cells; and, The plurality of high-capacity battery cells and the plurality of low-capacity battery cells are identified, with one of them being the requester and the other being the receiver.

[0045] In some embodiments, multiple high-capacity voltages and multiple low-capacity voltages are determined by the cell voltage and average voltage, thereby identifying the requester and receiver. This allows for precise location of the cells required to participate in balancing and enables balancing of multiple cells with high balancing efficiency.

[0046] In some embodiments, the voltage equalization based on the determined voltages of the battery cells of the requesting party and the receiving party includes: When the voltage of one of the at least one battery cell that is the requesting party and the at least one battery cell that is the receiving party is higher than the average voltage, it is determined that the at least one battery cell is discharging; when the voltage of the other battery cell is lower than the average voltage, it is determined that the at least one battery cell is charging.

[0047] In some embodiments, the requester and receiver cells can select charging and discharging according to the actual voltage to achieve energy transfer, thereby realizing efficient energy utilization, avoiding energy waste, increasing balancing current, and accelerating balancing speed.

[0048] In some embodiments, the battery equalization control method further includes: In a non-charging scenario, voltage equalization begins when the voltage difference between the maximum voltage of one cell in one battery module and the minimum voltage of one cell in another battery module is greater than a first voltage threshold. In a charging scenario, voltage equalization begins when the voltage difference between the maximum voltage of one cell in one battery module and the minimum voltage of one cell in another battery module is greater than a second voltage threshold. Wherein, the first voltage threshold is greater than the second voltage threshold.

[0049] In some embodiments, voltage balancing can be performed in both charging and non-charging scenarios, and the power from the charging pile can be used to keep the battery module balanced, thus achieving simultaneous charging and balancing, thereby increasing the driving range of the battery module.

[0050] In some embodiments, the battery balancing control method further includes: stopping voltage balancing when the voltage capacity that the requesting party's cell needs to be balanced is 0, or when the voltage of the receiving party's cell reaches the average voltage.

[0051] In some embodiments, balancing is stopped when it is not needed, thus achieving on-demand balancing, reducing energy loss, and improving the overall efficiency of the system.

[0052] In some embodiments, the number of battery cells of the requesting party is the same as the number of battery cells of the receiving party.

[0053] In some embodiments, the number of battery cells in the requesting party is kept the same as the number of battery cells in the receiving party to ensure balanced and stable energy transfer.

[0054] This application also provides a computer storage medium storing a program thereon, which, when executed by a processor, implements the battery equalization control method as described in any of the above embodiments.

[0055] This application also provides a battery balancing control device, including: one or more processors, for implementing the battery balancing control method as described in any of the above embodiments.

[0056] This application also provides a vehicle including the battery balancing control device as described in the above embodiments. Attached Figure Description

[0057] Figure 1 The diagram shown is a schematic block diagram of one embodiment of the battery balancing system of this application.

[0058] Figure 2 As shown Figure 1 The diagram shows a schematic block diagram of another embodiment of the battery balancing system.

[0059] Figure 3 As shown Figure 1 The circuit diagram shown is for another embodiment of the battery equalization system.

[0060] Figure 4 As shown Figure 3 The diagram shows a partial circuit diagram of the current increase phase during the discharge of odd-numbered cells on the low-voltage side of the battery equalization system.

[0061] Figure 5 As shown Figure 3 The diagram shows a partial circuit diagram of the current reduction phase during the discharge of odd-numbered cells on the low-voltage side of the battery balancing system.

[0062] Figure 6 As shown Figure 3 The diagram shows a partial circuit diagram of the low-voltage side odd-numbered cells being charged in the battery balancing system.

[0063] Figure 7 As shown Figure 3 The diagram shows a partial circuit diagram of the current increase phase during the discharge of even-numbered cells on the low-voltage side of the battery equalization system.

[0064] Figure 8 As shown Figure 3 The diagram shows a partial circuit diagram of the low-voltage side even-numbered cells in the battery equalization system during the current reduction phase of discharge.

[0065] Figure 9 As shown Figure 3The diagram shows a partial circuit diagram of the low-voltage side odd-numbered cells discharging and charging in the battery balancing system.

[0066] Figure 10 As shown Figure 3 The circuit diagram shown is a partial circuit diagram of the discharge of odd-numbered cells on the high-voltage side of the battery balancing system.

[0067] Figure 11 As shown Figure 3 The circuit diagram shown illustrates the discharge of odd-numbered cells on the high-voltage side of the battery balancing system.

[0068] Figure 12 As shown Figure 3 The circuit diagram of the voltage conversion module of the battery equalization system.

[0069] Figure 13 As shown Figure 3 A circuit diagram of another embodiment of the battery balancing system 1 shown.

[0070] Figure 14 The diagram shown is a flowchart of one embodiment of the battery equalization control method of this application.

[0071] Figure 15 As shown Figure 14 A schematic diagram of a single high-capacity cell identified in the battery balancing control method shown.

[0072] Figure 16 As shown Figure 14 A schematic diagram of a single low-capacity cell identified in the battery balancing control method shown.

[0073] Figure 17 As shown Figure 14 A schematic diagram of multiple high-capacity cells identified in the battery balancing control method shown.

[0074] Figure 18 As shown Figure 14 A schematic diagram of multiple low-capacity cells identified in the battery balancing control method shown.

[0075] Figure 19 The diagram shown is a structural block diagram of one embodiment of the battery balancing control device of this application. Detailed Implementation

[0076] The battery balancing system, control method and apparatus, storage medium and vehicle of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0077] Figure 1 The diagram shown is a schematic block diagram of one embodiment of the battery balancing system 1 of this application. Figure 1As shown, the battery balancing system 1 includes at least two battery modules 10, a switch matrix 20, and a voltage conversion module 30. One of the at least two battery modules 10 is a low-voltage side battery module, and the other battery module 10 is a high-voltage side battery module. Figure 1 In the illustrated embodiment, the battery module 10 on the left is the low-voltage side battery module, and the battery module 10 on the right is the high-voltage side battery module. The low-voltage side battery module 10 is electrically connected to the low-voltage load 101 and the external output switch 102, while the high-voltage side battery module is electrically connected to the high-voltage load 103. The low-voltage load 101 can be a 12V low-voltage load for the entire vehicle. The high-voltage load 103 can be a high-voltage load for the entire vehicle, such as a drive motor, high-voltage air conditioning, or other high-voltage components.

[0078] exist Figure 1 In the illustrated embodiment, each battery module 10 includes multiple battery cells 11. A switch matrix 20 is electrically connected to each battery module 10. The switch matrix 20 is electrically connected to each battery cell 11 of each battery module 10. A voltage conversion module 30 is electrically connected to the switch matrix 20 and is shared by at least two battery modules. The voltage conversion module 30 may be a DC-DC converter for voltage conversion and energy transfer between different battery cells. The switch matrix 20 is selectively controlled so that at least one battery cell 11 of one of the at least two battery modules 10 and at least one battery cell 11 of the other of the at least two battery modules 10 are respectively connected to and have their energy transferred through the voltage conversion module 30, thereby achieving voltage equalization between the at least two battery modules 10. When the switch matrix 20 is selectively controlled to be turned on, the cells 11 of the battery module 10 on the left and the cells 11 of the battery module 10 on the right are voltage-converted through a shared voltage conversion module 30 to balance the voltage of the cells 11 in the battery modules 10 on both sides. In some embodiments, when one of the cells 11 in the low-voltage side battery module 10 is discharging, one of the cells 11 in the high-voltage side battery module 10 is charging. In other embodiments, when one of the cells 11 in the high-voltage side battery module 10 is discharging, one of the cells 11 in the low-voltage side battery module 10 is charging.

