Battery pack active equalization system and electronic equipment

Abstract

The invention provides an active equalization system for a battery pack. The active equalization system comprises a plurality of battery modules, an acquisition module, a control module and a BMS module, each battery module is connected to the inter-group equalization bus; the acquisition module is configured to acquire battery information of each battery module and upload the battery information to the BMS module; the BMS module is configured to generate a control instruction based on the battery information and issue the control instruction to the control module; and the control module is configured to control the corresponding battery module to perform inter-group energy equalization through the inter-group equalization bus based on the control instruction. According to the embodiment of the invention, the situation that a transformer winding is directly connected to a common alternating current bus to serve as a port for realizing inter-group equalization is avoided, an external power supply is not needed for energy transfer, the defects of long alternating current path, high loss, strong interference and the like are overcome, and the energy transmission efficiency during active equalization of the battery is effectively improved.

Description

Technical Field

[0001] The present application belongs to the field of power electronics, and in particular, relates to a battery pack active balancing system and electronic equipment. Background Art

[0002] A battery pack is composed of many battery cells connected in series or in parallel and then in series. Due to various factors such as the inconsistency defects in the manufacturing process of the battery cells themselves, the different operating temperatures of batteries in different positions, battery aging, and changes in internal resistance, it is easy for the battery cells to be unbalanced, especially for batteries that have been used for a period of time or retired batteries. If they continue to be used, the "short board effect" will appear, that is, the discharge amount of the battery pack is determined by the battery cell with the smallest power, which not only affects the battery life of the entire battery pack, but also the battery cell with the smallest power may be over-discharged or over-charged, causing irreversible damage to the battery or even safety hazards. For this reason, it is necessary to balance the battery cells.

[0003] According to the different ways of handling mismatch energy, battery balancers can be divided into two categories: passive balancing (energy consumption balancing) and active balancing (non-energy consumption balancing). Among them, active balancing technology can effectively utilize the full power and capacity of the battery pack, with high overall efficiency and strong balancing ability, and is the main development direction of energy balancing technology in the future. Modular active balancing technology is widely used in large-scale battery series energy storage system applications due to its advantages such as fast balancing speed, high efficiency, and strong scalability. However, the related technology directly uses the transformer winding to connect to the common AC bus as the port for achieving inter-group balancing, which will lead to problems such as long AC path, large loss, strong interference, etc., and requires an external power supply for energy transfer, and cannot achieve direct single-cell transmission. Summary of the invention

[0004] The embodiments of the present application provide a battery pack active balancing system and an electronic device, aiming to solve the problem of low energy transmission efficiency during active balancing of batteries in the related art.

[0005] In order to solve the above technical problems, the first aspect of the embodiment of the present application provides a battery pack active balancing system, comprising a plurality of battery modules, a collection module, a control module and a BMS module, and each of the battery modules is connected to an inter-group balancing bus; the battery module also includes a battery pack, a matrix switch circuit and a bidirectional isolation converter; the battery pack includes a plurality of single cells connected in series, and each of the single cells is connected to a first port of the bidirectional isolation converter through the matrix switch circuit; the second port of the bidirectional isolation converter is connected to two ends of the battery pack, and the third port of the bidirectional isolation converter is connected to the inter-group balancing bus;

[0006] The acquisition module includes a plurality of acquisition boards, and the acquisition boards are configured to acquire battery information of corresponding battery modules and upload the battery information to the BMS module; wherein the battery information of the battery module includes battery information of each of the single cells;

[0007] The BMS module is configured to generate a control instruction based on the battery information and send the control instruction to the control module;

[0008] The control module includes multiple balancing controllers, and the balancing controllers are configured to control the connection status of the matrix switch circuit and the bidirectional isolation converter port based on the control instructions, so as to control the corresponding battery modules to perform inter-group energy balancing through the inter-group balancing bus, and control the corresponding battery modules to perform intra-group energy balancing between the single battery and the battery group where the battery single is located.

[0009] In one embodiment, the matrix switch circuit includes a matrix switch and a matrix switch bus; the battery pack is electrically connected to the matrix switch bus through the matrix switch, and the positive and negative ends of the matrix switch bus are electrically connected to the first port of the bidirectional isolation converter.

