Balancing structure of battery pack, battery pack and household energy storage device

Abstract

The utility model provides an equalization structure of a battery pack, the battery pack and a household energy storage device, the equalization structure of the battery pack comprises a plurality of battery modules, and each battery module comprises a plurality of single cells; the first switch array is used for controlling charging or discharging of the single battery cells needing to be equalized; the second switch array is used for controlling charging or discharging of the battery module needing to be equalized, and the problems that most of current battery equalization methods are used for equalizing batteries in battery packs, the battery packs are relatively independent physically, the voltage difference between the battery packs is large, series-parallel structures between the battery packs are complex and diversified, and the battery pack equalization efficiency is high are solved. The technical problem of difficulty in realizing inter-pack equalization is solved, and intra-pack and inter-pack equalization of the battery pack is realized.

Description

Technical Field

[0001] This utility model relates to the field of battery pack equalization management technology, specifically to a battery pack equalization structure and a battery pack and a household energy storage device. Background Technology

[0002] Battery packs are widely used in residential energy storage. The cells in a battery pack have differences in voltage, capacity, internal resistance, etc. As the usage time increases and the ambient temperature changes, the differences between cells gradually increase, resulting in low battery utilization and short battery life.

[0003] To address the above issues, most power battery systems used in residential energy storage employ balancing technology, which is divided into passive balancing technology and active balancing technology. Passive balancing technology typically uses resistors to dissipate excess energy in cells with excessively high voltage through heating. This method directly leads to a significant waste of energy and reduces the overall energy utilization rate of the battery pack.

[0004] Currently, active balancing technology mainly uses energy conversion devices such as capacitors, inductors, transformers, and redundant batteries to transfer energy from high-capacity batteries to low-capacity batteries, thereby achieving balance among individual cells.

[0005] However, electric vehicles require a large amount of battery energy, and their power battery systems are generally composed of multiple independent battery packs connected in series and parallel. Each battery pack is composed of several individual cells connected in series and parallel. Since most current battery balancing methods are aimed at balancing the cells within the battery pack, and the battery packs are physically relatively independent, the voltage difference between battery packs is large, and the series and parallel structures between battery packs are complex and diverse, it is difficult to achieve inter-pack balancing. Therefore, there is currently no mature inter-pack balancing solution.

[0006] Therefore, existing technologies still need further development. Utility Model Content

[0007] The purpose of this utility model is to overcome the above-mentioned technical deficiencies and provide a battery pack balancing structure, battery pack, and household energy storage device to solve the technical problem that most current battery balancing methods focus on balancing the batteries within the battery pack. The battery packs are physically relatively independent, the voltage difference between battery packs is large, and the series and parallel structures between battery packs are complex and diverse, making it difficult to achieve balancing between packs. Therefore, there is currently no mature inter-pack balancing solution.

[0008] To achieve the above-mentioned technical objectives, according to a first aspect of the present invention, the present invention provides a battery pack balancing structure, comprising:

[0009] Multiple battery modules, each battery module comprising multiple individual battery cells;

[0010] The first switch array is used to control the charging or discharging of individual battery cells that require equalization.

[0011] The second switch array is used to control the charging or discharging of battery modules that require equalization.

[0012] Specifically, the first switch array includes multiple electronically controlled switches, and the positive and negative terminals of the multiple individual battery cells are connected to the electronically controlled switches.

[0013] Specifically, the equalization structure of the battery pack also includes multiple in-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one in-group DC / DC bidirectional buck-boost converter. The battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding in-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding in-group DC / DC bidirectional buck-boost converter.

[0014] Specifically, multiple individual cells in each battery module are connected in series. The positive terminal of each individual cell is connected to the input terminal of the corresponding DC / DC bidirectional buck-boost converter in the battery module through an electronic control switch, and the negative terminal of each individual cell is connected to the output terminal of the corresponding DC / DC bidirectional buck-boost converter in the battery module through an electronic control switch, thus forming an electrical circuit.

[0015] Specifically, the equalization structure of the battery pack also includes multiple inter-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one inter-group DC / DC bidirectional buck-boost converter. The battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter.