[0079] The battery balancing system 1 of this application embodiment uses a switch matrix 20 and a shared voltage conversion module 30 to transfer energy instead of consuming it, thereby reducing energy waste, achieving energy utilization efficiency, increasing balancing current, accelerating balancing speed, and having low cost, simple structure, and small size.

[0080] exist Figure 1In the illustrated embodiment, when one of the cells 11 in one battery module 10 is charging while the other is discharging, the number of discharging cells 11 is the same as the number of charging cells 11. In some embodiments, when one or more cells 11 in the low-voltage side battery module 10 are discharging, one or more cells 11 in the high-voltage side battery module 10 are charging. In other embodiments, when one or more cells 11 in the high-voltage side battery module 10 are discharging, one or more cells 11 in the low-voltage side battery module 10 are charging, thus achieving energy transfer. To maintain energy transfer balance, the number of discharging cells 11 is kept consistent with the number of charging cells 11. This configuration ensures that the number of discharging cells 11 is the same as the number of charging cells 11, resulting in balanced, stable, and reliable energy transfer.

[0081] Figure 2 As shown Figure 1 A schematic block diagram of another embodiment of the battery balancing system 1 is shown. (In conjunction with...) Figure 1 and Figure 2 As shown, the switch matrix 20 includes a cell switch group 21 and an excitation switch group 22 electrically connected to the cell switch group 21. The cell switch group 21 is electrically connected to multiple cells 11 of each battery module 10, and the excitation switch group 22 is electrically connected to the voltage conversion module 30. When one cell 11 of one battery module 10 is charging while the other is discharging, the cell switch group 21 and the excitation switch group 22 are selectively controlled to equalize the voltage of the discharging and charging cells through the voltage conversion module 30. In some embodiments, when the cell switch group 21 and the excitation switch group 22 are selectively controlled to be turned on, one or more cells 11 of the low-voltage side battery module 10 discharge while one or more cells 11 of the high-voltage side battery module 10 charge, thus achieving voltage equalization through the voltage conversion module 30. In other embodiments, when the cell switch group 21 and the excitation switch group 22 are selectively controlled to be turned on, one or more cells 11 of the high-voltage side battery module 10 discharge while one or more cells 11 of the low-voltage side battery module 10 charge, thus achieving voltage equalization through the voltage conversion module 30. Energy transfer through charging and discharging improves energy utilization and reduces energy waste.

[0082] exist Figure 2In the illustrated embodiment, the plurality of battery cells 11 includes a plurality of odd-numbered battery cells 111 and a plurality of even-numbered battery cells 112. The plurality of battery cells 11 includes 1, 2, 3, 4, ..., n. Among them, the plurality of odd-numbered battery cells 111 is 1, 3, 5, ..., n-1, and the plurality of even-numbered battery cells 112 is 2, 4, 6, ..., n. Figure 2 In the battery module 10 on the low-voltage side, there are two odd-numbered cells 111 and two even-numbered cells 112. On the high-voltage side, there are three odd-numbered cells 111 and three even-numbered cells 112. However, it is not limited to this.

[0083] exist Figure 2 In the illustrated embodiment, the cell switch group 21 includes multiple cell selection switch groups 23 and a cell reversing switch group 24. The multiple cell selection switch groups 23 are electrically connected to corresponding multiple cells 11 of each battery module 10. The cell reversing switch group 24 is electrically connected to the multiple cell selection switch groups 23 and the excitation switch group 22. Specifically, the cell selection switch groups 23 are used to select at least one odd-numbered cell 111 or at least one even-numbered cell 112 in each battery module 10 that needs to participate in voltage equalization. The cell selection switch groups 23 are mainly used to control the on / off state of at least one odd-numbered cell 111 or at least one even-numbered cell 112. The cell reversing switch group 24 is used to switch the positive and negative terminals of the odd-numbered cells 111 and even-numbered cells 112, allowing the discharging cells and charging cells to undergo voltage equalization through the excitation switch group 22 and the voltage conversion module 30. The cell reversing switch group 24 is mainly used to control the positive and negative terminals of the odd-numbered cells 111 and even-numbered cells 112. In other words, the positive and negative terminals of odd-numbered cells 111 and even-numbered cells 112 can be switched using the same cell commutation switch group 24. By cooperating with multiple cell selection switch groups 23 and cell commutation switch groups 24, the charging and discharging of odd-numbered cells 111 and even-numbered cells 112 can be switched, increasing the balancing current and accelerating the balancing speed. Furthermore, by utilizing the cooperation between the cell selection switch groups 23 and cell commutation switch groups 24, bidirectional voltage balancing between cells in different modules can be achieved, enabling efficient energy utilization, improving balancing current and speed, while effectively simplifying the circuit structure and reducing the overall size and cost.

[0084] exist Figure 2In the described embodiment, the battery balancing system 1 further includes a front-end analog chip 104 and a battery management chip 105. The front-end analog chip 104 and the battery management chip 105 communicate via a daisy-chain. Multiple cell selection switch groups 23 are integrated within the front-end analog chip 104, while cell commutation switch groups 24, excitation switch groups 22, and voltage conversion modules 30 are all integrated within the battery management chip 105. Integrating multiple cell selection switch groups 23 within the front-end analog chip 104 and integrating the cell commutation switch groups 24, excitation switch groups 22, and voltage conversion modules 30 within the battery management chip 105 results in high integration, a simple circuit structure, and reduced space and cost.

[0085] exist Figure 2 In the illustrated embodiment, the battery balancing system 1 further includes a main control module 40 and a switch control module 50, both integrated within the battery management chip 105. The main control module 40 is electrically connected to the switch control module 50 and the front-end analog chip 104. The switch control module 50 is also electrically connected to the cell commutation switch group 24 and the excitation switch group 22. The main control module 40 controls the on / off state of the cell commutation switch group 24 and the excitation switch group 22 via the control switch control module 50, and controls the on / off state of multiple cell switch groups 21 via the control front-end analog chip 104. The main control module 40 performs functions such as SOX calculation, fault diagnosis, vehicle communication, and balancing strategies. The switch control module 50 controls the on / off state of the wake-up cell commutation switch group 24 and the excitation switch group 22. The multiple cell selection switch groups 23 and control commands on the front-end analog chip 104 are sent to the front-end analog chip 104 by the main control module 40 of the battery management chip 105, causing the corresponding cell selection switch groups 23 to execute. The main control module 40 and the switch control module 50 are integrated in the battery management chip 105, resulting in high integration, simple circuit structure, and reduced space and cost.

[0086] exist Figure 2 In the illustrated embodiment, the battery balancing system 1 further includes a data acquisition module 60, integrated into the front-end analog chip 104 and electrically connected to multiple battery cells 11 in each battery module 10. The data acquisition module 60 is used to acquire data from each battery cell 11. A cell selection switch group 23 is located within the front-end analog chip 104. The front-end analog chip 104 also has a data acquisition function, acquiring variables such as voltage and temperature of the battery cells. Integrating the data acquisition module 60 within the front-end analog chip 104 allows for real-time acquisition of data from each battery cell 11, resulting in high integration, a simple circuit structure, and reduced space and cost.

