Path optimal active equalization method and system for adjacent battery coupling

Abstract

The invention provides a path optimal active equalization method and system for adjacent battery coupling. The method comprises the steps of collecting energy of each battery pack in a battery pack group, and obtaining unbalanced energy of each battery based on the energy of the battery packs; obtaining the minimum transmission energy of a transmission path between adjacent battery packs based on the unbalanced energy of the batteries; determining an energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path; according to the energy transmission direction of the transmission path, distributing a corresponding optimal working point for each transmission path; and based on the optimal working point, the energy transmission direction of each transmission path is converted into a control signal, and the optimal active equalization of the battery pack group is realized based on the control signal. According to the path optimization method for making the path decision by adopting the minimum transmission energy, the battery equalization without overlapping can be ensured, the path action frequency is minimum, and the path optimization of the equalization energy is realized.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a path-optimal active balancing method and system for adjacent battery coupling. Background Technology

[0002] In large-scale battery energy storage systems, the inconsistency between individual battery cells is a key factor affecting the overall system performance and lifespan. Active balancing technology, which achieves active energy transfer between batteries through external circuitry, is an effective means of solving this problem. Current mainstream balancing strategies, such as those using average value comparison or adjacent comparison methods to determine the activation path, have significant limitations. These strategies typically rely on local information for decision-making, resulting in a lack of a global perspective in balancing path selection. Specifically: 1) Overlapping path actions: Multiple transmission paths may charge and discharge the same battery pack simultaneously or alternately, causing energy to circulate repeatedly in a local area, forming "balance overlap" and reducing the overall balancing efficiency; 2) Frequent balancing actions: The control strategy only responds to the instantaneous imbalance state and fails to consider the cumulative effect of battery energy, resulting in frequent switching actions and increased system losses; 3) Long equalization time: Due to the non-optimal path selection, energy needs to go through multiple transfers before reaching the target battery, which prolongs the overall equalization cycle.

[0003] A literature search of existing technologies revealed Chinese patent CN120824891A, which proposes a battery balancing control method, system, and medium. This method dynamically adjusts the appropriate charging and discharging current for each battery in real time based on its current state, preventing rapid overcharging or over-discharging and achieving a dynamic balance in the charging and discharging speeds of each battery. This further ensures that all batteries can be fully charged or discharged simultaneously, improving the control accuracy and effectiveness of battery balancing and reducing safety risks. However, this battery balancing control method cannot fundamentally avoid problems such as overlapping path actions, numerous balancing actions, and long balancing times, which are not conducive to the rapid and efficient balancing of series-connected batteries. Especially... Figure 1 The adjacent cell to adjacent cell (AC2C) balancing topology shown in the diagram supports energy transfer between adjacent cells in hardware. Theoretically, it possesses the most flexible path selection capability; however, without intelligent path decision-making methods, this flexibility may actually increase control complexity and system uncertainty. Therefore, there is an urgent need to develop a balancing strategy that can avoid path overlap, minimize the number of actions, and make intelligent path decisions based on the system's accumulated energy state. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide a path-optimal active balancing method and system for adjacent battery coupling.

[0005] According to the first aspect of this application, a path-optimal active balancing method for adjacent battery coupling is provided, comprising: Collect the energy of each battery pack in the battery pack group, and obtain the unbalanced energy of each battery based on the energy of the battery pack; Based on the unbalanced energy of the battery, the minimum transmission energy of the transmission path between adjacent battery packs is obtained; Based on the minimum transmission energy of the transmission path, the energy transmission direction of each transmission path is determined; Based on the energy transmission direction of the transmission path, assign a corresponding optimal operating point to each transmission path; Based on the optimal operating point, the energy transmission direction of each transmission path is converted into a control signal, and the optimal active balancing of the battery pack group is achieved based on the control signal.

[0006] Optionally, the unbalanced energy of the battery pack is the energy of the battery pack minus the average energy of the battery pack group.

