Battery system and energy adjusting method
By setting up an energy regulation circuit inside the battery pack casing, energy transfer between multiple battery cells is realized, solving the problem of energy imbalance among battery cells, improving the modular expansion capability and energy transfer efficiency of the battery pack, and reducing system complexity and cost.
Patent Information
- Application Number
- CN202511352187.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-01-24
- Filing Date
- 2025-09-19
- Publication Date
- 2026-02-10
AI Technical Summary
In existing technologies, energy imbalance when multiple battery cells are connected in series leads to a decrease in overall capacity, and modular expansion of battery packs is difficult to achieve. Existing energy balancing solutions are complex, costly, and have low reliability.
Design a battery system in which an energy regulation circuit is located inside the battery pack housing and connects to other battery packs through connection terminals on the housing to realize energy transfer between multiple battery cells. Energy storage elements, switching circuits and transmission lines are used to coordinate energy flow, and energy balance is achieved by using a battery pack controller and a main control unit.
It improves the modular expansion capability of the battery pack, reduces system complexity and cost, and improves energy transfer efficiency and reliability.
Smart Images
Figure CN121508035A_ABST
Abstract
Description
Cross-references to related applications
[0001] This application is based on and claims priority to Chinese Patent Application No. 202510121867.0, filed on January 24, 2025, the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application belongs to the field of battery technology, and in particular relates to a battery system and energy regulation method. Background Technology
[0003] In energy storage systems, multiple battery cells are typically connected in series. If the energy distribution among the individual battery cells is uneven, the overall capacity will decrease due to the "weakest link" effect.
[0004] Existing energy balancing methods typically involve adding full-power converters or using isolated bus configurations, which are complex, costly, and unreliable. Furthermore, in stacked structures, expanding or removing battery packs usually requires additional wiring, hindering modular expansion of the battery packs. Summary of the Invention
[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a battery system and energy regulation method that improves the modular expansion capability of the battery pack while enabling energy transfer between multiple battery cells.
[0006] In a first aspect, this application provides a battery system including multiple battery packs, each battery pack comprising: The housing has a positive terminal, a negative terminal and at least one energy transmission terminal. The battery cell is housed inside the casing, with the positive terminal of the battery cell connected to the positive terminal and the negative terminal of the battery cell connected to the negative terminal. An energy regulation circuit is disposed inside the housing. The energy regulation circuit is connected to the energy transmission terminal and the battery cell. The energy regulation circuit is configured to transmit the energy input from the energy transmission terminal to the battery cell and to output the energy from the battery cell from the energy transmission terminal. The battery packs are interconnected via positive terminals, negative terminals, and energy transfer terminals.
[0007] According to one embodiment of this application, the energy regulation circuit includes: An energy storage element, the first end of which is connected to the first terminal of the battery cell; The switching circuit is connected to the second terminal of the battery cell, the second terminal of the energy storage element, and the energy transmission terminal, respectively. The switching circuit is configured to conduct the power transmission path between the second terminal of the battery cell and the second terminal of the energy storage element, or to conduct the power transmission path between the second terminal of the energy storage element and the energy transmission terminal. The transmission line has its first end connected to the first end of the energy storage element and its second end connected to the energy transmission terminal.
[0008] According to one embodiment of this application, the energy storage element is an inductor, and the first terminal of the inductor is connected to the first terminal of the battery cell. The switching circuit includes: The first switch has its first terminal connected to the second terminal of the battery cell, and its second terminal connected to the second terminal of the inductor. The second switch has its first end connected to the second end of the first switch and the second end of the inductor, and its second end connected to the energy transmission terminal.
[0009] According to one embodiment of this application, the energy transmission terminal includes a first energy transmission terminal and a second energy transmission terminal, the first energy terminal being connected to a second end of the transmission line, and the second energy transmission terminal being connected to a second end of a second switch.
[0010] According to one embodiment of this application, the transmission line is directly connected between the first energy terminal and the first pole of the battery cell.
[0011] According to one embodiment of this application, the housing is further provided with a control signal terminal, and the battery pack further includes: The battery pack controller is electrically connected to the control signal terminal, the drive terminal of the first switch, and the drive terminal of the second switch, respectively, and is configured to drive the first switch with a first pulse signal and drive the second switch with a second pulse signal, wherein the duty cycle of the first pulse signal and the duty cycle of the second pulse signal are complementary.
[0012] According to one embodiment of this application, the first end of the transmission line is disposed between the first terminal of the battery cell and the first end of the energy storage element, and the battery pack further includes: The current detection circuit has a first sampling node and a second sampling node. The first sampling node is located between the first pole of the battery cell and the first end of the transmission line, and the second sampling node is located between the first end of the transmission line and the first end of the energy storage element. The current detection circuit is configured to determine the current flowing through the battery pack based on the sampled current of the first sampling node and / or the second sampling node.