[0087] Figure 3 As shown Figure 1 The circuit diagram shows another embodiment of the battery balancing system 1. Combined with... Figures 1 to 3As shown in the embodiment, at least two battery modules 10 include two separately configured battery packs with different rated voltages. The two battery packs include a low-voltage battery pack and a high-voltage battery pack. In this embodiment, the low-voltage side battery module 10 can be a 12V small battery pack. The high-voltage side battery module is the vehicle's high-voltage battery pack. By transferring energy between the high-voltage battery pack and the low-voltage battery pack (12V small battery pack), efficient energy utilization is achieved, and energy waste is avoided.

[0088] exist Figure 3 In the illustrated embodiment, the cell reversing switch group 24 includes a first selection branch 241 and a second selection branch 242. The cell reversing switch group 24 switches between the first selection branch 241 and the second selection branch 242 to select whether to connect an odd number of cells 111 or an even number of cells 112.

[0089] exist Figure 3 In the illustrated embodiment, when at least one odd-numbered cell 111 of one of the battery modules 10 is charging or discharging, the cell selection switch group 23 connected to the positive and negative terminals of the at least one odd-numbered cell 111 is controlled to be turned on, and the first selection branch 241 of the cell commutation switch group 24 is controlled to be turned on, so that the at least one odd-numbered cell 111 is connected to the voltage conversion circuit through the excitation switch group 22, and voltage conversion is performed through the voltage conversion module 30. When the cell commutation switch group 24 switches to the first selection branch 241, at least one odd-numbered cell 111 is connected to the circuit to participate in voltage equalization. Here, voltage equalization can be either charging or discharging.

[0090] exist Figure 3 In the illustrated embodiment, when at least one even-numbered cell 112 of one of the battery modules 10 is charging or discharging, the cell selection switch group 23 connected to the positive and negative terminals of the at least one even-numbered cell 112 is controlled to be turned on, and the second selection branch 242 of the cell commutation switch group 24 is controlled to be turned on, so that the at least one even-numbered cell 112 is connected to the voltage conversion circuit through the excitation switch group 22, and voltage conversion is performed through the voltage conversion module 30. When the cell commutation switch group 24 switches to the second selection branch 242, at least one even-numbered cell 112 is connected to the circuit to participate in voltage equalization. Here, voltage equalization can be either charging or discharging.

[0091] With this configuration, the voltage conversion between one or more odd-numbered cells 111 and even-numbered cells 112 can be achieved through the coordinated use of the cell selection switch group 23, the cell reversing switch group 24 and the excitation switch group 22. This enables simultaneous balancing of multiple cells 11 and improves balancing efficiency.

[0092] exist Figure 3In the illustrated embodiment, the positive terminals of the odd-numbered cells 111 converge at a first connection point A via corresponding cell selection switch groups 23, and the negative terminals of the odd-numbered cells 111 converge at a second connection point B via corresponding cell selection switch groups 23. When at least one odd-numbered cell 111 of one of the battery modules 10 is charging or discharging, the first connection point A is the positive terminal convergence point, and the second connection point B is the negative terminal convergence point. In some embodiments, when at least one odd-numbered cell 111 of the low-voltage side battery module 10 is charging or discharging, the first connection point A is the positive terminal convergence point, and the second connection point B is the negative terminal convergence point. In other embodiments, when at least one odd-numbered cell 111 of the high-voltage side battery module 10 is charging or discharging, the first connection point A is the positive terminal convergence point, and the second connection point B is the negative terminal convergence point.

[0093] exist Figure 3 In the illustrated embodiment, the positive terminals of the even-numbered cells 112 converge at the second connection point B via the corresponding cell selection switch group 23, and the negative terminals of the even-numbered cells 112 converge at the first connection point A via the corresponding cell selection switch group 23. When at least one even-numbered cell 112 of one of the battery modules 10 is charging or discharging, the second connection point B is the positive terminal convergence point, and the first connection point A is the negative terminal convergence point. In some embodiments, when at least one even-numbered cell 112 of the low-voltage side battery module 10 is charging or discharging, the second connection point B is the positive terminal convergence point, and the first connection point A is the negative terminal convergence point. In other embodiments, when at least one even-numbered cell 112 of the high-voltage side battery module 10 is charging or discharging, the second connection point B is the positive terminal convergence point, and the first connection point A is the negative terminal convergence point.

[0094] exist Figure 3 In the illustrated embodiment, the cell reversing switch assembly 24 can switch the positive and negative terminals of the first connection point A and the second connection point B. That is, the first connection point A can be the positive terminal of an odd-numbered cell, and the second connection point B can be the negative terminal of an odd-numbered cell. Alternatively, the first connection point A can be the negative terminal of an even-numbered cell, and the second connection point B can be the positive terminal of an even-numbered cell.

[0095] exist Figure 3In the illustrated embodiment, the cell reversing switch group 24 is used to switch the positive and negative junction points of odd-numbered cells 111 and even-numbered cells 112 by switching the first selection branch 241 and the second selection branch 242. In some embodiments, when the cell reversing switch group 24 switches to the first selection branch 241, the first selection branch 241 is electrically connected to the first connection point A of the positive junction point and the second connection point B of the negative junction point, so that at least one odd-numbered cell 111 on the low-voltage side or the high-voltage side is charged or discharged. In other embodiments, when the cell reversing switch group 24 switches to the second selection branch 242, the second selection branch 242 is electrically connected to the second connection point B of the positive junction point and the first connection point A of the negative junction point, so that at least one even-numbered cell 112 on the low-voltage side or the high-voltage side is charged or discharged.

[0096] With this configuration, the positive and negative terminals of odd-numbered cells 111 and even-numbered cells 112 are switched by the cell reversing switch group 24, thereby realizing the charging and discharging of odd-numbered cells 111 and even-numbered cells 112, improving the equalization current and accelerating the equalization speed.

[0097] exist Figure 3 In the illustrated embodiment, the voltage conversion module 30 includes a primary side 301 and a secondary side 302. The excitation switch group 22 is electrically connected to both the primary side 301 and the secondary side 302, forming an excitation branch with them. When one of the cells 11 in one battery module 10 is charging while the other is discharging, the excitation branch on the same side as the discharging cell 11 is called the discharge excitation branch, and the excitation branch on the same side as the charging cell 11 is called the charging excitation branch. Energy transfer occurs between the discharge excitation branch and the charging excitation branch. The current directions of the discharge excitation branch and the charging excitation branch are opposite. In this embodiment, the current in the discharge excitation branch gradually increases from small to large. When the current in the discharge excitation branch remains stable and the rate of change of the current decreases to a threshold value, the current in the discharge excitation branch gradually decreases; the current in the charging excitation branch gradually increases from small to large. The excitation switch group 22 is combined with the primary side 301 and the secondary side 302 of the voltage conversion module 30 to form an excitation branch, so as to realize energy transfer, improve energy utilization and reduce energy waste.

[0098] exist Figure 3 In the illustrated embodiment, the battery balancing system 1 further includes a current sensor 70, which is electrically connected between the cell commutation switch group 24 and the excitation switch group 22. By providing the current sensor 70 for real-time current detection, high-precision detection and control can be achieved. Figure 3In the illustrated embodiment, each cell selection switch group 23 includes a pair of back-to-back MOS switches. Controlling the on / off state of the cell 11 via a pair of back-to-back MOS switches provides high sensitivity, fast response, and stable reliability. Figure 3 In the illustrated embodiment, the cell commutation switch group 24 includes a full-bridge switch group or MOSFET switches. Switching between the positive and negative terminals of the cell 11 is achieved through the full-bridge switch group or MOSFET switches, offering high sensitivity, fast response, and stable reliability. Figure 3 In the illustrated embodiment, the excitation switch group 22 includes a full-bridge switch group or MOS switches. The current in the excitation branch is switched on and off using the full-bridge switch group or MOS switches, resulting in high sensitivity, fast response, and stable reliability. Figure 3 In the illustrated embodiment, the excitation switch group 22 can be a full-bridge switch group or a MOS switch, which are different in principle but both serve to generate alternating current to realize the change of magnetic field in the voltage conversion module 30. The two can be interchanged, or the same components can be used on both sides.