[0007] Optionally, for the transmission path path i(i+1) The expression for its minimum transmission energy is as follows: in, path i(i+1) Represents the i-th battery pack B i and the (i+1)th battery pack B i+1 The transmission path between them Indicates the transmission path path i(i+1) Minimum energy transmitted; E im，i For the i-th battery pack B i The imbalance of energy.

[0008] Optionally, determining the energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path includes: For a transmission path, if its minimum transmission energy is greater than zero, then the transmission path is a forward transmission path; if its minimum transmission energy is less than zero, then the transmission path is a reverse transmission path; if its minimum transmission energy is equal to zero, then the transmission path is an idle path. The energy transmission direction of the forward transmission path is along the series arrangement of the battery packs, starting from the previous battery pack B. i Pointing to the next battery pack B i+1The energy transmission direction of the reverse transmission path is along the series arrangement sequence of the battery packs, starting from the next battery pack B. i+1 Pointing to the previous battery pack B i There is no energy transfer between the two battery packs connected at both ends of the idle path.

[0009] Optionally, the step of assigning a corresponding optimal operating point to each transmission path based on the energy transmission direction of the transmission path includes: For the forward transmission path, the forward optimal operating point is used to achieve forward power transmission; for the reverse transmission path, the reverse optimal operating point is used to achieve reverse power transmission; for the idle path, the idle operating point is used.

[0010] Optionally, the positive optimal operating point is specifically: the point at which the shift ratio and frequency ratio of the transmission path achieve soft switching of energy transmission within the full load range, while minimizing the sum of return power and current stress during energy transmission, under the premise of satisfying the preset rated transmission power; at the positive optimal operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is φ. At the reverse optimal operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is -φ, and this phase difference φ is used as the optimal shift ratio D. At the idle operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is 0.

[0011] Optionally, the step of converting the energy transmission direction of each transmission path into a control signal based on the optimal operating point, and realizing the optimal active balancing of the battery pack group based on the control signal, includes: Determine the direction of each transmission path: For each transmission path, if it is a forward transmission path, then the direction O of the transmission path is 1; if it is a reverse transmission path, then the direction O of the transmission path is -1; if it is an idle path, then the direction O of the transmission path is 0. Based on the optimal phase shift ratio D corresponding to the positive optimal operating point, the absolute phase shift time of each half-bridge drive signal is obtained according to the following formula. T i : in, T i Represents the i-th battery pack B i The absolute phase shift time corresponding to the half-bridge drive signal; T s For switching cycles;T i(i+1) Indicates the transmission path path i(i+1) The relative phase shift time between the two half-bridge drive signals corresponding to the two connected battery packs; The absolute phase shift time is used as a control signal, and the absolute phase shift time of each half-bridge drive signal is set based on this control signal to achieve optimal active balancing of the battery pack group.

[0012] According to a second aspect of this application, a path-optimal active balancing system for adjacent battery coupling is provided, comprising: The data acquisition module is used to collect the energy of each battery pack in the battery pack group and obtain the unbalanced energy of each battery based on the energy of the battery pack. The energy extraction module is used to obtain the minimum energy of the transmission path between adjacent battery packs based on the unbalanced energy of the battery. A direction definition model is used to determine the energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path. The working point allocation module is used to allocate the corresponding optimal working point to each transmission path according to the energy transmission direction of the transmission path. The equalization module is used to convert the energy transmission direction of each transmission path into a control signal based on the optimal operating point, and to achieve optimal active equalization of the battery pack group based on the control signal.

[0013] According to a third aspect of this application, a non-transitory computer-readable storage medium is provided, on which a computer program is stored, characterized in that, when executed by a processor, the program implements the steps of the above-described path-optimal active balancing method for adjacent battery coupling.

[0014] According to a fourth aspect of this application, an electronic device is provided, characterized in that it comprises: At least one memory for storing program instructions; At least one processor is configured to invoke program instructions stored in the memory and execute the steps of the aforementioned path-optimal active balancing method for adjacent battery coupling according to the obtained program instructions.

