Full-path large-current equalization topology, method and system based on bidirectional flyback conversion

Abstract

The invention belongs to the technical field of large-current equalization topology structures, and provides a full-path large-current equalization topology, method and system based on bidirectional flyback conversion, and the method comprises the steps: carrying out the initialization, continuously collecting the voltage of a battery, and calculating the voltage difference of a battery pack; judging whether the topology is in a standing state or not, if so, judging whether standing within a set time period is completed or not, if not, returning to collect the voltage again, if so, judging whether the voltage difference is smaller than a target value or not, and if so, ending equalization; otherwise, setting different PWM duty ratios of the corresponding switch groups according to the voltage difference, and switching to an equilibrium state; if the topology is not in the standing state, considering that the topology is in an equilibrium state, and judging whether continuous equilibrium reaches preset time or not; if not, keeping balance; if yes, balancing is paused, and a standing state is switched; and closed-loop battery equalization control is realized through alternate judgment and automatic switching of the two states.

Description

A topology, method, and system for end-path high-current equalization based on bidirectional flyback converter. Technical Field

[0001] This invention belongs to the field of high-current balancing topology technology, specifically relating to a full-path high-current balancing topology, method, and system based on bidirectional flyback converter. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In an environment where energy issues are becoming increasingly prominent, lithium-ion batteries, due to their small size and high energy density, are widely used in the field of new energy vehicles. However, in actual series applications of battery packs, problems such as reduced battery life, low energy utilization, and even thermal runaway safety hazards often occur. The root cause lies in the subtle differences between each individual battery cell. To address the inconsistency within the battery pack, battery equalization is an important method that can effectively reduce the differences between individual battery cells, thereby improving the overall performance of the battery pack.

[0004] Currently, passive equalization, which dissipates energy through resistor heating, is the most common application in BMS (Battery Management System). While passive equalization circuits are simple to design and inexpensive to manufacture, they suffer from significant energy waste and low equalization efficiency. Chinese patent CN202111191596.4 describes an equalization circuit based on a switching inductor, but this equalizer only achieves equalization between individual cells, limiting the selection of equalization paths. Chinese patent CN202211258897.9 presents an equalizer design based on an active half-bridge, requiring an inductor module for every two battery cells. This poses a significant challenge to the size and cost of the equalizer design when the number of battery cells is large. Furthermore, each pair of battery cells requires a transformer winding, increasing the design complexity and manufacturing cost of the transformer as the number of batteries increases. Many challenges remain in the design of high-current, full-path equalizers. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a full-path high-current equalization topology, method, and system based on bidirectional flyback converter. This invention achieves full-path high-current equalization by introducing an H-bridge switch array on the primary side, coupled with bidirectional excitation of a single transformer. Energy is entirely transferred via electromagnetic induction of the windings, eliminating the need for additional energy storage components and reducing the design cost and size of the equalizer. Furthermore, a hierarchical equalization strategy is established in terms of control, effectively reducing voltage fluctuations during the equalization process by dynamically adjusting the PWM wave duty cycle, thus mitigating the difficulty or non-convergence of equalization voltage convergence.

[0006] According to some embodiments, the present invention adopts the following technical solution: a full-path high-current balancing topology based on bidirectional flyback converter, comprising multiple battery cells connected in series, each battery cell being numbered sequentially, the positive terminals of battery cells with odd numbers being connected in series to two switch groups and then connected in series through a first branch, the positive terminals of battery cells with even numbers being connected in series to two switch groups and then connected in series through a second branch; between adjacent battery cells, the negative terminal of the preceding battery cell and the positive terminal of the following battery cell share the same switch group; an H-bridge switch array is provided between the first branch and the second branch, the middle end of the H-bridge switch array is connected to the primary side of the transformer, the two ends of the secondary side of the transformer are connected in series to the first branch, and the first branch is provided with switch groups between the connection points of the secondary side of the transformer to prevent short circuits on the secondary side of the transformer.

[0007] As an alternative implementation, the switch group for preventing short circuits on the secondary side of the transformer includes two switch groups connected in series.

[0008] As an alternative implementation, each end of the secondary side of the transformer is connected to the first branch via two series-connected switch groups.

[0009] As an alternative implementation, the switch groups are all MOSFETs, and the two switch groups connected in series are reversed.