[0099] Figure 4 As shown Figure 3 The circuit diagram shown is a partial circuit diagram of the current increase stage of the discharge of odd-numbered cells 111 on the low-voltage side of the battery equalization system 1. Figure 5 As shown Figure 3 The circuit diagram shown is a partial circuit diagram of the current reduction stage of the low-voltage side odd-numbered cells 111 of the battery equalization system 1. Figure 4 and Figure 5 The diagram shows the discharge process of odd-numbered cell 111.

[0100] Combination Figure 4 and Figure 5 As shown, suppose that the voltage of a certain odd-numbered cell 111 is higher than the voltage of other cells and needs to be discharged.

[0101] Taking the first odd-numbered cell 111 that needs to be discharged as an example, the direction of current flow is shown by the arrow in Figure 4. In the cell selection switch group 23, the two back-to-back MOS switches 23-1 and 23-2 connected to the cell 11 that needs to be discharged are turned on. The excitation switch group 22 is a full-bridge switch group. Switches 22-1 and 22-4 of the full-bridge switch group are turned on. The first selection branch 241 of the cell commutation switch group 24 is turned on, that is, switches 24-1 and 24-4 of the cell commutation switch group 24 are turned on.

[0102] Figure 4In the illustrated embodiment, when the first odd-numbered cell 111 discharges, the two back-to-back MOS switches 23-1 and 23-2 connected to the cell 11 to be discharged in the cell selection switch group 23 are turned on. The current flow direction is as shown by the arrow in Figure 6, flowing through the back-to-back MOS switch 23-1, the first connection point A, the switch 24-1 in the cell commutation switch group 24, the switch 22-1 in the excitation switch group 22, point E, point F, the switch 22-4 in the excitation switch group 22, the switch 24-4 in the cell commutation switch group 24, the second connection point B, and the back-to-back MOS switch 23-2. This achieves the discharge of the first odd-numbered cell 111. At this time, the current flows from point E to point F through the primary side 301 of the voltage conversion module 30. The current direction in the discharge excitation branch is from top to bottom (from point E to point F), and the current magnitude gradually increases.

[0103] Because the inductor coil of voltage conversion module 30 has the characteristic of passing DC and blocking AC, the resistance of the inductor coil of the primary side 301 of voltage conversion module 30 can be ignored when the current change gradually stabilizes. Therefore, when the current magnitude of the discharge excitation branch remains stable and the rate of change of the current decreases to the rate of change threshold, the switch 22-4 of the excitation switch group 22 is turned off. The current direction will flow along the loop from point E, point F, switch 22-3, switch 22-1, and then back to point E (e.g., ...). Figure 5 As shown in the diagram, the current gradually decreases. With this configuration, the excitation switch group 22 and the primary side 301 of the voltage conversion module 30 cooperate to form an excitation branch, and energy transfer is achieved through discharge, which can improve energy utilization and reduce energy waste.

[0104] Figure 6 As shown Figure 3 The circuit diagram shown is a partial circuit diagram of the charging of odd-numbered cells 111 on the low-voltage side of the battery equalization system 1. Figure 6 The diagram shows the charging process of odd-numbered battery cell 111. Figure 6 In the illustrated embodiment, assuming that the voltage of a certain odd-numbered cell 111 is lower than the voltage of the other cells and needs to be charged, the charging is performed using the electrical energy coupled from the voltage conversion module 30. Taking the first odd-numbered cell 111 needing charging as an example, the current flow direction is as follows... Figure 6 The arrows in the diagram indicate the direction of the current coupled through the voltage conversion module 30, which flows from F to E.

[0105] exist Figure 6In the illustrated embodiment, when the first odd-numbered cell 111 is charging, the two back-to-back MOS switches 23-1 and 23-2 connected to the cell 11 to be charged in the cell selection switch group 23 are turned on. Current flows through the back-to-back MOS switch 23-2, the second connection point B, the switch 24-4 in the cell commutation switch group 24, the switch 22-4 in the excitation switch group 22, point F, point E, the switch 22-1 in the excitation switch group 22, the switch 24-1 in the cell commutation switch group 24, the first connection point A, and the back-to-back MOS switch 23-1. This achieves the charging of the first odd-numbered cell 111. The direction of the charging current for the odd-numbered cell 111 is opposite to the direction of the discharging current for the odd-numbered cell 111. With this configuration, the excitation switch group 22 and the primary side 301 of the voltage conversion module 30 cooperate to form an excitation branch, achieving energy transfer through charging, which can improve energy utilization and reduce energy waste.

[0106] Figure 7 As shown Figure 3 The circuit diagram shown is a partial circuit diagram of the current increase stage of the discharge of even-numbered cells 112 on the low-voltage side of the battery equalization system 1. Figure 8 As shown Figure 3 The circuit diagram shown is a partial circuit diagram of the current reduction stage of the even-numbered cells 112 on the low-voltage side of the battery equalization system 1. Figure 7 and Figure 8 The embodiment shown illustrates the discharge process of an even number of cells 112. Figures 7 to 8 The illustrated embodiments and Figures 4 to 5 Compared to the illustrated embodiment, the discharge process of even-numbered cells 112 is similar to that of odd-numbered cells 111, and the current flow direction of even-numbered cells 112 is basically the same as that of odd-numbered cells 111. The main difference is that the second selection branch 242 of the cell commutation switch group 24 is turned on, that is, the switching transistors 24-2 and 24-3 of the cell commutation switch group 24 are turned on. Through the switching transistors 24-2 and 24-3 in the cell commutation switch group 24, the current discharged from even-numbered cells 112 is commutated.

[0107] exist Figure 7 and Figure 8 In the illustrated embodiment, when the first even-numbered cell 112 discharges, the two back-to-back MOS switches 23-2 and 23-3 connected to the cell 11 to be discharged in the cell selection switch group 23 are turned on. The current flow direction is as follows: Figure 7As indicated by the arrows, current flows through the back-to-back MOS switch 23-2, the second connection point B, switch 24-2 in the cell commutation switch group 24, switch 22-1 in the excitation switch group 22, point E, point F, switch 22-4 in the excitation switch group 22, switch 24-3 in the cell commutation switch group 24, the first connection point A, and the back-to-back MOS switch 23-3. This achieves the discharge of the first even-numbered cell 112. In the initial stage of discharge, the current flowing through the coil of the primary side 301 of the voltage conversion module 30 gradually increases.

[0108] When the current in the discharge excitation branch remains stable and the rate of change of the current decreases to the rate of change threshold, the switch 22-4 of the excitation switch group 22 is turned off. The current direction will flow along the loop from point E, point F, switch 22-3, and switch 22-1, and then back to point E (e.g., ...). Figure 8 As shown in the diagram, the current gradually decreases. With this configuration, the excitation switch group 22 and the primary side 301 of the voltage conversion module 30 cooperate to form an excitation branch, and energy transfer is achieved through discharge, which can improve energy utilization and reduce energy waste.