[0010] In one embodiment, both ends of each of the single cells are electrically connected to the matrix switch bus through a bidirectional switch in the matrix switch; wherein the number of the bidirectional switches connected to the matrix switch bus is twice the number of single cells in the battery pack.

[0011] In one embodiment, it also includes a polarity switching circuit; each series node between the single cells is electrically connected to the polarity switching circuit through a single switch in the matrix switch, and the polarity switching circuit is electrically connected to the matrix switch bus; wherein the number of the bidirectional switches connected to the matrix switch bus is the number of single cells in the battery pack plus one.

[0012] In one embodiment, the bidirectional isolation converter includes an isolation transformer, which is electrically connected to the matrix switch bus through a first port of the bidirectional isolation converter, the isolation transformer is electrically connected to two ends of the battery group through a second port of the bidirectional isolation converter, and the isolation transformer is electrically connected to the inter-group balancing bus through a third port of the bidirectional isolation converter; wherein the ports are bridge circuits, and the windings of the isolation transformer are connected to the midpoint of the bridge circuit.

[0013] In one embodiment, the bridge circuit is connected to the winding of the isolation transformer via an LC network; wherein the inductance in the LC network is a transformer leakage inductance or an external inductance.

[0014] In one embodiment, the BMS module is further configured to determine the single battery to be balanced based on the battery information, generate a first control instruction and send the first control instruction to the corresponding balancing controller;

[0015] The balancing controller is further configured to control the third port of the bidirectional isolation converter to be disconnected based on the first control instruction, and control the matrix switch to select the single cell to be balanced, so as to achieve intra-group energy balancing between the single cell to be balanced and the battery group where the single cell to be balanced is located.

[0016] In one embodiment, the BMS module is further configured to determine the single battery to be balanced based on the battery information, generate a second control instruction and send the second control instruction to the corresponding balancing controller;

[0017] The balancing controller is further configured to control the second port of the bidirectional isolation converter to be disconnected based on the second control instruction, and control the matrix switch to select the single cell to be balanced, so as to achieve energy balancing between the single cell to be balanced and the battery group other than the battery group where the single cell to be balanced is located.

[0018] In one embodiment, the BMS module is further configured to determine a battery group to be balanced based on the battery information, generate a third control instruction and send the third control instruction to the corresponding balancing controller;

[0019] The balancing controller is also configured to control all the matrix switches to be disconnected based on the third control instruction, and control the connection status of the second port and the third port of the bidirectional isolation converter to achieve energy balancing between the battery group to be balanced and the other battery groups.

[0020] A second aspect of the present application provides an electronic device, the electronic device comprising a battery pack active balancing system as described in any one of the above.

[0021] The battery pack active balancing system provided in the embodiment of the present application collects the battery information of each battery module through the acquisition module, and uploads the battery information to the BMS module, and then the BMS module generates a control instruction based on the battery information, and sends the control instruction to the control module, and finally the control module controls the corresponding battery module to perform inter-group energy balancing through the inter-group balancing bus based on the control instruction. The embodiment of the present application avoids directly using the transformer winding connected to the public AC bus as a port for achieving inter-group balancing, and does not require an external power supply for energy transfer, overcoming the defects of long AC path, large loss, strong interference, etc., and effectively improving the energy transmission efficiency during active battery balancing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the related technologies or the embodiments of the present application, the drawings required for use in the description of the related technologies or the embodiments of the present application will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, not all embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of a battery pack active balancing system provided in the first aspect of the embodiment of the present application;

[0024] Figure 2 A structural schematic diagram of a detailed battery pack active balancing system provided in the first aspect of the embodiment of the present application;

[0025] Figure 3 A circuit structure diagram of a matrix switch circuit provided in the first aspect of the embodiment of the present application;

[0026] Figure 4 A schematic diagram of a matrix switch circuit structure using a double matrix switch provided in the first aspect of the embodiment of the present application;

[0027] Figure 5 A schematic diagram of a matrix switch circuit structure using a single matrix switch provided in the first aspect of the embodiment of the present application;

[0028] Figure 6 A schematic diagram of the structure of a battery module provided in the first aspect of the embodiment of the present application;

[0029] Figure 7 A circuit diagram of a first-port bridge circuit provided in the first aspect of an embodiment of the present application;

[0030] Figure 8 A schematic diagram of a second port or third port bridge circuit provided in the first aspect of the embodiment of the present application;

[0031] Fig. 9 A schematic diagram of the structure of another battery pack active balancing system provided in the first aspect of the embodiment of the present application;

[0032] Fig.10 A schematic diagram of the structure of an electronic device provided in accordance with the second aspect of an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0035] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means one or more, unless otherwise clearly and specifically defined.