[0015] This application provides a path-optimal active balancing method for adjacent battery coupling. Based on the unbalanced energy of each battery, it obtains the minimum transmission energy of the transmission path between two adjacent battery packs. Using this minimum transmission energy, it determines the energy transmission direction and optimal operating point of the transmission path, thereby achieving optimal active balancing of the battery pack group. This application employs a path optimization method that uses minimum transmission energy to make path decisions, ensuring no overlap in battery balancing and minimizing the number of path actions, thus achieving path optimization for balancing energy.

[0016] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0017] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the AC2C type equilibrium structure in the background technology; Figure 2 The background diagram shows the topology of a switch-multiplexed resonant switched capacitor. Figure 3 This is a schematic diagram of the path-optimal active balancing method in one embodiment of this application; Figure 4 This is a schematic diagram illustrating the implementation of a low-interaction-power active equalization strategy in one embodiment of this application; Figure 5 This is a schematic diagram of the mathematical model of the battery cluster in series and its active balancing system used in one embodiment of this application; Figure 6 This is a simulation graph of the entire energy balance process in one embodiment of this application; Figure 7 This is a schematic diagram of a path-optimal active balancing system in one embodiment of this application. Detailed Implementation

[0018] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0019] It should be noted that all information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with relevant regulations.

[0020] In large-scale battery energy storage systems, the inconsistency between individual battery cells is a key factor affecting the overall system performance and lifespan. Active balancing technology is an effective means to solve this problem. Currently, among mainstream balancing strategies, there is a lack of a control strategy that can guarantee the minimum total interaction energy and achieve fast and efficient balancing by utilizing an AC2C topology to address the energy imbalance problem among multiple battery packs in a series battery pack. This would overcome the shortcomings of existing balancing methods, such as large interaction energy loss and slow balancing speed. Based on the above problems, this application provides a path-optimal active balancing method for adjacent battery coupling to solve the aforementioned issues. The balancing method provided in this application is a battery pack balancing control strategy driven by accumulated imbalanced energy (AIE), applicable to AC2C structure balancing systems.

[0021] Reference Figure 3 As shown, this application provides a path-optimal active balancing method for adjacent battery coupling, including: S1. Collect the energy of each battery pack in the battery pack group, and obtain the unbalanced energy of each battery based on the energy of the battery pack; S2. Based on the unbalanced energy of the battery, obtain the minimum transmission energy of the transmission path between adjacent battery packs; S3. Determine the energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path; S4. Assign the corresponding optimal operating point to each transmission path according to the energy transmission direction of the transmission path; S5. Based on the optimal operating point, the energy transmission direction of each transmission path is converted into a control signal, and the optimal active balancing of the battery pack group is achieved based on the control signal.

[0022] The embodiments described above in this application obtain the minimum transmission energy of the transmission path between two adjacent battery packs based on the unbalanced energy of each battery. The minimum transmission energy is then used to determine the energy transmission direction and optimal operating point of the transmission path, thereby achieving optimal active balancing of the battery pack group. This application employs a path optimization method that uses minimum transmission energy to make path decisions, ensuring no overlap in battery balancing and minimizing the number of path actions, thus achieving path optimization for balanced energy.

[0023] In some specific embodiments of this application, the unbalanced energy of the battery pack is the energy of the battery pack minus the average energy of the battery pack group.

[0024] In the embodiments described above, the battery pack group is formed by connecting several battery packs in series, with each pair of adjacent battery packs forming a transmission path. The energy of the battery pack is the actual remaining energy of the battery pack. E packActual remaining energy E pack The product of the battery pack's real-time state of charge (SOC) and its rated energy is given. The average energy of the battery pack group is specifically the arithmetic mean of the actual remaining energy of the battery pack group. The expression for the unbalanced energy of the battery pack is as follows: Among them, E i For the i-th battery pack B i Energy; E pack,i For the i-th battery pack B i The actual remaining energy; E avg E represents the average energy of the battery pack group. im，i Let be the unbalanced energy of the i-th battery pack, where i is the ordinal number of the battery pack (i.e., the series sequence).