[0010] The equalization control method based on the above topology includes the following steps: initialization, continuous acquisition of battery voltage and calculation of the voltage difference of the battery pack; determining whether the topology is in a static state, if so, determining whether the static period of the set time has been completed, if not, returning to re-acquiring voltage, if completed, proceeding to the next step; determining whether the voltage difference is less than the target value, if less than the target value, ending the equalization; otherwise, setting different PWM duty cycles of the corresponding switch groups according to the voltage difference and switching to the equalization state; if the topology is not in a static state, it is considered to be in an equalization state, determining whether the equalization has been continuously balanced for a predetermined time; if not, maintaining the equalization; if the equalization has been reached, pausing the equalization and switching to the static state; through the alternating judgment and automatic switching of the two states, closed-loop battery equalization control is achieved.

[0011] As an alternative implementation, the equalization control method is applied to the control process of any of the following: battery pack discharging to individual cells, individual cells discharging to battery pack, equalization between any individual cells, sub-cells discharging to the total battery pack, and the total battery pack discharging to sub-cells.

[0012] As a further defined implementation, during the control process of any item, the switch control state is maintained so that the transformer energy is completely depleted and enters a static state, so as to ensure that the balanced topology is always in the DCM intermittent working mode.

[0013] As an alternative implementation, the set time is shorter than the predetermined time.

[0014] A battery balancing control system includes: a voltage difference calculation module for continuously acquiring battery voltage and calculating the voltage difference of the battery pack; a first judgment module for determining whether the topology is in a static state; if so, determining whether a set time period of static adjustment has been completed; if not, calling the voltage difference calculation module; if completed, calling the second judgment module; the second judgment module for determining whether the voltage difference is less than a target value; if less than the target value, ending the balancing process; otherwise, setting different PWM duty cycles for corresponding switch groups based on the voltage difference and switching to the balancing state; and an iterative balancing control module for determining whether the topology is in a balancing state if it is not in a static state, and determining whether the balancing process has been continuously balanced for a predetermined time; if not, maintaining the balancing process; if the balancing process has been reached, pausing the balancing process and switching to the static state; achieving closed-loop battery balancing control through alternating judgments and automatic switching between the two states.

[0015] An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the steps in the method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention uses a single linear transformer and H-bridge switch array to complete all energy transfer. Through the multi-mode switching mechanism of bidirectional flyback topology, it breaks through the hardware limitations of traditional multi-winding or multi-transformer schemes, effectively reducing the number of devices and the size of the equalizer.

[0017] This invention achieves true full-path coverage, supporting three typical scenarios: bidirectional balancing between any individual cells, global balancing from individual cells to the battery pack, and directional balancing from the battery pack to individual cells. It can also achieve hierarchical balancing by dividing the battery pack into sub-cells, significantly improving the flexibility of complex battery pack management.

[0018] This invention utilizes a hierarchical equalization strategy to effectively reduce battery voltage fluctuations by dynamically adjusting the PWM duty cycle, thereby achieving rapid convergence of the battery pack voltage and improving equalization efficiency.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 is a schematic diagram of the equalization topology of one embodiment; Figure 2 is a schematic diagram of the hierarchical equalization strategy of one embodiment; Figure 3 is a schematic diagram of the P2C voltage waveform of one embodiment; Figure 4 is a schematic diagram of the C2P voltage waveform of one embodiment; Figure 5 is a schematic diagram of the ACAC voltage waveform of one embodiment; Figure 6 is a schematic diagram of the SubPack2Pack voltage waveform of one embodiment; Figure 7 is a schematic diagram of the Pack2SubPack voltage waveform of one embodiment; Figure 8 is a schematic diagram of the battery pack discharging to a single cell of one embodiment; Figure 9 is a schematic diagram of the battery cell discharging to the battery pack of one embodiment; Figure 10 is a schematic diagram of any single cell discharging to any single cell of one embodiment; Figure 11 is a schematic diagram of the sub-battery pack discharging to the total battery pack of one embodiment; Figure 12 is a schematic diagram of the total battery pack discharging to the sub-battery pack of one embodiment. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] Where there is no conflict, the embodiments and features described in this application may be combined with each other.