[0109] Figure 9 As shown Figure 3 The circuit diagram shown is a partial circuit diagram of the discharge and charging of the odd-numbered cells 111 on the low-voltage side of the battery equalization system 1. Figure 9 The diagram shows the charging process of even-numbered cells 112. Figure 9 The illustrated embodiments and Figure 6 Similar to the illustrated embodiment, the charging process of even-numbered cells 112 is similar to that of odd-numbered cells 111, and the discharge current flow direction of even-numbered cells 112 is basically the same as that of odd-numbered cells 111. The main difference is that the second selection branch 242 of the cell commutation switch group 24 is turned on, that is, the switching transistors 24-2 and 24-3 of the cell commutation switch group 24 are turned on. The current flow direction is as follows: Figure 9 As indicated by the arrows, the current flows through the back-to-back MOS switch 23-3, the first connection point A, the switch 24-3 in the cell commutation switch group 24, the switch 22-4 in the excitation switch group 22, points F and E, the switch 22-1 in the excitation switch group 22, the switch 24-2 in the cell commutation switch group 24, the second connection point B, and the back-to-back MOS switch 23-2. This achieves the charging of the first even-numbered cell 112. The direction of the charging current for this even-numbered cell 112 is opposite to the direction of the discharging current. With this configuration, the excitation switch group 22 and the primary side 301 of the voltage conversion module 30 cooperate to form an excitation branch, achieving energy transfer through charging, which can improve energy utilization and reduce energy waste.

[0110] Figure 10 As shown Figure 3The circuit diagram shown is a partial circuit diagram of the discharge of odd-numbered cells 111 on the high-voltage side of the battery balancing system 1. Figure 10 The diagram shows the discharge process of odd-numbered cells 111 on the high-voltage side. Figure 10 The illustrated embodiments and Figure 4 The embodiments shown are similar, and the direction of current flow is as follows: Figure 10 As indicated by the arrows, the current flows through the back-to-back MOS switch 23-1, the first connection point A, the switch 24-1 in the cell commutation switch group 24, point G, point H, the drive switch group 22, the switch 24-4 in the cell commutation switch group 24, the second connection point B, and the back-to-back MOS switch 23-2. See the description above for details; further elaboration will not be repeated here.

[0111] Figure 11 As shown Figure 3 The circuit diagram shown illustrates the discharge of odd-numbered cells 111 on the high-voltage side of the battery balancing system 1. Figure 11 The diagram shows the discharge process of odd-numbered cells 111 on the high-voltage side. Figure 11 The illustrated embodiments and Figure 7 The embodiments shown are similar, and the direction of current flow is as follows: Figure 11 As indicated by the arrows, current flows through the back-to-back MOS switch 23-2, the second connection point B, switch 24-4 in the cell commutation switch group 24, the drive switch group 22, point H, point G, switch 24-1 in the cell commutation switch group 24, the first connection point A, and the back-to-back MOS switch 23-1. This achieves the charging of the first odd-numbered cell 111. See the description above for details; further elaboration is omitted here.

[0112] It should be noted that the discharge and charging processes of odd-numbered and even-numbered cells on the high-voltage side are similar to those on the low-voltage side, and the repeated parts will not be repeated. It should also be noted that when odd-numbered or even-numbered cells on the low-voltage side discharge, odd-numbered and even-numbered cells on the high-voltage side charge, thus achieving energy transfer. Similarly, when odd-numbered and even-numbered cells on the high-voltage side discharge, odd-numbered or even-numbered cells on the low-voltage side charge, thus achieving energy transfer. The cell data for charging and discharging is set accordingly, but the number of odd-numbered and even-numbered cells is not limited, nor is the quantity of odd-numbered and even-numbered cells limited.

[0113] Figure 12 As shown Figure 3 The circuit diagram of the voltage conversion module 30 of the battery equalization system 1. Figure 12 The coupling process of voltage conversion module 30 is shown. The primary side 301 and secondary side 302 of voltage conversion module 30 exchange magnetic field energy. According to the law of electromagnetic induction, the induced electromotive force is: Where L is the inductance coefficient and E is the induced electromotive force.

[0114] Based on the ideal transformer and characteristics of voltage conversion module 30: (1); (2); in, , The number of turns in the coil is indicated by a negative sign, which means the current flows in the opposite direction.

[0115] Assuming the right-side cell is discharging, when the excitation switch group 22 is controlled to open, i2 gradually increases, di2 / dt>0, and the induced electromotive force (EMF) is upward, with positive induced EMFs at points G and E. The current i1 flows from point F to point E. Meanwhile, i2, due to the gradually increasing voltage difference (cell voltage - induced EMF), gradually increases in the direction of current flowing from point G to point H. Figure 12 As shown. When the excitation switch group 22 is controlled to close, i2 decreases. Points F and H are the positive terminals of the induced electromotive force, which tend to drive i1 to flow in the opposite direction, causing i1 to gradually decrease. One switching cycle of the excitation switch group 22 ends.

[0116] exist Figure 12 In the illustrated embodiment, the excitation branch formed by the primary side 301 of the voltage conversion module 30 and the excitation switch group 22, and the excitation branch formed by the secondary side 302 of the voltage conversion module 30 and the excitation switch group 22, are functionally interchangeable. The specific selection is based on parameters such as the allowable withstand voltage, lifespan, and allowable current of the device. Furthermore, the number of turns of the coils of the primary side 301 and the secondary side 302 of the voltage conversion module 30 are determined according to the rated voltage of the 12V small battery cell and the rated voltage of the high-voltage storage battery cell, referring to formula (1). Therefore, during active balancing, the number of cells participating in balancing on both sides remains consistent. For example, balancing of 1 to 4 cells can be performed simultaneously. With this setting, active balancing can be achieved, the balancing current can be increased, and the balancing speed can be accelerated. In this embodiment, by utilizing the high power conversion capability of the DCDC converter and the absence of the heating effect of the balancing resistor in passive balancing, the balancing speed can be effectively improved.

[0117] Figure 13 As shown Figure 3 A circuit diagram of another embodiment of the battery equalization system 1 shown. Figure 13 The illustrated embodiments and Figure 3 The embodiments shown are similar, the main difference being that... Figure 13 In the illustrated embodiment, at least two battery modules 10 include two modules with the same rated voltage and located within the same high-voltage battery. Since the voltage conversion module 30 isolates two sets of cells, it divides the same high-voltage battery into different modules, or two sets of cells within a string, such as... Figure 13 The multi-module scheme shown has the same working principle and can operate between the upper and lower half of the battery cell string. Energy is transferred between different modules within the same high-voltage battery, achieving efficient energy utilization and avoiding energy waste.

[0118] Figure 14 The diagram shown is a flowchart of one embodiment of the battery balancing control method of this application. Figure 14 As shown, the battery balancing control method is applied as described above. Figures 1 to 13 The battery balancing system 1 shown in the embodiment. The battery balancing control method includes the following steps S1 to S4.

[0119] Step S1: Obtain the voltage of multiple cells 11 in at least two battery modules 10. The voltage of each cell in the low-voltage side battery module and the high-voltage side battery module can be monitored in real time by the battery management chip 105.

[0120] Step S2: Determine the voltage capacity to be balanced based on the difference between the voltage of each cell 11 and the average voltage. At the end of charging (cell voltage > 3.6V [TBD]) or when the vehicle is stationary, calculate the capacity to be balanced based on the difference between the voltage of each cell and the average cell voltage.