[0016] Specifically, the multiple battery modules are connected in series, with the positive terminal of each battery module connected to the input terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter, and the negative terminal of each battery module connected to the output terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter, forming an electrical circuit.

[0017] Specifically, the second switch array includes two sets of MOSFETs, namely a charging MOSFET and a discharging MOSFET.

[0018] Specifically, the charging MOSFET includes a first charging MOSFET, and the discharging MOSFET includes a first discharging MOSFET, wherein the first charging MOSFET and the first discharging MOSFET are connected in parallel.

[0019] The source of the first charging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the drain of the first charging MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0020] Specifically, the drain of the first discharge MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the source of the first discharge MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0021] Specifically, the charging MOSFET includes a first charging MOSFET and a second charging MOSFET, and the discharging MOSFET includes a first discharging MOSFET and a second discharging MOSFET;

[0022] The source of the first charging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module. The drain of the first charging MOSFET is electrically connected to the source of the second charging MOSFET and the drain of the second discharging MOSFET, respectively. The drain of the second charging MOSFET and the source of the second discharging MOSFET are electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0023] Specifically, the drain of the first discharge MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, the source of the first discharge MOSFET is electrically connected to the drain of the second discharge MOSFET and the source of the second charge MOSFET, and the drain of the second discharge MOSFET and the source of the second charge MOSFET are electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0024] According to a second aspect of the present invention, a battery pack is provided, comprising:

[0025] The above-mentioned battery pack balancing structure.

[0026] According to a third aspect of this utility model, this utility model provides a residential energy storage device, comprising:

[0027] The aforementioned battery pack.

[0028] Beneficial effects:

[0029] This utility model provides a battery pack balancing structure, including multiple battery modules, each battery module including multiple individual cells; a first switch array for controlling the charging or discharging of the individual cells that need to be balanced; and a second switch array for controlling the charging or discharging of the battery modules that need to be balanced. This solves the technical problems that most current battery balancing methods only balance the batteries within the battery pack, the battery packs are physically relatively independent, the voltage difference between battery packs is large, the series and parallel structures between battery packs are complex and diverse, and the balancing between packs is difficult to achieve. This invention achieves balancing within and between battery packs. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the intra-group and inter-group balancing structure of the battery pack provided in a specific embodiment of this utility model;

[0031] Figure 2 This is a schematic diagram of the inter-group balancing structure of each battery module provided in a specific embodiment of this utility model;

[0032] Figure 3 This is a schematic diagram of the intra-group balancing module provided in a specific embodiment of this utility model;

[0033] Figure 4 This is a structural schematic diagram of the inter-group equalization charging and discharging process provided in a specific embodiment of this utility model. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solution of this utility model, the technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, the directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the creation of this utility model.

[0035] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0036] Example 1

[0037] Please see Figures 1-4 This embodiment provides a battery pack balancing structure, including:

[0038] Multiple battery modules, each battery module comprising multiple individual battery cells;

[0039] The first switch array is used to control the charging or discharging of individual battery cells that require equalization.

[0040] The second switch array is used to control the charging or discharging of battery modules that require equalization.

[0041] It should be noted that by using the above-mentioned device, the technical problems of most current battery balancing methods, which focus on balancing the batteries within the battery pack, and the large voltage difference between battery packs, the complex and diverse series and parallel structures between battery packs, and the difficulty in achieving inter-pack balancing, are solved, thus achieving both intra-pack and inter-pack balancing of the battery pack.

[0042] See Figure 3 In the equalization structure of the battery pack in this embodiment, the first switch array includes multiple electronically controlled switches, and the positive and negative terminals of the multiple individual battery cells are connected to the electronically controlled switches.

[0043] Furthermore, when a voltage difference between individual cells is detected, the corresponding electronic control switch of that individual cell is activated to form a closed loop.

[0044] See Figure 1 and Figure 3 In the equalization structure of the battery pack in this embodiment, the equalization structure of the battery pack further includes multiple intra-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one intra-group DC / DC bidirectional buck-boost converter. The battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter.

[0045] Furthermore, the in-group DC / DC bidirectional buck-boost converter is used to realize voltage buck-boost conversion within the battery module. Its basic function is to perform bidirectional energy transfer between individual cells in the battery module. It can not only transfer electrical energy from cells with higher voltage to cells with lower voltage (boost mode), but also transfer electrical energy to other cells with lower voltage when cells with higher voltage need to discharge (buck mode), thereby improving the energy utilization rate and cycle life of the entire battery pack.