[0037] Figure 1 A schematic diagram of the structure of a battery pack active equalization system provided in the first aspect of an embodiment of the present application is shown. For the sake of convenience, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0038] The battery pack active balancing system in this embodiment includes a plurality of battery modules 101, a collection module 102, a control module 103 and a BMS module 104, and each battery module is connected to an inter-group balancing bus 105;

[0039] The acquisition module 102 is configured to acquire battery information of each battery module 101 and upload the battery information to the BMS module 104;

[0040] The BMS module 104 is configured to generate control instructions based on the battery information and send the control instructions to the control module 103;

[0041] The control module 103 is configured to control the corresponding battery module 101 to perform inter-group energy balancing through the inter-group balancing bus 105 based on the control instruction, and control the corresponding battery module to perform intra-group energy balancing between the single battery and the battery group where the battery single is located.

[0042] Specifically, the entire battery pack active balancing system includes multiple battery modules connected in series, each battery module is connected to the component balancing bus, the acquisition module collects the battery information of each battery module, and uploads the battery information to the BMS module, the BMS module performs balancing analysis based on the collected battery information, determines whether there is energy imbalance between the battery modules, and if energy balancing is required, determines the battery module to be balanced, and generates a control instruction to transmit to the control module, and the control module controls the connection status of the corresponding battery module based on the control instruction, so that each battery module performs energy balancing between groups through the component balancing bus. It can be understood that when balancing between groups, at least one battery module discharges to the inter-group balancing bus, and at the same time at least one battery module draws power from the inter-group balancing bus.

[0043] The battery pack active balancing system provided in the embodiment of the present application collects the battery information of each battery module through the acquisition module, and uploads the battery information to the BMS module, and then the BMS module generates a control instruction based on the battery information, and sends the control instruction to the control module, and finally the control module controls the corresponding battery module to perform inter-group energy balancing through the inter-group balancing bus based on the control instruction. The embodiment of the present application avoids directly using the transformer winding connected to the public AC bus as a port for achieving inter-group balancing, and does not require an external power supply for energy transfer, overcoming the defects of long AC path, large loss, strong interference, etc., and effectively improving the energy transmission efficiency during active battery balancing.

[0044] exist Figure 1 Based on the battery pack active balancing system provided, this embodiment also provides a detailed structural schematic diagram of the battery pack active balancing system, for details, please refer to Figure 2 In some embodiments, the battery module includes a battery pack 1011, a matrix switch circuit 1012 and a bidirectional isolation converter 1013; the battery pack 1011 includes a plurality of single cells connected in series, each of which is connected to a first port of the bidirectional isolation converter 1013 through the matrix switch circuit 1012; the second port of the bidirectional isolation converter 1013 is connected to two ends of the battery pack 1011, and the third port of the bidirectional isolation converter 1013 is connected to an inter-group balancing bus 105;

[0045] The acquisition module includes a plurality of acquisition boards, and the acquisition board 1021 is configured to acquire battery information of the corresponding battery module 1011 and upload the battery information to the BMS module 104; wherein the battery information of the battery module 1011 includes battery information of each single battery;

[0046] The control module includes multiple balancing controllers, and the balancing controller 1031 is configured to control the connection status of the matrix switch circuit 1012 and the bidirectional isolation converter 1013 port based on the control instruction, so as to control the corresponding battery module 1011 to perform inter-group energy balancing through the inter-group balancing bus 105, and control the corresponding battery module 1011 to perform intra-group energy balancing between the single cells and the battery group.