[0026] A full-path high-current equalization topology based on bidirectional flyback transform is shown in Figure 1. Wherein, B1, B2, ..., B... 2n For each individual battery cell in the battery pack, n is the cell number. 11 Q 12 ...Q 2n1 Q 2n2 Q represents the switch group connecting individual battery cells. h11 Q h12 ...Q h41 Q h42 Indicates an H-bridge switch array, Q f11 Q f12 Q f21 Q f22 Indicates the secondary-side switch group, Q s1With Q s2 Used to prevent short circuits on the secondary side of the transformer. Typically, an AFE (Analog Front-End) chip is selected to acquire the battery voltage, and an MCU (Microcontroller Unit) is used to generate a PWM waveform to control the switching of the MOSFET.

[0027] Specifically, the topology includes multiple battery cells connected in series. Each battery cell is numbered sequentially. The positive terminals of battery cells with odd-numbered numbers are connected in series to two switch groups and then connected through the first branch. The positive terminals of battery cells with even-numbered numbers are connected in series to two switch groups and then connected through the second branch. Between adjacent battery cells, the negative terminal of the preceding battery cell and the positive terminal of the following battery cell share the same switch group. An H-bridge switch array is set between the first and second branches. The middle end of the H-bridge switch array is connected to the primary side of the transformer. The two ends of the secondary side of the transformer are connected in series to the first branch, and the first branch has switch groups between the connection points on the secondary side of the transformer to prevent short circuits on the secondary side of the transformer.

[0028] The switch group used to prevent short circuits on the secondary side of the transformer consists of two switch groups connected in series.

[0029] Each end of the secondary side of the transformer is connected to the first branch via two series-connected switch groups.

[0030] The switch groups are all MOSFETs, and the two switch groups connected in series are reversed.

[0031] As can be seen from the topology diagram, when the number of batteries increases, no additional transformer windings or H-bridge switch arrays are required. For a battery pack consisting of 2n batteries, the topology only requires 2n+16 MOSFETs and one transformer, without the need for additional resistors and capacitors. This significantly reduces the number of components and the size of the equalizer, improving equalization efficiency while ensuring stable operation.

[0032] To better illustrate the working process, the following assumptions are made: 1) On the primary side, the direction of flow out of the individual battery cells is positive, and the direction of flow into the battery pack on the secondary side is positive. The voltage on the primary side of the transformer is positive when it is positive at the top and negative at the bottom, and the voltage on the secondary side is positive when it is negative at the top and positive at the bottom.

[0033] 2) When the current flows from top to bottom on the primary side, the magnetic flux is positive; when the current flows from bottom to top on the secondary side, the magnetic flux is negative.

[0034] 3) PWM+ indicates positive PWM, which controls the MOSFET to turn on; PWM- indicates negative PWM, which controls the MOSFET to turn off.

[0035] 4) Batteries B1, B3, B5, ..., B （2n-1）Odd-numbered batteries; batteries B2, B4, B6, ..., B 2n It is an even number of batteries.

[0036] The equalization methods include: A. Battery pack to individual cell discharge (P2C) As shown in Figure 8, the process of battery pack to individual cell discharge is demonstrated using a four-cell equalization topology as an example. The red path represents the overall discharge path of the battery pack, and the blue path represents the charging path of the individual cells.

[0037] During the battery pack discharge process, the equations can be written according to Kirchhoff's laws: (1) This refers to the discharge current of the battery pack in the equalization path from the battery pack to the individual battery cells. The voltage of the battery pack. Indicates the equilibrium time.

[0038] (2) Where L s R is the inductance coefficient of the transformer secondary side. s Let be the equivalent resistance of all components in the secondary circuit. As can be seen from formulas (1) and (2), the current gradually increases and the discharge voltage gradually decreases during the discharge process of the battery pack.

[0039] During the charging process of a single battery cell, the equations can be written according to Kirchhoff's laws: (3) This indicates the voltage of a single battery cell. i represents the charging current of a single battery cell in the equalization path from the battery pack to the individual battery cell. p In the formula, i corresponds to the charging or discharging current of the battery pack. pp This refers to the initial current transmitted from the secondary side to the primary side during the balancing process.

[0040] (4) Where i pp R is the initial current transferred from the secondary side to the primary side of the transformer. p Let be the equivalent resistance on the primary side of the transformer. As can be seen from formulas (3) and (4), the charging current gradually decreases from its maximum value, while the charging voltage gradually decreases from its maximum value until the transformer is completely demagnetized.