[0121] For example, since there is a mapping relationship between the voltage of a battery cell and the battery capacity, the average capacity required for a single battery cell is [SOCu - SOCuavg] * C_rate. Here, SOCu represents the cell capacity, SOCuavg represents the average cell capacity, and C_rate represents the cell's rated capacity. The rated capacity of the battery cell is calculated each time the above scenario conditions are met.

[0122] Step S3: Based on the required voltage capacity for balancing, select the cells 11 that need to be balanced, thus identifying at least one cell 11 from one battery module 10 as the requester and at least one cell 11 from another battery module 10 as the receiver. Based on the voltage capacity, determine whether a specific cell needs to be discharged or charged, and determine the specific number of cells participating in the balancing process.

[0123] Step S4: Perform voltage equalization based on the voltage of the battery cells 11 of the determined requester and receiver. Once the requester and receiver are determined, the voltage capacity and quantity of the battery cells that need to be discharged and charged are also determined.

[0124] The battery balancing control method of this application embodiment is applied as described above. Figures 1 to 13 The battery balancing system 1 shown in the embodiment realizes energy transfer, reduces energy waste, improves energy utilization, increases balancing current, and speeds up balancing.

[0125] In some embodiments, step S3, selecting the cells 11 that need to be balanced according to the required voltage capacity, to determine at least one cell 11 of one battery module 10 as the requester and at least one cell 11 of another battery module 10 as the receiver, includes: Based on the difference between the voltage of each cell 11 and the average voltage, cells 11 with the highest voltage and cells 11 with the lowest voltage are selected. Based on the difference between the highest voltage and the average voltage, and the difference between the voltage of at least two adjacent cells 11 and the average voltage, the cell 11 with the highest voltage is determined to be a single high-capacity cell. Based on the difference between the lowest voltage and the average voltage, and the difference between the voltage of at least two adjacent cells 11 and the average voltage, the cell 11 with the lowest voltage is determined to be a single low-capacity cell. One of these single high-capacity cells and single low-capacity cells is designated as the requester, and the other as the receiver.

[0126] Figure 15 As shown Figure 14 A schematic diagram of a single high-capacity cell identified in the battery balancing control method shown. Figure 15 In the illustrated embodiment, Umax-Uavg > 250mV and Unbr-Uavg <= 0 mV. Here, Umax represents the maximum voltage, Uavg represents the average voltage, and Unbr represents the two cells adjacent to the cell with the maximum voltage. A single high-capacity cell thus defined is... Figure 15 The battery cell shown is number 3.

[0127] Figure 16 As shown Figure 14 A schematic diagram of a single low-capacity cell identified in the battery balancing control method shown. Figure 16 In the illustrated embodiment, Umin-Uavg < -250mV and Unbr-Uavg >= 0 mV. Here, Umin represents the minimum voltage, Uavg represents the average voltage, and Unbr represents the two cells adjacent to the cell with the maximum voltage. A single low-capacity cell is thus defined as... Figure 15 The battery cell shown is number 2.

[0128] With this setup, the individual high-capacity voltage and individual low-capacity voltage are determined by the voltage of cell 11 and the average voltage, thereby identifying the requester and receiver. This allows for precise location of the cell 11 that needs to participate in the balancing process, resulting in high balancing accuracy and good balancing effect.

[0129] In some embodiments, step S3, selecting the cells 11 that need to be balanced according to the required voltage capacity, to determine at least one cell 11 of one battery module 10 as the requester and at least one cell 11 of another battery module 10 as the receiver, includes: Based on the difference between the voltage of each cell 11 and the average voltage, cells 11 with the highest voltage and cells 11 with the lowest voltage are selected. Based on the difference between the highest voltage and the average voltage, and including the cell 11 with the highest voltage and the difference between the voltage and the average voltage of at least three consecutive cells 11, the at least three consecutive cells 11 are determined to be multiple high-capacity cells. Based on the difference between the lowest voltage and the average voltage, and including the cell 11 with the lowest voltage and the difference between the voltage and the average voltage of at least three consecutive cells 11, the at least three consecutive cells 11 are determined to be multiple low-capacity cells. Multiple high-capacity cells and multiple low-capacity cells are determined, one of which is the requester and the other is the receiver.

[0130] Figure 17 As shown Figure 14 A schematic diagram of multiple high-capacity cells identified in the battery balancing control method shown. Figure 17 In the illustrated embodiment, Umax-Uavg > 200mV, and the U-Uavg of three consecutive cells including Umax > 10mV. Here, Umax represents the maximum voltage, Uavg represents the average voltage, and Unbr represents the voltage of the three consecutive cells including Umax. The plurality of high-capacity cells thus determined are... Figure 17 Cells 2, 3, and 4 are shown.

[0131] Figure 18 As shown Figure 14 A schematic diagram of multiple low-capacity cells identified in the battery balancing control method shown. Figure 18 In the illustrated embodiment, Umin-Uavg < -200mV, and the U-Uavg of three consecutive cells containing Umin < 10mV. Here, Umin represents the minimum voltage, Uavg represents the average voltage, and Unbr represents the voltage of three consecutive cells containing Umin. The plurality of low-capacity cells thus defined are... Figure 18 Cells 2, 3, and 4 are shown.

[0132] When any condition of the requester is met, the corresponding cell is selected at the receiver. A high capacity cell for the requester means it needs to be discharged, requiring a low-capacity cell to be found at the receiver. Furthermore, the number of cells on the requester and receiver must be equal. When the sender's cell finds a cell on the receiver, voltage equalization begins. This setup determines multiple high-capacity and multiple low-capacity voltages by analyzing the voltage and average voltage of cell 11, thereby identifying the requester and receiver. This allows for precise location of the cell 11 required for equalization and enables equalization of multiple cells 11, resulting in high equalization efficiency.

[0133] It should be noted that the requesting party's battery cells can be either high-capacity or low-capacity cells. In other words, the requesting party can request both discharging and charging. Correspondingly, the receiving party can receive both discharging and charging. Similarly, both the requesting and receiving parties can have an odd or even number of battery cells. The number of cells can be one or more, but the amount charged and discharged must be equal to maintain energy transfer balance. For specific charging and discharging processes, please refer to the above text. Figures 1 to 13 The battery balancing system 1 shown in the embodiment will not be described in detail here.

[0134] In some embodiments, step S4, performing voltage equalization based on the voltages of the determined requester and receiver's cells 11, includes: When the voltage of one of the at least one battery cell 11 as the requester and the at least one battery cell 11 as the receiver is higher than the average voltage, it is determined that the at least one battery cell 11 is discharging; when the voltage of the other battery cell 11 is lower than the average voltage, it is determined that the at least one battery cell 11 is charging.

[0135] In some embodiments, when the voltage of the requesting cell is higher than the average voltage, the cell discharges; when the voltage of the receiving cell is lower than the average voltage, the cell charges. In other embodiments, when the voltage of the requesting cell is lower than the average voltage, the cell charges; when the voltage of the receiving cell is higher than the average voltage, the cell discharges. The requesting and receiving cells 11 can select charging and discharging according to the actual voltage to achieve energy transfer, thereby achieving efficient energy utilization, avoiding energy waste, increasing the balancing current, and accelerating the balancing speed.

[0136] In some embodiments, the battery equalization control method further includes: In non-charging scenarios, voltage balancing begins when the voltage difference between the maximum voltage of one cell 11 in one battery module 10 and the minimum voltage of one cell 11 in another battery module 10 is greater than a first voltage threshold.