[0046] See Figure 3 In the balanced structure of the battery pack in this embodiment, multiple individual cells in each battery module are connected in series. The positive terminal of each individual cell is connected to the input terminal of the DC / DC bidirectional buck-boost converter in the corresponding battery module through an electronic control switch, and the negative terminal of each individual cell is connected to the output terminal of the DC / DC bidirectional buck-boost converter in the corresponding battery module through an electronic control switch, thus forming an electrical circuit.

[0047] In this way, by controlling the electronically controlled switches in the first switch array (switch array 1), the cells that need to be balanced are connected to the DC / DC bidirectional buck-boost converter, so that the energy of a single cell can be transferred to the cells that need to be balanced through the DC / DC bidirectional buck-boost converter, thereby achieving voltage balance.

[0048] See Figure 1 and Figure 2 In the equalization structure of the battery pack in this embodiment, the equalization structure of the battery pack further includes multiple inter-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one inter-group DC / DC bidirectional buck-boost converter. The battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter.

[0049] The inter-module DC / DC bidirectional buck-boost converter is used to realize voltage boosting and bucking between battery modules. Through the interaction of fast switching and energy storage elements, it realizes efficient conversion and transmission of electrical energy. In the battery management system, the main function of the inter-module DC / DC bidirectional buck-boost converter is to maintain the voltage balance between battery modules and ensure that each module can operate in the best condition, thereby improving the energy utilization and safety of the entire battery system.

[0050] It is understandable that, since each battery module corresponds to an inter-module DC / DC bidirectional buck-boost converter, when the charge levels of different battery modules are different (for example, a certain module has a lower charge level), the inter-module DC / DC bidirectional buck-boost converter can convert the energy of the battery module with a higher charge level into a suitable voltage and then transmit it to the battery module with a lower charge level, thereby achieving inter-module balancing.

[0051] See Figure 2 In the equalization structure of the battery pack in this embodiment, the multiple battery modules are connected in series. The positive terminal of each battery module is connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to the battery module, and the negative terminal of each battery module is connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to the battery module, forming an electrical circuit.

[0052] Furthermore, in the above configuration, each battery module is connected to a corresponding inter-module DC / DC bidirectional buck-boost converter, enabling individual voltage adjustment for each battery module. During battery use, voltage imbalances may occur due to differences in the battery modules themselves (such as varying internal resistance). The DC / DC bidirectional buck-boost converter can lower the voltage of higher-voltage battery modules or raise the voltage of lower-voltage battery modules, thus maintaining a relatively balanced voltage across the battery modules. This helps improve the overall performance and lifespan of the battery pack. For example, during charging, if one battery module is nearly fully charged while others are not, the DC / DC bidirectional buck-boost converter can transfer excess energy to other modules. During discharging, if one module has a low charge level, it can also draw energy from other modules, thereby improving the overall energy utilization efficiency of the battery pack.

[0053] See Figure 2 In the equalization structure of the battery pack in this embodiment, the second switch array includes two sets of MOSFETs, namely a charging MOSFET and a discharging MOSFET.

[0054] The second switch array is... Figure 1 The switch array 2 in the system, by setting two sets of MOSFETs, namely charging MOSFETs and discharging MOSFETs, enables the system to achieve bidirectional energy flow control of the battery cells, improving balancing efficiency. By using the MOSFET array, the circuit structure can be simplified, the number of required components can be reduced, and modular design can be easily achieved, improving the maintainability and scalability of the system. By independently controlling each set of MOSFETs, the circuit can be quickly disconnected in abnormal situations to protect the battery cells from damage, thus improving the system's safety factor.

[0055] In the equalization structure of the battery pack in this embodiment, the charging MOSFET includes a first charging MOSFET, the discharging MOSFET includes a first discharging MOSFET, and the first charging MOSFET and the first discharging MOSFET are connected in parallel.