[0041] (5) Δt represents the time required for the transformer to enter DCM mode. This represents the initial current transferred from the secondary side of the transformer to the primary side during the equalization process from the battery pack to the individual battery cells. f represents the switching operating frequency, and D represents the PWM duty cycle of the control switch.

[0042] At the last moment, maintain the same switching control state as the previous moment and wait for the transformer energy to be completely exhausted. At this time, the circuit enters a static state, ensuring that the equalizer is always in the DCM intermittent working mode.

[0043] B. Battery cell to battery pack discharge (C2P) is shown in Figure 9. Taking the balanced topology of four batteries as an example, the process of the battery pack discharging to the individual cells is demonstrated. The red path represents the discharge path of the individual cells, and the blue path represents the overall charging path of the battery pack.

[0044] When a single battery cell discharges, the equations can be written according to Kirchhoff's laws: (6) (7) Among them, This represents the discharge current of a single battery cell during the process of equalizing the battery cell into the battery pack. This represents the primary voltage of the transformer during the equalization process from individual battery cells to the battery pack. Where L... p R is the inductance coefficient of the primary side of the transformer. p Let be the equivalent resistance of all components in the primary circuit. From formulas (6) and (7), it can be seen that when a battery cell discharges to the primary side of the transformer, the discharge current gradually increases and the voltage gradually decreases.

[0045] During the battery pack charging process, the equations can be written according to Kirchhoff's laws: (8) (9) Among them, This represents the charging current of the battery pack during the process of equalizing individual battery cells into the battery pack. i represents the voltage on the secondary winding of the transformer during the balancing process from individual battery cells to the battery pack. ss This represents the initial current mapped from the primary side to the secondary side of the transformer. As can be seen from formulas (8) and (9), during the battery pack charging process, the charging current and charging voltage gradually decrease from their maximum values.

[0046] (10) At the last moment, maintain the same switching control state as the previous moment and wait for the transformer energy to be completely exhausted. At this time, the circuit enters a static state to ensure that the equalizer is always in the DCM intermittent working mode.

[0047] C. Arbitrary Cell Equalization (ACAC) As shown in Figure 10, the process of equalization between arbitrary cells is demonstrated using four batteries as an example. The red path represents the discharge path of cell B1, and the blue path represents the charging path of cell B3.

[0048] When B1 discharges to the primary side of the transformer, the equation can be written according to Kirchhoff's laws: (11) (12) As can be seen from formulas (11) and (12), the discharge current of a single battery cell gradually decreases from its maximum value, and the charging voltage gradually decreases.

[0049] The transformer charges B3 on its primary side. Using Kirchhoff's laws, the equations are as follows: (13) (14) Where i cc This is the instantaneous current when the primary current of the transformer switches. As can be seen from formulas (13) and (14), both the voltage and current gradually decrease during charging.

[0050] At the last moment, maintain the same switching control state as the previous moment and wait for the transformer energy to be completely exhausted. At this time, the circuit enters a static state, ensuring that the equalizer is always in the DCM intermittent working mode.

[0051] D. Sub-pack to main pack discharge (SubPack2Pack) As shown in Figure 11, the process of sub-pack to main pack discharge is demonstrated using four batteries as an example. The red path represents the discharge path of the sub-pack consisting of B1B2B3, and the blue path represents the charging path of the main pack.

[0052] When the sub-cell pack discharges, the equations can be written according to Kirchhoff's laws: (15) (16) As can be seen from formulas (15) and (16), when the sub-battery pack discharges to the primary side of the transformer, the discharge current gradually increases and the voltage gradually decreases.

[0053] During the overall battery pack charging process, the equations can be written according to Kirchhoff's laws: (17) This represents the charging current of the total battery pack during the process of equalizing the sub-battery packs to the total battery pack.

[0054] (18) Among them, i represents the voltage on the secondary winding of the transformer during the balancing process from the sub-cell packs to the main cell pack. ss This represents the initial current mapped from the primary side of the transformer to the secondary side. As can be seen from formulas (17) and (18), during the charging process of the entire battery pack, the charging current and voltage gradually decrease from their maximum values.