[0137] In some embodiments, the first voltage threshold can be 300 mV. In non-charging scenarios, voltage equalization begins when Umax - Umin > 300 mV. Here, Umax represents the maximum voltage, and Umin represents the minimum voltage.

[0138] In a charging scenario, voltage equalization begins when the voltage difference between the maximum voltage of one cell 11 in one battery module 10 and the minimum voltage of one cell 11 in another battery module 10 is greater than a second voltage threshold. The first voltage threshold is greater than the second voltage threshold.

[0139] In some embodiments, the second voltage threshold can be 260 mV. In charging scenarios, this occurs when Umax - Umin > 260 mV. The aim is to encourage active balancing during charging, utilizing the charging station's power to maintain battery balance.

[0140] With this setup, voltage balancing can be performed in both charging and non-charging scenarios, and the power from the charging pile can keep the battery module 10 balanced. This allows for simultaneous charging and balancing, keeping the cell capacity consistent, increasing the amount of power per charge, and thus extending the driving range of the battery module 10.

[0141] In some embodiments, the battery balancing control method further includes: stopping voltage balancing when it is determined that the voltage capacity to be balanced for the requesting cell 11 is 0, or the voltage of the receiving cell 11 reaches the average voltage. This configuration stops balancing when it is not needed, thus achieving on-demand balancing, reducing energy loss, and improving overall system efficiency.

[0142] In some embodiments, the number of battery cells 11 in the requesting party is the same as the number of battery cells 11 in the receiving party. Maintaining the same number of battery cells 11 in both parties ensures balanced energy transfer and stable, reliable operation.

[0143] In the above embodiment, when the balancing condition is met, the main control module of the battery management chip 105 first controls the cell selection switch group 23 in the front-end analog chip 104 to select cells. If the starting cell is an even number, the commutation switch group is controlled to commutate. Subsequently, the excitation switch group switches periodically under the control of the pulse signal wave of the switch control module of the battery management chip 105. The balancing current magnitude is controlled by the duty cycle and frequency of the pulse signal wave. When the exit balancing condition is met, balancing stops. All relevant switch groups are in the off position.

[0144] Figure 19 The diagram shown is a structural block diagram of one embodiment of the battery balancing control device 3 of this application. Figure 19As shown, the battery balancing control device includes one or more processors 31 for implementing, as Figure 14 The battery balancing control method shown in the embodiment. The computer storage medium 32 of this application embodiment stores a program that, when executed by a processor, implements the method described above. Figure 14 The battery balancing control method shown in the embodiment. The computer-readable storage medium 32 may store a program that can be called by the processor 31, and may include a non-volatile storage medium. In some embodiments, the processor 31 may include memory 33 and an interface 34. In some embodiments, the processor 31 may also include other hardware depending on the actual application. This application also provides a vehicle, including the above-described... Figure 7 The battery balancing control device shown in the embodiment.

[0145] This application may take the form of a computer program product implemented on one or more computer-readable storage media 32 (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. The computer-readable storage media 32 includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented using any method or technology. The information may be computer-readable instructions, data structures, program modules, or other data.

[0146] Examples of computer-readable storage media 32 include, but are not limited to: phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transfer medium that can be used to store information that can be accessed by a computing device.

[0147] It should be understood that this application is not limited to the content already described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery balancing system, characterized in that, include: At least two battery modules, each of which includes multiple battery cells; A switch matrix is ​​electrically connected to each of the battery modules; and, A voltage conversion module is electrically connected to the switch matrix and shared by the at least two battery modules; the switch matrix is ​​selectively controlled so that at least one cell of one of the at least two battery modules and at least one cell of the other of the at least two battery modules are respectively connected to and have their energy transferred through the voltage conversion module, so as to balance the voltage between the at least two battery modules. The voltage conversion module includes a primary side and a secondary side; the switch matrix includes a cell switch group and an excitation switch group electrically connected to the cell switch group; the cell switch group is electrically connected to the plurality of cells of each battery module, and the excitation switch group is electrically connected to the primary side and the secondary side, and forms an excitation branch with the primary side and the secondary side; When one of the cells in one battery module is charging and the other is discharging, the excitation branch located on the same side as the discharging cell is the discharge excitation branch; the cell switch group and the excitation switch group are selectively controlled so that the discharging cell is connected to the voltage conversion module; When the current magnitude of the discharge excitation branch remains stable and the rate of change of the current decreases to the rate of change threshold, the cell switch group and the excitation switch group are selectively controlled to disconnect the discharged cell from the voltage conversion module, and the excitation switch group and the voltage conversion module form a freewheeling circuit; The main control module is configured to: acquire the voltages of multiple cells from at least two battery modules; determine the voltage capacity to be balanced based on the difference between the voltage of each cell and the average voltage; select the cells to be balanced based on the voltage capacity to be balanced, thereby determining at least one cell from one of the battery modules as a requester and at least one cell from the other battery module as a receiver; and perform voltage balancing based on the voltages of the determined cells from the requester and receiver. In a non-charging scenario, voltage equalization begins when the voltage difference between the maximum voltage of one cell in one battery module and the minimum voltage of one cell in another battery module is greater than a first voltage threshold. In a charging scenario, voltage equalization begins when the voltage difference between the maximum voltage of one cell in one battery module and the minimum voltage of one cell in another battery module is greater than a second voltage threshold. Wherein, the first voltage threshold is greater than the second voltage threshold.

2. The battery balancing system according to claim 1, characterized in that, The plurality of battery cells includes a plurality of odd-numbered battery cells and a plurality of even-numbered battery cells; The cell switch group includes multiple cell selection switch groups and cell reversing switch groups. The multiple cell selection switch groups are electrically connected to the multiple cells of each battery module, and the cell reversing switch groups are electrically connected to the multiple cell selection switch groups and the excitation switch group. The cell selection switch group is used to select at least one odd-numbered cell or at least one even-numbered cell in each battery module that needs to participate in voltage equalization; the cell reversing switch group is used to switch the positive and negative terminals of the odd-numbered cells and the even-numbered cells.

3. The battery balancing system according to claim 1, characterized in that, The switch matrix includes a cell switch group and an excitation switch group electrically connected to the cell switch group, and the excitation switch group is electrically connected to the voltage conversion module. The plurality of battery cells includes a plurality of odd-numbered battery cells and a plurality of even-numbered battery cells; The cell switch group includes multiple cell selection switch groups and cell reversing switch groups. The multiple cell selection switch groups are electrically connected to the multiple cells of each battery module, and the cell reversing switch groups are electrically connected to the multiple cell selection switch groups and the excitation switch group. The cell selection switch group is used to select at least one odd-numbered cell or at least one even-numbered cell in each battery module that needs to participate in voltage equalization; the cell reversing switch group is used to switch the positive and negative terminals of the odd-numbered cells and the even-numbered cells, so that the discharging cells and the charging cells can be voltage equalized through the excitation switch group and the voltage conversion module.

4. The battery balancing system according to claim 2 or 3, characterized in that, The cell reversing switch group includes a first selection branch and a second selection branch; When at least one of the odd-numbered cells in one of the battery modules is charging or discharging, the cell selection switch group connected to the positive and negative terminals of the at least one odd-numbered cell is controlled to be turned on, and the first selection branch of the cell reversing switch group is controlled to be turned on, so that the at least one odd-numbered cell is connected to the voltage conversion module through the excitation switch group and performs voltage conversion through the voltage conversion module; When at least one of the even-numbered cells in one of the battery modules is charging or discharging, the cell selection switch group connected to the positive and negative terminals of the at least one even-numbered cell is controlled to be turned on, and the second selection branch of the cell reversing switch group is controlled to be turned on, so that the at least one even-numbered cell is connected to the voltage conversion module through the excitation switch group, and voltage conversion is performed through the voltage conversion module.