[0025] In some specific embodiments of this application, regarding the transmission path path i(i+1) The expression for its minimum transmission energy is as follows: in, path i(i+1) Represents the i-th battery pack B i and the (i+1)th battery pack B i+1 The transmission path between them Indicates the transmission path path i(i+1) Minimum energy transmitted; E im，i For the i-th battery pack B i The imbalance of energy.

[0026] The embodiments described above in this application propose the concept of accumulated unbalanced energy, for any transmission path. i(i+1) The accumulated unbalanced energy of the upstream battery pack is equal to the accumulated unbalanced energy of the downstream battery pack. This accumulated unbalanced energy must be transmitted through this transmission path, and the minimum energy that the transmission path needs to transmit (i.e., the minimum transmission energy) is the accumulated unbalanced energy value of that transmission path. Therefore, the energy transmission requirement of each transmission path can be determined by detecting the accumulated unbalanced energy of the upstream battery packs of each transmission path. Specifically, for the transmission path... Path i(i+1) Its two ends are respectively connected to the battery pack B i and battery pack B i+1 All upstream battery packs are the first battery pack. B 1 to battery pack B i All battery packs, and all downstream battery packs are battery packs.B i+1 To battery pack B n Let n be the total number of battery packs in the group. The expression for the minimum transmission energy of the transmission path is as follows: Among them, AIE i This represents the cumulative value of the unbalanced energy from the first battery pack to the ith battery pack.

[0027] In some specific embodiments of this application, determining the energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path includes: For a transmission path, if its minimum transmission energy is greater than zero, then the transmission path is a forward transmission path; if its minimum transmission energy is less than zero, then the transmission path is a reverse transmission path; if its minimum transmission energy is equal to zero, then the transmission path is an idle path. In the forward transmission path, the energy transmission direction is along the series arrangement of the battery packs, starting from the previous battery pack B. i Pointing to the next battery pack B i+1 The energy transfer direction of the reverse transmission path is along the series arrangement of the battery packs, starting from the next battery pack B. i+1 Pointing to the previous battery pack B i There is no energy transfer between the two battery packs connected at both ends of the idle path.

[0028] In the above embodiments of this application, the energy transmission direction of the transmission path is determined as follows: if the cumulative unbalanced energy value is positive, the energy transmission direction of the transmission path is marked as positive, and energy needs to be transmitted downstream; if the cumulative unbalanced energy value is negative, the energy transmission direction of the transmission path is marked as negative, and energy needs to be transmitted upstream; if the cumulative unbalanced energy value is zero, the energy transmission direction of the transmission path is marked as zero, and the transmission path is idle.

[0029] In some specific embodiments of this application, an optimal operating point is assigned to each transmission path according to the energy transmission direction of the transmission path, including: For the forward transmission path, the forward optimal operating point is used to achieve forward power transmission; for the reverse transmission path, the reverse optimal operating point is used to achieve reverse power transmission; for the idle path, the idle operating point is used.

[0030] In some specific embodiments of this application, the forward optimal operating point is specifically: the point at which the shift ratio and frequency ratio of the transmission path achieve soft switching of energy transmission within the full load range, while minimizing the sum of return power and current stress during energy transmission, under the premise of satisfying the preset rated transmission power; at the forward optimal operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is φ, and this phase difference φ is used as the optimal shift ratio D; At the reverse optimal operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to this transmission path is -φ. At the idle operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is 0.