[0047] Specifically, each battery module also includes a battery pack, which is composed of a plurality of battery cells connected in series and is connected to the first port of the bidirectional isolation converter through a matrix switch circuit. When the BMS module analyzes the collected battery information and obtains that the energy of a single battery in the battery pack is greater than that of other batteries, it is necessary to perform energy balancing on the single battery. At this time, the BMS module will send a control instruction to the control module, wherein the balancing controller in the control module in this embodiment is an MCU as shown in the figure. The balancing controller MCU will control the matrix switch circuit to switch the switch state corresponding to the single battery that needs energy balancing according to the control instruction, so that the single battery is connected to the bidirectional isolation converter, and then the balancing controller MCU will also control the bidirectional isolation converter to access the second port or the third port, and transmit the energy back to the two ends of the entire battery string through the second port, or transmit the energy to the inter-group balancing bus through the third port, thereby finally realizing the energy balancing from the single battery to the entire battery pack, or realizing the energy balancing between the single battery and other battery modules. It is understandable that, in the same way, when the energy of a single battery is smaller than that of other batteries, the energy of the entire battery string is reversely transmitted to the second port of the bidirectional isolation converter, and then the energy is finally transmitted to the single battery to be balanced through the first port of the bidirectional isolation converter and the selection of the matrix switch circuit. It is understandable that when the battery groups are balanced, at least one converter discharges to the inter-group balancing bus, and at least one converter draws power from the inter-group balancing bus.

[0048] This embodiment also provides a circuit structure diagram of a matrix switch circuit. For details, see Figure 3 In some embodiments, the matrix switch circuit includes a matrix switch and a matrix switch bus; the battery pack is electrically connected to the matrix switch bus through the matrix switch, and the positive and negative ends of the matrix switch bus are electrically connected to the first port of the bidirectional isolation converter.

[0049] Specifically, the series battery string is connected to the matrix switch bus through a matrix switch, the positive and negative ends of the matrix switch bus are respectively connected to the two ends of the first port of the bidirectional isolation converter, and the second port of the bidirectional isolation converter is connected back to the two ends of the battery pack. The matrix switch is directly connected to the first port of the bidirectional isolation converter through the matrix switch bus, without the need to use a polarity switching circuit and a high-frequency isolation converter switch, so that the number of switch tubes on the current path is reduced, reducing the hardware cost. Furthermore, the current on the low-voltage side of the transformer is large, and the current path is shortened by canceling the polarity switching switch and the high-frequency switch of the traditional converter, so that the energy loss is reduced. It can be understood that the matrix switch can adopt a double switch form or a single switch form. When a double switch is adopted, the matrix switch bus voltage is unipolar and is not affected by the number and position of the connected single battery cells. When a single switch is adopted, the bus voltage polarity is related to the position of the connected battery cell. The specific situation will be described in detail in the subsequent steps.

[0050] Furthermore, if Figure 4 The figure shows a schematic diagram of a matrix switch circuit structure using a double matrix switch provided in the first aspect of the embodiment of the present application. In some embodiments, both ends of each single cell in the battery string are electrically connected to the matrix switch bus through a bidirectional switch in the matrix switch; wherein the number of bidirectional switches connected to the matrix switch bus is twice the number of single cells in the battery pack.

[0051] Specifically, when double switches are used, both ends of each single battery are connected to the matrix switch bus through a bidirectional switch. The number of bidirectional switches on the matrix switch bus in a single battery string is twice the number of battery cells. The bus voltage is unipolar, showing positive or negative polarity, and is not affected by the position of the connected battery cell. Therefore, there is no need to use a polarity switching circuit, which shortens the current path and reduces the path loss of energy.

[0052] Furthermore, if Figure 5 The diagram shows a schematic diagram of a matrix switch circuit structure using a single matrix switch provided in the first aspect of the embodiment of the present application. In some embodiments, a polarity switching circuit is also included; each series node between single cells is electrically connected to the polarity switching circuit through a single switch in the matrix switch, and the polarity switching circuit is electrically connected to the matrix switch bus; wherein the number of bidirectional switches connected to the matrix switch bus is the number of single cells in the battery pack plus one.