5. The battery balancing system according to claim 4, characterized in that, The positive terminals of the odd-numbered cells converge at a first connection point through the corresponding cell selection switch group, and the negative terminals of the odd-numbered cells converge at a second connection point through the corresponding cell selection switch group; when at least one of the odd-numbered cells of one of the battery modules is charging or discharging, the first connection point is the positive terminal convergence point, and the second connection point is the negative terminal convergence point; The positive terminals of the even-numbered cells converge at the second connection point through the corresponding cell selection switch group, and the negative terminals of the even-numbered cells converge at the first connection point through the corresponding cell selection switch group; when at least one of the even-numbered cells of one of the battery modules is charging or discharging, the second connection point is the positive terminal convergence point, and the first connection point is the negative terminal convergence point; The cell reversing switch group is used to switch the positive terminal junction and the negative terminal junction of the odd-numbered cells and the even-numbered cells by switching the first selection branch and the second selection branch.

6. The battery balancing system according to claim 1, characterized in that, The excitation branch located on the same side as the charging cell is the charging excitation branch, and the discharging excitation branch transfers energy with the charging excitation branch; The discharge excitation branch has the opposite current direction to the charging excitation branch.

7. The battery balancing system according to claim 1, characterized in that, The switch matrix includes multiple cell selection switch groups and cell commutation switch groups; the battery balancing system also includes a front-end analog chip and a battery management chip. The multiple cell selection switch groups are integrated into the front-end analog chip, and the cell commutation switch groups, the excitation switch groups, and the voltage conversion module are all integrated into the battery management chip.

8. The battery balancing system according to claim 7, characterized in that, The battery balancing system further includes a switch control module, with both the main control module and the switch control module integrated within the battery management chip. The main control module is electrically connected to the switch control module and the front-end analog chip, and the switch control module is electrically connected to the cell commutation switch group and the excitation switch group. The main control module is used to control the on / off state of the cell commutation switch group and the excitation switch group by controlling the switch control module, and is also used to control the on / off state of the multiple cell switch groups by controlling the front-end analog chip; and / or, The battery balancing system also includes a data acquisition module, which is integrated into the front-end analog chip and electrically connected to the plurality of cells of each battery module; the data acquisition module is used to acquire data from each cell.

9. The battery balancing system according to claim 1, characterized in that, The at least two battery modules include two separately configured battery packs with different rated voltages, wherein the two battery packs include a low-voltage battery pack and a high-voltage battery pack; or, The at least two battery modules include two modules with the same rated voltage and located in the same high-voltage storage battery.

10. The battery balancing system according to claim 1, characterized in that, When one of the cells in one battery module is charging and the other is discharging, the number of cells discharging is the same as the number of cells charging; and / or, The switch matrix includes a cell commutation switch group and an excitation switch group; the battery balancing system further includes a current sensor, which is electrically connected between the cell commutation switch group and the excitation switch group; and / or The switch matrix includes multiple cell selection switch groups; each cell selection switch group includes a pair of back-to-back MOS switches; and / or, The switching matrix includes a cell commutation switch group, which includes a full-bridge switch group or MOSFET switches; and / or, The switch matrix includes an excitation switch group, which includes a full-bridge switch group or MOS switches.

11. A battery equalization control method, characterized in that, The battery balancing system is applied to any one of claims 1 to 10; the battery balancing control method includes: Obtain the voltage of multiple cells from at least two battery modules; The voltage capacity that needs to be balanced is determined based on the difference between the voltage of each cell and the average voltage. Based on the required voltage capacity balancing, select the cells that need balancing to determine at least one cell from one of the battery modules as the requester and at least one cell from the other battery module as the receiver; and, Voltage equalization is performed based on the voltage of the battery cell determined by the requester and the receiver; The battery equalization control method further includes: In a non-charging scenario, voltage equalization begins when the voltage difference between the maximum voltage of one cell in one battery module and the minimum voltage of one cell in another battery module is greater than a first voltage threshold. In a charging scenario, voltage equalization begins when the voltage difference between the maximum voltage of one cell in one battery module and the minimum voltage of one cell in another battery module is greater than a second voltage threshold. Wherein, the first voltage threshold is greater than the second voltage threshold.

12. The battery equalization control method according to claim 11, characterized in that, The step of selecting cells to be balanced based on the required voltage capacity, and determining at least one cell from one of the battery modules as the requester and at least one cell from another battery module as the receiver, includes: Based on the difference between the voltage of each cell and the average voltage, the cells with the maximum voltage and the cells with the minimum voltage are selected. Based on the difference between the maximum voltage and the average voltage, and the difference between the voltage of at least two cells adjacent to the cell having the maximum voltage and the average voltage, the cell having the maximum voltage is determined to be a single high-capacity cell. Based on the difference between the minimum voltage and the average voltage, and the difference between the voltage of at least two adjacent cells having the minimum voltage and the average voltage, the cell having the minimum voltage is determined to be a single low-capacity cell; and, The individual high-capacity battery cell and the individual low-capacity battery cell are identified, with one of them being the requester and the other being the receiver.

13. The battery equalization control method according to claim 11, characterized in that, The step of selecting cells to be balanced based on the required voltage capacity, and determining at least one cell from one of the battery modules as the requester and at least one cell from another battery module as the receiver, includes: Based on the difference between the voltage of each cell and the average voltage, the cells with the maximum voltage and the cells with the minimum voltage are selected. Based on the difference between the maximum voltage and the average voltage, and the difference between the voltage of the cell having the maximum voltage and the voltage of at least three consecutive cells and the average voltage, the at least three consecutive cells are determined to be a plurality of high-capacity cells. Based on the difference between the minimum voltage and the average voltage, and the difference between the voltage of the cell having the minimum voltage and the average voltage of at least three consecutive cells, the at least three consecutive cells are determined to be a plurality of low-capacity cells; and, The plurality of high-capacity battery cells and the plurality of low-capacity battery cells are identified, with one of them being the requester and the other being the receiver.

14. The battery equalization control method according to claim 11, characterized in that, The step of voltage equalization based on the determined voltages of the battery cells of the requester and the receiver includes: When the voltage of one of the at least one battery cell that is the requesting party and the at least one battery cell that is the receiving party is higher than the average voltage, it is determined that the at least one battery cell is discharging; when the voltage of the other battery cell is lower than the average voltage, it is determined that the at least one battery cell is charging.

15. The battery equalization control method according to claim 11, characterized in that, The battery balancing control method further includes: stopping voltage balancing when the voltage capacity that the requesting party's battery cell needs to be balanced is 0, or when the voltage of the receiving party's battery cell reaches the average voltage; and / or, The number of battery cells in the requesting party is the same as the number of battery cells in the receiving party.

16. A computer storage medium, characterized in that, It stores a program that, when executed by a processor, implements the battery equalization control method as described in any one of claims 11 to 15.

17. A battery balancing control device, characterized in that, include: One or more processors are used to implement the battery equalization control method as described in any one of claims 11 to 15.

18. A vehicle, characterized in that, Includes the battery equalization control device as described in claim 17.

Images