[0031] In some specific embodiments of this application, based on the optimal operating point, the energy transmission direction of each transmission path is converted into a control signal, and the optimal active balancing of the battery pack group is achieved based on the control signal, including: Determine the direction of each transmission path: For a transmission path, if it is a forward transmission path, then the direction O of the transmission path is 1; if it is a reverse transmission path, then the direction O of the transmission path is -1; if it is an idle path, then the direction O of the transmission path is 0. Based on the optimal phase shift ratio D corresponding to the positive optimal operating point, the absolute phase shift time of each half-bridge drive signal is obtained according to the following formula. T i : in, T i Represents the i-th battery pack B i The absolute phase shift time corresponding to the half-bridge drive signal; T s For switching cycles; T i(i+1) Indicates the transmission path path i(i+1) The relative phase shift time between the two half-bridge drive signals corresponding to the two connected battery packs; The absolute phase shift time is used as a control signal, and the absolute phase shift time of each half-bridge drive signal is set based on this control signal to achieve optimal active balancing of the battery pack group.

[0032] Exemplary embodiments of this application, T 1 can be set to 0.

[0033] In the embodiments described above, this application uses imbalance energy AIE for drive control. The transmission path with smaller accumulated imbalance energy will complete equalization before the path with the largest accumulated imbalance energy. Once the largest accumulated imbalance is eliminated, the entire battery cluster achieves complete equalization, thus ensuring the theoretical convergence of the control strategy. Each path only transmits the minimum energy it requires (equal to the accumulated imbalance energy value of that path), greatly reducing unnecessary interactive energy flow, significantly reducing system energy loss, and improving equalization efficiency. The control logic is simplified by using AIE detection and direction vector allocation to transform the complex multi-objective equalization problem into simple direction judgment and operating point selection. The control logic is clear, concise, and easy to implement in engineering. It is compatible with the optimal operating point, fully leveraging the benefits of hardware parameter optimization, while achieving multiple advantages such as soft switching, low return current power, and low current stress.

[0034] Reference Figure 1 and Figure 2 The diagram shows a conventional AC2C type circuit equalization-switching multiplexing multiresonant switched capacitor equalization structure. This structure uses a half-bridge connected in parallel between each battery cell, enabling power transfer between adjacent cells. The structure has a total of n battery packs, where B... i Indicates the first i There are 1, 2, ..., n battery packs. n Each battery pack needs to be configured n Two and a half bridges, totaling 2 n A switching device, n- 1 L r , n- 1 C r Where Lr represents inductance and Cr represents capacitance. Specifically, each battery is connected in parallel with a half-bridge, for a total of n half-bridges. Each half-bridge contains an upper transistor and a lower transistor, where S... （2i-1） S (2i) These represent the upper and lower transistors of the parallel half-bridge of the i-th battery pack, respectively. The AC ports of each half-bridge are connected by the same parameters Lr and Cr.

[0035] Example 1: The implementation process of the active balancing strategy in this example is as follows: Figure 4 As shown, the specific steps are as follows: Step 1: Battery Pack Group Modeling For by n A group of battery packs consisting of unbalanced battery packs, with each pair of adjacent battery packs forming an energy transfer path, together form... n -1 transmission path; the energy range that each transmission path can transmit in each switching cycle is [- P max ·T s, P max ·T s ],in, P max The operating power can be determined by the optimal operating point parameters; T s One switching cycle; Step 2: Calculation of path transport energy For any transmission path path i(i+1) Its upstream battery pack (index ≤ i The accumulated imbalance energy (AIE) is equal to that of the downstream battery pack (index> i The accumulated unbalanced energy (energy that can only be transferred through this transmission path) is the minimum energy that this transmission path needs to transfer. E transmin,i(i+1) The AIE value of its upstream or downstream battery pack is calculated using the following formula: Among them, E pack,i For the i-th battery pack B i The actual remaining energy; E avg E represents the average energy of the battery pack group. im，i Let represent the unbalanced energy of the i-th battery pack, where i is the ordinal number of the battery pack (i.e., the series sequence). path i(i+1) Represents the i-th battery pack B i and the (i+1)th battery pack B i+1 The transmission path between them Indicates the transmission path path i(i+1) Minimum energy transmitted; E im，i For the i-th battery pack B i Unbalanced energy; AIE i This represents the cumulative value of the unbalanced energy from the first battery pack to the ith battery pack.