[0055] (19) At the last moment, maintain the same switching control state as the previous moment and wait for the transformer energy to be completely exhausted. At this time, the circuit enters a static state to ensure that the equalizer is always in the DCM intermittent working mode.

[0056] E. Discharging from the main battery pack to the sub-battery pack (Pack2SubPack) As shown in Figure 12, the process of discharging from the main battery pack to the sub-battery pack is demonstrated using four batteries as an example. The red path represents the discharge path of the main battery pack, and the blue path represents the charging path of the sub-battery pack composed of B1B2B3.

[0057] During the battery pack discharge process, the equations can be written according to Kirchhoff's laws: (20) (21) where L s R is the inductance coefficient of the transformer secondary side. s Let be the equivalent resistance of all components in the secondary circuit. As can be seen from formulas (20) and (21), the discharge current gradually increases and the discharge voltage gradually decreases during the discharge process of the battery pack.

[0058] During the charging process of a single battery cell, the equations can be written according to Kirchhoff's laws: (twenty two) This indicates the voltage of the sub-cell pack.

[0059] (23) Where i pp R is the initial current transferred from the secondary side to the primary side of the transformer. p Let be the equivalent resistance on the primary side of the transformer. As can be seen from formulas (22) and (23), the charging current gradually decreases from its maximum value, while the voltage gradually decreases from its maximum value until the transformer is completely demagnetized.

[0060] (24) At the last moment, maintain the same switching control state as the previous moment and wait for the transformer energy to be completely exhausted. At this time, the circuit enters a static state to ensure that the equalizer is always in the DCM intermittent working mode.

[0061] Layered Control Strategy: To ensure the efficient operation of the equalizer, a closed-loop equalization control strategy based on state switching is provided, as shown in Figure 2. All the above equalization methods can utilize this proposed closed-loop equalization control strategy. Upon startup, initialization is performed first, followed by the main loop, continuously acquiring battery voltage and calculating the battery pack voltage difference (Vdiff). The process then enters different states based on judgment conditions: If the system is in a static state, it checks whether a 1-second static period has been completed; if not, it returns to re-acquiring voltage; if completed, it further checks whether Vdiff is less than the target value—if less than the target value, equalization ends; otherwise, different PWM duty cycles are set according to Vdiff, and the system switches to the equalization state. If the system is in the equalization state, it checks whether equalization has been sustained for 5 seconds; if not, it maintains equalization; if it has been sustained, equalization is paused and the system switches to the static state. Through alternating judgments and automatic switching between these two states, closed-loop battery equalization control is achieved.

[0062] The specific values ​​mentioned above can be changed in other embodiments, such as changing the equalization duration judgment condition to 7 seconds.

[0063] To verify the effectiveness of the provided method, this embodiment constructed an equalization experimental platform consisting of eight lithium battery cells connected in series, and conducted equalization experiments for P2C, C2P, ACAC, SubPack2Pack, and Pack2SubPack, respectively. The experimental results are shown in Figure 3.

[0064] In the P2C experiment, as shown in Figure 3, the initial highest single-cell voltage was 3.2817V, the lowest single-cell voltage was 3.2724V, and the average voltage was 3.0758V. The voltage was eventually equalized to approximately 3V, with a voltage difference of 5mV between the highest and lowest single-cell voltages. The total equalization time was 24 minutes.

[0065] In the C2P experiment, as shown in Figure 4, the initial highest single-cell voltage was 3.2011V, the lowest single-cell voltage was 2.8577V, and the average voltage was 2.9719V. The voltage eventually equalized to approximately 2.9V, with a voltage difference of 5mV between the highest and lowest single-cell voltages. The total equalization time was 39 minutes.

[0066] In the ACAC experiment, as shown in Figure 5, the initial highest single-cell voltage was 3.1632V, the lowest single-cell voltage was 2.9645V, and the average voltage was 3.0758V. The voltage was eventually equalized to approximately 3V, with a voltage difference of 5mV between the highest and lowest single-cell voltages. The total equalization time was 22 minutes.

[0067] In the SubPack2Pack experiment, as shown in Figure 6, the initial highest single-cell voltage was 3.7550V, the lowest single-cell voltage was 3.5704V, and the average voltage was 3.5717V. The voltage was eventually equalized to approximately 3.5V, with a voltage difference of 10mV between the highest and lowest single-cell voltages. The total equalization time was 16 minutes.