[0056] The source of the first charging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the drain of the first charging MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0057] The drain of the first discharge MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the source of the first discharge MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0058] Furthermore, the first charging MOSFET and the first discharging MOSFET are connected in parallel, allowing current to flow between the two MOSFETs during charging and discharging, thus enabling bidirectional energy transfer. During charging, the first charging MOSFET is turned on, allowing excess energy from one battery module to be transferred to another module with a lower voltage via a DC / DC bidirectional buck-boost converter. During discharging, the first discharging MOSFET plays a similar role, transferring energy from the module with a higher voltage to the module with a lower voltage.

[0059] See Figure 2 In the equalization structure of the battery pack in this embodiment, the charging MOSFET includes a first charging MOSFET and a second charging MOSFET, and the discharging MOSFET includes a first discharging MOSFET and a second discharging MOSFET.

[0060] The source of the first charging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module. The drain of the first charging MOSFET is electrically connected to the source of the second charging MOSFET and the drain of the second discharging MOSFET, respectively. The drain of the second charging MOSFET and the source of the second discharging MOSFET are electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0061] In the above configuration, the drain of the first charging MOSFET (Qn_2) is connected to the source of the second charging MOSFET (Qn_3) and the drain of the second discharging MOSFET (Qn_4), forming a path that allows current to flow from one battery module to another through these two MOSFETs. The dual-MOSFET structure provides a safer protection mechanism. For example, when one MOSFET fails, the other MOSFET can cut off the current to prevent overcharging or over-discharging, thereby protecting the battery and the circuit. The two MOSFETs can distribute the workload, reduce the heat generated by individual devices, and help improve the thermal stability of the system and extend the service life of the equipment.

[0062] The drain of the first discharge MOSFET (Qn_1) is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to a battery module. The source of the first discharge MOSFET is electrically connected to the drain of the second discharge MOSFET (Qn_4) and the source of the second charge MOSFET (Qn_3), respectively. The drain of the second discharge MOSFET and the source of the second charge MOSFET are electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

[0063] In the battery pack balancing structure of this embodiment, the charging MOSFET may consist only of a first charging MOSFET, and the discharging MOSFET may consist only of a first discharging MOSFET. The first charging MOSFET and the first discharging MOSFET are connected in parallel. The source of the first charging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the drain of the first charging MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module. The drain of the first discharging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the source of the first discharging MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module. This allows current to flow between the two MOSFETs during charging and discharging, realizing bidirectional energy transfer.

[0064] In the battery pack balancing structure of this embodiment, the charging MOSFET may include only a first charging MOSFET and a second charging MOSFET, and the discharging MOSFET may include only a first discharging MOSFET and a second discharging MOSFET. The source of the first charging MOSFET is electrically connected to the output terminal of an inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module. The drain of the first charging MOSFET is electrically connected to the source of the second charging MOSFET and the drain of the second discharging MOSFET, respectively. The drain of the second charging MOSFET and the source of the second discharging MOSFET are electrically connected to the output terminal of an inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module. Similarly, the drain of the first discharging MOSFET is electrically connected to the output terminal of an inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module. The source of the first discharging MOSFET is electrically connected to the drain of the second discharging MOSFET and the source of the second charging MOSFET, respectively. The drain of the second discharging MOSFET and the source of the second charging MOSFET are electrically connected to the output terminal of an inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module. See also... Figure 4 Modules 1, 3, and 4 are discharged through an inter-group DC / DC bidirectional buck-boost converter, while modules 2 and 5 are charged through the same converter. The voltages of modules 1, 3, and 4 are used to reduce the SOC of the battery modules that need to be balanced to the average SOC among all modules through the inter-group DC / DC bidirectional buck-boost converter. Modules 2 and 5 are used to increase the SOC of the battery modules that need to be balanced to the average SOC among all modules through the same converter.

[0065] It should be noted that this embodiment provides a battery pack balancing structure, including multiple battery modules, each battery module including multiple individual cells; a first switch array for controlling the charging or discharging of the individual cells that need to be balanced; and a second switch array for controlling the charging or discharging of the battery modules that need to be balanced. This solves the technical problem that most current battery balancing methods only balance the batteries within a battery pack, and that battery packs are physically relatively independent, have large voltage differences between battery packs, and have complex and diverse series and parallel structures between battery packs, making it difficult to achieve inter-pack balancing. This embodiment achieves both intra-pack and inter-pack balancing of the battery pack.