[0036] Step 3: Direction Vector Assignment Reference Figure 4 As shown, direction vectors are assigned to each transmission path based on the detected minimum transmission energy, O i(i+1) Indicates the transmission path path i(i+1) The direction vector value, T i For battery pack B iThe absolute phase shift time of the parallel half-bridge modules: If the minimum transmission energy is positive, the transmission path direction is marked as 1, and energy needs to be transmitted downstream; if the minimum transmission energy is negative, the transmission path direction is marked as -1, and energy needs to be transmitted in the opposite direction; if the minimum transmission energy is 0, the transmission path direction is marked as 0, and the path is idle. A direction column vector O' containing only 0, -1, and 1 elements can be generated based on the directions of all transmission paths.

[0037] Step 4: Modulation based on the optimal operating point The direction column vector O' is converted into specific control signals: the path with direction 1 uses the forward optimal operating point (phase difference φ = 0.1); the path with direction -1 uses the reverse optimal operating point (phase difference -0.1); the path with direction 0 is idle (phase difference 0). First, the direction column vector O' is multiplied by the optimal phase shift time. DT s The relative phase shift time between the two half-bridge drive signals corresponding to the two battery packs connected by a certain transmission path is obtained. T i(i+1) A relative phase shift time vector T can be generated based on the relative phase shift times of all transmission paths, and then the absolute phase shift time can be obtained through the transformation matrix H. T’ This enables precise control over transmission along each path: T’ =HT Where H is an n×n matrix; each element in T' is the absolute phase shift time corresponding to each transmission path.

[0038] The following will further illustrate the application of the structures and methods in the above embodiments with specific simulation examples.

[0039] Based on the above embodiments, the following simulation verification of the battery pack group is performed using MATLAB software. This embodiment involves an 8-cell series battery cluster and its active balancing system, comprising a total of 8 cells, 8 half-bridges, 16 switching devices, and 7... L r 7 C r The battery side has eight half-bridges connected in parallel, totaling 16 switching devices. The AC side of the half-bridges consists of seven... L r 7 C r Connect the batteries. The battery energy is randomly distributed, with per-unit values ​​of 5, 12, 3, 13, 5, 2, 8, and 4. The mathematical model of the AC2C active balancing system consisting of 8 batteries is as follows: Figure 5As shown. The maximum per-unit transmission power for each path is 0.001. The minimum equalization process interaction energy (i.e., the energy exchanged between all transmission paths during the entire equalization process) is calculated to be 22.

[0040] Figure 6 The diagram shows the energy change records of the eight batteries from unbalanced to balanced during the final energy balancing process, as well as the instantaneous average transmission power and total average power of all paths. Here, X represents the balancing time, and Y represents the average interaction power of all battery paths. The final total interaction energy is equal to the balancing time multiplied by the average total balancing interaction power of all paths, 700 * 0.031 = 22, achieving the minimum total energy required for path transmission and achieving an active balancing effect with low interaction capability. This application addresses the path overlap and frequent actions problems of existing adjacent-to-adjacent battery structural balancing topologies by proposing a path optimization method based on accumulated unbalanced energy detection. The core of this method lies in quantifying the global energy imbalance state of the system through mathematical calculation and automatically generating the optimal balancing command accordingly. This method is crucial for fully leveraging the performance advantages of AC2C topologies and improving the balancing efficiency and reliability of battery energy storage systems. This application uses vector form for global mathematical optimization instead of local comparisons or other intelligent control heuristics, fundamentally avoiding overlapping balancing paths, ensuring the minimum number of balancing path actions, achieving optimal path planning for balancing energy, and significantly improving balancing speed and system efficiency.

[0041] Based on the same inventive concept, another embodiment of this application provides a path-optimal active balancing system for adjacent battery coupling, referring to... Figure 7 As shown, the path-optimal active balancing system 100 includes: The acquisition module 110 is used to acquire the energy of each battery pack in the battery pack group and obtain the unbalanced energy of each battery based on the energy of the battery pack. The energy extraction module 120 is used to obtain the minimum energy of the transmission path between adjacent battery packs based on the unbalanced energy of the battery. Direction definition model 130 is used to determine the energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path; The working point allocation module 140 is used to allocate the corresponding optimal working point to each transmission path according to the energy transmission direction of the transmission path. The equalization module 150 is used to convert the energy transmission direction of each transmission path into a control signal based on the optimal operating point, and to achieve optimal active equalization of the battery pack group based on the control signal.