[0068] In the Pack2SubPack experiment, as shown in Figure 7, the initial highest single-cell voltage was 3.2315V, the lowest single-cell voltage was 3.0567V, and the average voltage was 3.1319V. The voltage eventually equalized to approximately 3.1V, with a voltage difference of 5mV between the highest and lowest single-cell voltages. The total equalization time was 14 minutes.

[0069] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0070] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0071] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0072] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art without creative effort within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A full-path high-current equalization topology based on bidirectional flyback converter, characterized in that, It includes multiple battery cells connected in series. Each battery cell is numbered sequentially. The positive terminals of battery cells with odd-numbered numbers are connected in series to two switch groups and then connected in series through the first branch. The positive terminals of battery cells with even-numbered numbers are connected in series to two switch groups and then connected in series through the second branch. Between adjacent battery cells, the negative terminal of the preceding battery cell and the positive terminal of the following battery cell share the same switch group. An H-bridge switch array is set between the first branch and the second branch. The middle end of the H-bridge switch array is connected to the primary side of the transformer. The two ends of the secondary side of the transformer are connected in series with switch groups and then connected to the first branch. The first branch has switch groups between the connection points on the secondary side of the transformer to prevent short circuits on the secondary side of the transformer.

2. The full-path high-current equalization topology based on bidirectional flyback converter as described in claim 1, characterized in that, The switch group used to prevent short circuits on the secondary side of the transformer consists of two switch groups connected in series.

3. The full-path high-current equalization topology based on bidirectional flyback converter as described in claim 1, characterized in that, Each end of the secondary side of the transformer is connected to the first branch via two series-connected switch groups.

4. The full-path high-current equalization topology based on bidirectional flyback converter as described in claim 1, characterized in that, The switch groups are all MOSFETs, and the two switch groups connected in series are reversed.

5. The topology equalization control method based on any one of claims 1-4, characterized in that, Includes the following steps: Initialize the system, continuously collect battery voltage and calculate the voltage difference of the battery pack; determine if the topology is in a static state. If so, determine if the static state for the set time period has been completed. If not, return to collect voltage again. If completed, proceed to the next step; determine if the voltage difference is less than the target value. If less than the target value, end the equalization process. Otherwise, set different PWM duty cycles for the corresponding switch groups according to the voltage difference and switch to the balanced state; If the topology is not in a static state, it is considered to be in a balanced state, and it is determined whether the balance has been maintained for a predetermined time. If it has not been maintained, the balance is maintained. If it has been maintained, the balance is paused and switched to a static state. Through the alternation of the two states and automatic switching, closed-loop battery balancing control is achieved.

6. The equalization control method as described in claim 5, characterized in that, The equalization control method is applied to the control process of any of the following: battery pack discharging to individual cells, individual cells discharging to battery pack, equalization between any individual cells, sub-cells discharging to the total battery pack, and the total battery pack discharging to sub-cells.

7. The equalization control method as described in claim 6, characterized in that, in During the control process of any item, the switch control state is maintained so that the transformer energy is completely exhausted and enters a static state, so as to ensure that the balanced topology is always in the DCM intermittent working mode.

8. The equalization control method as described in claim 5, characterized in that, The set time is less than the predetermined time.

9. A balanced control system, characterized in that, include: The voltage difference calculation module is used to continuously collect battery voltage and calculate the voltage difference of the battery pack; The first judgment module is used to determine whether the topology is in a static state. If so, it determines whether the static state for the set time period has been completed. If not, it calls the voltage difference calculation module. If completed, it calls the second judgment module. The second judgment module is used to determine whether the voltage difference is less than the target value. If it is less than the target value, the equalization ends. Otherwise, set different PWM duty cycles for the corresponding switch groups according to the voltage difference and switch to the balanced state; The iterative equalization control module is used to determine whether the battery is in an equalized state if the topology is not in a static state, and whether it has been continuously equalized for a predetermined time. If it has not been equalized, it maintains the equalization; if it has been equalized, it pauses the equalization and switches to a static state. Through the alternating judgment and automatic switching between the two states, closed-loop battery equalization control is achieved.

10. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, perform the steps of the method according to any one of claims 5-8.

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