[0053] Specifically, when a single switch is used, each series node of a single battery is connected to the matrix switch bus in sequence through a bidirectional switch. The number of bidirectional switches on the matrix switch bus in a single battery string is the number of battery cells plus one, and the bus voltage polarity is related to the position of the connected battery cell. Figure 5 As shown, when the matrix switch SL5 and matrix switch S L4 When the matrix switch S is connected to balance the battery cells, the bus voltage of the matrix switch is positive at the top and negative at the bottom. L4 and matrix switch S L3 When the battery cells are connected for balancing, the voltage of the matrix switch bus is negative at the top and positive at the bottom. Therefore, we connect a polarity switching circuit between the matrix switch bus and the first port of the bidirectional isolation converter to change the voltage polarity. Through the polarity switching circuit, the voltage polarity of the matrix switch bus is always positive at the top and negative at the bottom or positive at the bottom and negative at the top.

[0054] like Figure 6 The figure shows a schematic diagram of the structure of a battery module provided by the first aspect of the embodiment of the present application. The bidirectional isolation converter includes an isolation transformer, the isolation transformer is electrically connected to the matrix switch bus through the first port of the bidirectional isolation converter, the isolation transformer is electrically connected to the two ends of the battery pack through the second port of the bidirectional isolation converter, and the isolation transformer is electrically connected to the inter-group balancing bus through the third port of the bidirectional isolation converter; wherein the port is a bridge circuit, and the winding of the isolation transformer is connected to the midpoint of the bridge circuit.

[0055] Furthermore, in some optional embodiments, the bridge circuit is connected to the winding of the isolation transformer via an LC network; wherein the inductance in the LC network is the transformer leakage inductance or an external inductance.

[0056] It can be understood that, due to the existence of a matrix switch circuit between the first port of the bidirectional isolation converter and the battery cells in the battery pack, the first port can be completely disconnected by the matrix switch, so the bridge circuit connected to the first port can adopt a traditional full-bridge or traditional half-bridge structure, and the positive and negative ends of the second port of the transformer in the bidirectional isolation converter are respectively connected to the two ends of the entire battery pack to achieve balanced transmission of energy in the entire battery pack, and the third port of the transformer in the bidirectional isolation transformer is connected to the inter-group balancing bus, so that the current entire battery module, or a battery cell in the battery module, can achieve inter-group energy balancing with other battery modules. In addition, an LC network can be added between the bridge circuit and the isolation converter winding according to actual needs, which can be a single inductor element or a single capacitor element, or an LC combination, etc., wherein the inductor can be a transformer leakage inductance or an external inductor, and the specific elements and parameters are determined according to actual needs. For example, Figure 7 The circuit diagram of the first port bridge circuit is given. Figure 8 A schematic diagram of a bridge circuit of the second port or the third port is provided. In the bridge circuit, the switch tube or capacitor may be changed according to actual needs, and the embodiment of the present application does not specifically limit this.

[0057] In some embodiments, the BMS module is further configured to determine the single battery to be balanced based on the battery information, generate a first control instruction and send the first control instruction to the corresponding balancing controller;

[0058] The balancing controller is also configured to control the third port of the bidirectional isolation converter to be disconnected based on the first control instruction, and control the matrix switch to select the single cell to be balanced, so as to achieve energy balancing within the battery group where the single cell to be balanced is located.

[0059] Specifically, when the bidirectional switch of the third port is disconnected, the battery cell to be balanced is selected through the matrix switch, so that energy can be transmitted between the battery cell and the battery pack. In detail, the acquisition board will first collect the parameter information of each single battery in the battery pack, including the current working parameters of the battery such as the remaining power state, and then upload the relevant information to the BMS module for analysis to detect whether there is an imbalance in energy between batteries. For example, if the power of one single battery is higher than that of other batteries, the BMS will send a control instruction to the corresponding balancing controller MCU in the control module, and the corresponding balancing controller MCU will control the connection state of the matrix switch in the corresponding battery module and the connection state of the bidirectional isolation converter according to the control instruction. Among them, the corresponding first control instruction in this embodiment will control the matrix switch to select a single cell with too high power, and control the first port to be turned on, and the second and third ports to be disconnected, so that the single cell charges the primary winding of the converter. After the charging is completed, the first port is disconnected and the third port is kept disconnected, and then the second port is connected, so that the energy is transmitted from the secondary winding through the second port to the positive and negative ends of the entire battery pack, and finally the energy of the single cell is balanced among the battery modules to which it belongs. When the power of one of the single cells is too low, the opposite is true.