[0042] The above embodiments of this application, based on the balanced path structure from adjacent batteries to adjacent batteries, employ a cumulative unbalanced energy detection method and a path optimization method that uses the cumulative unbalanced energy to make path decisions, can ensure that the batteries are balanced without overlap and minimize the number of path actions, thereby achieving balanced energy path optimization.

[0043] It should be noted that the modules in the path-optimal active balancing system for adjacent battery coupling provided in the above embodiments of this application correspond to the steps of the path-optimal active balancing method for adjacent battery coupling in any of the above embodiments. Those skilled in the art can refer to the step features of the path-optimal active balancing method for adjacent battery coupling to implement the corresponding modules in the path-optimal active balancing system for adjacent battery coupling, which will not be repeated here.

[0044] In another embodiment of this application, a non-transitory computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the above-described path-optimal active balancing method for adjacent battery coupling.

[0045] In another embodiment of this application, an electronic device is also provided, including a memory and a processor; the memory is used to store program instructions; the processor is used to call the program instructions stored in the memory and execute the steps of the above-described path-optimal active balancing method for adjacent battery coupling according to the obtained program instructions.

[0046] Optionally, the memory is used to store programs; the memory may include volatile memory, such as random-access memory (RAM), such as static random-access memory (SRAM), double data rate synchronous dynamic random-access memory (DDR SDRAM), etc.; the memory may also include non-volatile memory, such as flash memory. The memory is used to store computer programs (such as application programs and functional modules that implement the above methods), computer instructions, etc., and the aforementioned computer programs and computer instructions can be partitioned and stored in one or more memories. Furthermore, the aforementioned computer programs, computer instructions, data, etc., can be accessed by the processor.

[0047] The aforementioned computer programs, computer instructions, etc., can be stored in partitions within one or more memory locations. Furthermore, the aforementioned computer programs, computer instructions, data, etc., can be accessed by a processor.

[0048] A processor is used to execute a computer program stored in memory to implement the various steps of the methods involved in the above embodiments. For details, please refer to the relevant descriptions in the preceding method embodiments.

[0049] The processor and memory can be separate structures or integrated structures. When the processor and memory are separate structures, they can be coupled together via a bus.

[0050] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application 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.

[0051] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. 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, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0052] 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, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0053] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0054] The preferred features in the above embodiments can be used individually in any embodiment, or in any combination thereof, provided they do not conflict with each other. Furthermore, parts not described in detail in the embodiments can be implemented using existing technologies.

[0055] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A path-optimal active balancing method for adjacent battery coupling, characterized in that, include: Collect the energy of each battery pack in the battery pack group, and obtain the unbalanced energy of each battery based on the energy of the battery pack; Based on the unbalanced energy of the battery, the minimum transmission energy of the transmission path between adjacent battery packs is obtained; Based on the minimum transmission energy of the transmission path, the energy transmission direction of each transmission path is determined; Based on the energy transmission direction of the transmission path, assign a corresponding optimal operating point to each transmission path; Based on the optimal operating point, the energy transmission direction of each transmission path is converted into a control signal, and the optimal active balancing of the battery pack group is achieved based on the control signal.

2. The path-optimal active balancing method for adjacent battery coupling according to claim 1, characterized in that, The unbalanced energy of the battery pack is the energy of the battery pack minus the average energy of the battery pack group.

3. The path-optimal active balancing method for adjacent battery coupling according to claim 1, characterized in that, For transmission path path i(i+1) The expression for its minimum transmission energy is as follows: in, path i(i+1) Represents the i-th battery pack B i and the (i+1)th battery pack B i+1 The transmission path between them Indicates the transmission path path i(i+1) Minimum energy transmitted; E im，i For the i-th battery pack B i The imbalance of energy.