[0066] Example 2

[0067] This embodiment provides a battery pack, including: the equalization structure of the battery pack in Embodiment 1.

[0068] Specifically, the battery pack's balancing structure includes:

[0069] Multiple battery modules, each battery module comprising multiple individual battery cells;

[0070] The first switch array is used to control the charging or discharging of individual battery cells that need to be balanced. The first switch array includes multiple electronically controlled switches, and the positive and negative terminals of multiple individual battery cells are connected to the electronically controlled switches.

[0071] The second switch array is used to control the charging or discharging of battery modules that require equalization.

[0072] Specifically, the battery pack's balancing structure also includes multiple intra-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one intra-group DC / DC bidirectional buck-boost converter. Each battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter. Multiple individual cells within each battery module are connected in series. The positive terminal of each individual cell is connected to the input terminal of the corresponding intra-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, and the negative terminal of each individual cell is connected to the output terminal of the corresponding intra-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, forming an electrical circuit.

[0073] Specifically, the battery pack's balancing structure also includes multiple inter-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one inter-group DC / DC bidirectional buck-boost converter. Each battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter. Multiple individual cells within each battery module are connected in series. The positive terminal of each individual cell is connected to the input terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, and the negative terminal of each individual cell is connected to the output terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, forming an electrical circuit.

[0074] It should be noted that this embodiment provides a battery pack with a balancing structure, including multiple battery modules, each of which includes multiple individual battery cells; a first switch array; and a second switch array. This addresses the technical challenges of current battery balancing methods, which primarily balance batteries within a single battery pack. These methods are characterized by the relative independence of battery packs, significant voltage differences between battery packs, and complex series-parallel connections, making inter-pack balancing difficult. This embodiment achieves both intra-pack and inter-pack balancing. Based on inter-pack balancing, the overall charging and discharging efficiency of the battery pack is improved because balanced inter-pack voltages reduce energy loss during inter-pack transfer, enabling more efficient charging and discharging operations and improving energy utilization efficiency. In practical applications, such as electric vehicles, this can extend driving range or reduce charging time.

[0075] Example 3

[0076] This embodiment provides a residential energy storage device, including: the battery pack in Embodiment 2.

[0077] Specifically, the aforementioned battery pack can be applied to residential energy storage devices. The balancing structure of the battery pack includes: multiple battery modules, each battery module including multiple individual cells; a first switch array for controlling the charging or discharging of the individual cells that need to be balanced, the first switch array including multiple electronically controlled switches, and the positive and negative terminals of the multiple individual cells are connected to electronically controlled switches; and a second switch array for controlling the charging or discharging of the battery modules that need to be balanced.

[0078] Specifically, the battery pack's balancing structure also includes multiple intra-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one intra-group DC / DC bidirectional buck-boost converter. Each battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter. Multiple individual cells within each battery module are connected in series. The positive terminal of each individual cell is connected to the input terminal of the corresponding intra-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, and the negative terminal of each individual cell is connected to the output terminal of the corresponding intra-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, forming an electrical circuit.

[0079] Specifically, the battery pack's balancing structure also includes multiple inter-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one inter-group DC / DC bidirectional buck-boost converter. Each battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter. Multiple individual cells within each battery module are connected in series. The positive terminal of each individual cell is connected to the input terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, and the negative terminal of each individual cell is connected to the output terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter via an electronically controlled switch, forming an electrical circuit.

[0080] It should be noted that this embodiment provides a residential energy storage device, which includes a battery pack and adopts a battery pack balancing structure, including multiple battery modules, each battery module including multiple individual cells; a first switch array, and a second switch array. This solves the technical problem that most current battery balancing methods only balance the batteries within the battery pack, and that battery packs are physically relatively independent, have large voltage differences between battery packs, and have complex and diverse series and parallel structures between battery packs, making it difficult to achieve inter-pack balancing. This embodiment achieves both intra-pack and inter-pack balancing of the battery pack.