[0060] In some embodiments, the BMS module is further configured to determine the single battery to be balanced based on the battery information, generate a second control instruction and send the second control instruction to the corresponding balancing controller;

[0061] The balancing controller is also configured to control the second port of the bidirectional isolation converter to be disconnected based on the second control instruction, and control the matrix switch to select the single cell to be balanced, so as to achieve energy balancing between the single cell to be balanced and the battery group outside the battery group where the single cell to be balanced is located.

[0062] In some embodiments, the BMS module is further configured to determine the battery group to be balanced based on the battery information, generate a third control instruction and send the third control instruction to the corresponding balancing controller;

[0063] The balancing controller is also configured to control all matrix switches to be disconnected based on a third control instruction, and to control the connection state of the second port and the third port of the bidirectional isolation converter to achieve energy balancing between the battery group to be balanced and other battery groups.

[0064] Similarly, the second control instruction corresponds to the energy transmission between the single cell and another battery module, and the third control instruction corresponds to the energy transmission between the entire battery module and another battery module. The specific principle is the same as in the step corresponding to the first control instruction above, and will not be repeated here. Therefore, this system can realize any transmission between "this group of single cells to this group of batteries", "this group of single cells to another group of single cells", "this group of batteries to another group of single cells", and "this battery group to another battery group". It can balance multiple modules at the same time, and it can also realize that multiple modules charge and discharge a single module at the same time, making the balancing method of active battery balancing more flexible, faster, more efficient, and more reliable when combined with multiple balancing methods.

[0065] In addition, each battery module balancing circuit can work independently and simultaneously when performing "single cell to group" balancing within the group. When performing inter-group balancing, at least one battery or battery group discharges to the inter-group balancing bus, and at least one battery or battery group charges through the inter-group balancing bus. Moreover, when performing inter-group balancing, multiple batteries or battery groups can charge and discharge a single battery or battery group.

[0066] Optionally, when the direct single-unit transmission working mode is not required, the second port can also be a common bridge structure, and by controlling the matrix switch and the bidirectional switch of the third port, the energy can be balanced within the group between the first port and the second port, or between the group between the second port and the third port.

[0067] Optionally, when there is no need to transmit the working mode between battery packs, the second port and the third port can reuse the winding and the converter and switch through an external switch. At this time, the bridge circuit corresponding to the second and third ports can adopt a traditional half-bridge or full-bridge structure.

[0068] like Fig. 9 As shown, in some optional embodiments, when there is no need to transmit the working mode between battery packs, the second port and the third port can reuse the windings and converters and switch through an external switch. At this time, the bridge circuits corresponding to the second and third ports can adopt a traditional half-bridge or full-bridge structure.

[0069] The battery pack active balancing system provided in the embodiment of the present application collects the battery information of each battery module through the acquisition module, and uploads the battery information to the BMS module, and then the BMS module generates a control instruction based on the battery information, and sends the control instruction to the control module, and finally the control module controls the corresponding battery module to perform inter-group energy balancing through the inter-group balancing bus based on the control instruction. The embodiment of the present application avoids directly using the transformer winding connected to the common AC bus as a port for achieving inter-group balancing, and does not require an external power supply for energy transfer, overcomes the defects of long AC path, large loss, strong interference, etc., and effectively improves the energy transmission efficiency during active battery balancing. In addition, the system can achieve simultaneous balancing of multiple modules, and can also achieve simultaneous charging and discharging of a single module by multiple modules, so that the balancing method of active battery balancing is more flexible, the balancing speed is faster, the balancing efficiency is higher, and the combination of multiple balancing methods has higher reliability.

[0070] Fig.10 A schematic diagram of an electronic device provided in the second aspect of an embodiment of the present application is shown. As shown in the figure, the second aspect of an embodiment of the present application provides an electronic device A, and the electronic device A includes a battery pack active balancing system 10 as any one of the above items.