4. The path-optimal active balancing method for adjacent battery coupling according to claim 1, characterized in that, Determining the energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path includes: For a transmission path, if its minimum transmission energy is greater than zero, then the transmission path is a forward transmission path; if its minimum transmission energy is less than zero, then the transmission path is a reverse transmission path; if its minimum transmission energy is equal to zero, then the transmission path is an idle path. The energy transmission direction of the forward transmission path is along the series arrangement of the battery packs, starting from the previous battery pack B. i Pointing to the next battery pack B i+1 The energy transmission direction of the reverse transmission path is along the series arrangement sequence of the battery packs, starting from the next battery pack B. i+1 Pointing to the previous battery pack B i There is no energy transfer between the two battery packs connected at both ends of the idle path.

5. The path-optimal active balancing method for adjacent battery coupling according to claim 4, characterized in that, The step of assigning an optimal operating point to each transmission path based on the energy transmission direction of the transmission path includes: For the forward transmission path, the forward optimal operating point is used to achieve forward power transmission; for the reverse transmission path, the reverse optimal operating point is used to achieve reverse power transmission; for the idle path, the idle operating point is used.

6. The path-optimal active balancing method for adjacent battery coupling according to claim 5, characterized in that, The positive optimal operating point is specifically defined as: the point at which the shift ratio and frequency ratio of the transmission path, under the premise of satisfying the preset rated transmission power, achieve soft switching of energy transmission within the full load range, while minimizing the sum of return power and current stress during energy transmission; at the positive optimal operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is φ, and this phase difference φ is taken as the optimal shift ratio D; At the reverse optimal operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is -φ. At the idle operating point, the phase difference between the two half-bridge drive signals corresponding to the two battery packs connected to the transmission path is 0.

7. The path-optimal active balancing method for adjacent battery coupling according to claim 5, characterized in that, The process of converting the energy transmission direction of each transmission path into a control signal based on the optimal operating point, and achieving optimal active balancing of the battery pack group based on the control signal, includes: Determine the direction of each transmission path: For each transmission path, if it is a forward transmission path, then the direction O of the transmission path is 1; if it is a reverse transmission path, then the direction O of the transmission path is -1; if it is an idle path, then the direction O of the transmission path is 0. Based on the optimal phase shift ratio D corresponding to the positive optimal operating point, the absolute phase shift time of each half-bridge drive signal is obtained according to the following formula. T i : in, T i Represents the i-th battery pack B i The absolute phase shift time corresponding to the half-bridge drive signal; T s For switching cycles; T i(i+1) Indicates the transmission path path i(i+1) The relative phase shift time between the two half-bridge drive signals corresponding to the two connected battery packs; The absolute phase shift time is used as a control signal, and the absolute phase shift time of each half-bridge drive signal is set based on this control signal to achieve optimal active balancing of the battery pack group.

8. A path-optimal active balancing system for adjacent battery coupling, characterized in that, include: The data acquisition module is used to collect the energy of each battery pack in the battery pack group and obtain the unbalanced energy of each battery based on the energy of the battery pack. The energy extraction module is used to obtain the minimum energy of the transmission path between adjacent battery packs based on the unbalanced energy of the battery. A direction definition model is used to determine the energy transmission direction of each transmission path based on the minimum transmission energy of the transmission path. The working point allocation module is used to allocate the corresponding optimal working point to each transmission path according to the energy transmission direction of the transmission path. The equalization module is used to convert the energy transmission direction of each transmission path into a control signal based on the optimal operating point, and to achieve optimal active equalization of the battery pack group based on the control signal.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method described in any one of claims 1-7.

10. An electronic device, characterized in that, include: At least one memory for storing program instructions; At least one processor is configured to invoke program instructions stored in the memory and execute the steps of the method described in any one of claims 1-7 according to the obtained program instructions.

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