[0081] Furthermore, residential energy storage devices can store electrical energy more efficiently. For example, when a solar power system is used in conjunction with a residential energy storage device, the electricity generated during the day can be stored more effectively. Due to the balanced battery pack, energy loss during storage is reduced, improving overall storage efficiency and enabling households to better utilize renewable energy. This is because residential energy storage devices may undergo frequent charge-discharge cycles. By reducing damage to the battery cells caused by uneven charging and discharging, the lifespan of the entire energy storage device can be significantly extended, reducing replacement costs for home users. Since household appliances have varying power requirements, from low-power smart home devices to high-power appliances such as air conditioners and water heaters, a balanced battery pack can stably provide power according to the needs of these devices, preventing insufficient power supply or voltage fluctuations caused by imbalances within or between battery packs.

[0082] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0083] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A battery pack balancing structure, characterized in that, include: Multiple battery modules, each battery module comprising multiple individual battery cells; The first switch array is used to control the charging or discharging of individual battery cells that require equalization. The second switch array is used to control the charging or discharging of battery modules that require equalization. The first switch array includes multiple electronically controlled switches, and the positive and negative terminals of the multiple individual battery cells are connected to the electronically controlled switches; The equalization structure of the battery pack also includes multiple intra-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one intra-group DC / DC bidirectional buck-boost converter. The battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding intra-group DC / DC bidirectional buck-boost converter.

2. The equalization structure of the battery pack according to claim 1, characterized in that, Multiple individual cells in each battery module are connected in series. The positive terminal of each individual cell is connected to the input terminal of the corresponding DC / DC bidirectional buck-boost converter in the battery module through an electronic control switch. The negative terminal of each individual cell is connected to the output terminal of the corresponding DC / DC bidirectional buck-boost converter in the battery module through an electronic control switch, forming an electrical circuit.

3. The equalization structure of the battery pack according to claim 1, characterized in that, The equalization structure of the battery pack also includes multiple inter-group DC / DC bidirectional buck-boost converters. Each battery module corresponds to one inter-group DC / DC bidirectional buck-boost converter. The battery module includes an input terminal and an output terminal. The input terminal of the battery module is electrically connected to the output terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter, and the output terminal of the battery module is electrically connected to the input terminal of its corresponding inter-group DC / DC bidirectional buck-boost converter.

4. The equalization structure of the battery pack according to claim 3, characterized in that, The multiple battery modules are connected in series. The positive terminal of each battery module is connected to the input terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter, and the negative terminal of each battery module is connected to the output terminal of the corresponding inter-group DC / DC bidirectional buck-boost converter, forming an electrical circuit.

5. The equalization structure of the battery pack according to claim 4, characterized in that, The second switch array includes two sets of MOSFETs, namely a charging MOSFET and a discharging MOSFET.

6. The equalization structure of the battery pack according to claim 5, characterized in that, The charging MOSFET includes a first charging MOSFET, and the discharging MOSFET includes a first discharging MOSFET. The first charging MOSFET and the first discharging MOSFET are connected in parallel. The source of the first charging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the drain of the first charging MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

7. The equalization structure of the battery pack according to claim 6, characterized in that, The drain of the first discharge MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module, and the source of the first discharge MOSFET is electrically connected to the input terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

8. The equalization structure of the battery pack according to claim 5, characterized in that, The charging MOSFET includes a first charging MOSFET and a second charging MOSFET, and the discharging MOSFET includes a first discharging MOSFET and a second discharging MOSFET; The source of the first charging MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module. The drain of the first charging MOSFET is electrically connected to the source of the second charging MOSFET and the drain of the second discharging MOSFET, respectively. The drain of the second charging MOSFET and the source of the second discharging MOSFET are electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

9. The equalization structure of the battery pack according to claim 8, characterized in that, The drain of the first discharge MOSFET is electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to one battery module. The source of the first discharge MOSFET is electrically connected to the drain of the second discharge MOSFET and the source of the second charge MOSFET, respectively. The drain of the second discharge MOSFET and the source of the second charge MOSFET are electrically connected to the output terminal of the inter-group DC / DC bidirectional buck-boost converter corresponding to another battery module.

10. A battery pack, characterized in that, include: The balanced structure of the battery pack according to any one of claims 1-9.

11. A household energy storage device, characterized in that, include: The battery pack of claim 10.

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