[0071] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0072] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0073] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A battery pack active balancing system, characterized in that: The invention comprises a plurality of battery modules, a collection module, a control module and a BMS module, and each of the battery modules is connected to an inter-group balancing bus; the battery module further comprises a battery pack, a matrix switch circuit and a bidirectional isolation converter; the battery pack comprises a plurality of single cells connected in series, and each of the single cells is connected to a first port of the bidirectional isolation converter through the matrix switch circuit; the second port of the bidirectional isolation converter is connected to two ends of the battery pack, and the third port of the bidirectional isolation converter is connected to the inter-group balancing bus; The acquisition module includes a plurality of acquisition boards, and the acquisition boards are configured to acquire battery information of corresponding battery modules and upload the battery information to the BMS module; wherein the battery information of the battery module includes battery information of each of the single cells; The BMS module is configured to generate a control instruction based on the battery information and send the control instruction to the control module; The control module includes multiple balancing controllers, and the balancing controllers are configured to control the connection status of the matrix switch circuit and the bidirectional isolation converter port based on the control instructions, so as to control the corresponding battery modules to perform inter-group energy balancing through the inter-group balancing bus, and control the corresponding battery modules to perform intra-group energy balancing between the single cells and the battery group.

2. The battery pack active balancing system as claimed in claim 1, characterized in that: The matrix switch circuit includes a matrix switch and a matrix switch bus; the battery pack is electrically connected to the matrix switch bus through the matrix switch, and the positive and negative ends of the matrix switch bus are electrically connected to the first port of the bidirectional isolation converter.

3. The battery pack active balancing system as claimed in claim 2, characterized in that: Both ends of each of the single cells are electrically connected to the matrix switch bus through a bidirectional switch in the matrix switch; wherein the number of the bidirectional switches connected to the matrix switch bus is twice the number of the single cells in the battery pack.

4. The battery pack active balancing system as claimed in claim 2, characterized in that: It also includes a polarity switching circuit; each series node between the single cells is electrically connected to the polarity switching circuit through a single switch in the matrix switch, and the polarity switching circuit is electrically connected to the matrix switch bus; wherein the number of the bidirectional switches connected to the matrix switch bus is the number of single cells in the battery pack plus one.

5. The battery pack active balancing system as claimed in claim 3, characterized in that: The bidirectional isolation converter includes an isolation transformer, which is electrically connected to the matrix switch bus through a first port of the bidirectional isolation converter, the isolation transformer is electrically connected to two ends of the battery group through a second port of the bidirectional isolation converter, and the isolation transformer is electrically connected to the inter-group balancing bus through a third port of the bidirectional isolation converter; wherein the ports are bridge circuits, and the windings of the isolation transformer are connected to the midpoint of the bridge circuit.

6. The battery pack active balancing system as claimed in claim 5, characterized in that: The bridge circuit is connected to the winding of the isolation transformer via an LC network; wherein the inductance in the LC network is the transformer leakage inductance or the external inductance.

7. The battery pack active balancing system according to any one of claims 5, characterized in that: The BMS module is further configured to determine the single battery to be balanced based on the battery information, generate a first control instruction and send the first control instruction to the corresponding balancing controller; The balancing controller is further configured to control the third port of the bidirectional isolation converter to be disconnected based on the first control instruction, and control the matrix switch to select the single cell to be balanced, so as to achieve intra-group energy balancing between the single cell to be balanced and the battery group where the single cell to be balanced is located.

8. The battery pack active balancing system as claimed in claim 5, characterized in that: The BMS module is further configured to determine the single battery to be balanced based on the battery information, generate a second control instruction and send the second control instruction to the corresponding balancing controller; The balancing controller is further configured to control the second port of the bidirectional isolation converter to be disconnected based on the second control instruction, and control the matrix switch to select the single cell to be balanced, so as to achieve energy balancing between the single cell to be balanced and the battery group other than the battery group where the single cell to be balanced is located.

9. The battery pack active balancing system as claimed in claim 5, characterized in that: The BMS module is further configured to determine a battery group to be balanced based on the battery information, generate a third control instruction and send the third control instruction to the corresponding balancing controller; The balancing controller is also configured to control all the matrix switches to be disconnected based on the third control instruction, and control the connection status of the second port and the third port of the bidirectional isolation converter to achieve energy balancing between the battery group to be balanced and the other battery groups.

10. An electronic device, characterized in that: The electronic device comprises a battery pack active balancing system as claimed in any one of claims 1 to 9.

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