[0013] According to one embodiment of this application, a control signal terminal is provided on the housing of the battery pack, and the battery pack also includes a battery pack controller, which is connected to the battery cell, the energy regulation circuit and the control signal terminal respectively. The battery system also includes a main control unit, which is electrically connected to the control signal terminals of each battery pack and configured to communicate with the battery pack controller.
[0014] Secondly, this application provides an energy regulation method applied to a battery system according to the aforementioned battery system, the battery system including a first battery pack and a second battery pack, the negative terminal of the first battery pack being connected to the positive terminal of the second battery pack, and the energy transmission terminal of the first battery pack being connected to the energy transmission terminal of the second battery pack, the energy regulation method including: Obtain energy from the first and second battery cells; The energy control and regulation circuit, based on the energy of the first and second battery cells, transfers energy between the first and second battery packs.
[0015] According to one embodiment of this application, an energy control and energy regulation circuit based on the energy of the first battery cell and the second battery cell performs energy transfer between the first battery pack and the second battery pack, including: When the first energy of the first battery cell is less than the second energy of the second battery cell, and the absolute value of the difference between the first energy and the second energy is greater than a preset threshold, the second energy regulation circuit is controlled to transfer the target energy in the second battery cell to the first energy regulation circuit, and the first energy regulation circuit is controlled to transfer the target energy to the first battery cell. When the first energy of the first battery cell is greater than the second energy of the second battery cell, and the absolute value of the difference between the first energy and the second energy is greater than a preset threshold, the first energy regulation circuit is controlled to transfer the energy in the first battery cell to the second energy regulation circuit, and the second energy regulation circuit is controlled to transfer the target energy to the second battery cell.
[0016] According to one embodiment of this application, the battery packs in the battery system are connected in series, and the energy regulation circuit includes a first equalization line and a second equalization line. The first equalization line is used to connect to the battery cells in the next battery pack, and the second equalization line is used to connect to the battery cells in the previous battery pack. The energy regulation method further includes: Obtain the total current of the battery system; During the energy transfer process, the first average current on the first equalization line and the second average current on the second equalization line are determined. The actual current flowing through the battery cells in its own battery pack is obtained by superimposing the total current, the first average current, and the second average current.
[0017] According to one embodiment of this application, a first equalization circuit includes an energy storage element, a first switch, and a second switch. A first terminal of the energy storage element is connected to a first terminal of both the first and second switches. A second terminal of the first switch is connected to the positive terminal of a battery cell. A second terminal of the energy storage element is connected to the negative terminal of the battery cell. A second terminal of the second switch is used to connect to a battery cell in a next battery pack. Determining a first average current on the first equalization circuit includes: Determine the third average current of the first line between the second terminal of the energy storage element and the negative terminal of the battery cell; The first average current is determined according to the following formula: I bat_b =I S_b *D1=I S_b *(1-D2) Among them, I bat_b I is the first average current. S_b D1 is the third average current, D2 is the duty cycle of the drive signal of the first switch, D2 is the duty cycle of the drive signal of the second switch, and D1+D2≤1.
[0018] According to one embodiment of this application, the first end of the second balancing circuit is connected to the first circuit. The first circuit includes a second circuit connected between the negative terminal of the battery cell and the first end of the second balancing circuit, and a third circuit connected between the first end of the second balancing circuit and the second end of the energy storage element. The actual current is determined according to the following formula: I bat =I bat_S +I S -I L *D2 Among them, I bat For the actual current, I bat_S For the total current, I S I is the average current of the second line. L This represents the average current of the third line.
[0019] According to several embodiments of the battery system and energy regulation method of this application, the energy regulation circuit is disposed inside the housing of the battery pack and can be connected to the energy regulation circuits in other battery packs through the connection terminals on the housing to realize energy transfer between multiple battery cells. The terminals on the battery pack housing facilitate the detachable connection of multiple battery packs, thereby improving the modular expansion capability of the battery pack.
[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0021] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is one of the structural schematic diagrams of energy balancing circuits in related technologies; Figure 2 This is the second schematic diagram of the energy balancing circuit in related technologies; Figure 3 This is a schematic diagram of the battery pack structure provided in the embodiments of this application; Figure 4 This is one of the circuit diagrams of the battery pack provided in the embodiments of this application; Figure 5 This is a second circuit diagram of the battery pack provided in the embodiments of this application; Figure 6 This is one of the circuit diagrams of the battery system provided in the embodiments of this application; Figure 7 This is a second circuit diagram of the battery system provided in the embodiments of this application; Figure 8 This is a schematic diagram of the sampling structure of the battery system provided in an embodiment of this application; Figure 9 This is a schematic diagram of the switch drive signal waveform and inductor current waveform provided in the embodiments of this application; Figure 10A This is one of the energy balance diagrams provided in the embodiments of this application; Figure 10B This is the second schematic diagram of energy balance provided in the embodiments of this application; Figure 11A This is the third schematic diagram of energy balance provided in the embodiments of this application; Figure 11B This is the fourth schematic diagram of energy balance provided in the embodiments of this application; Figure 12 This is one of the flowcharts of the energy regulation method provided in the embodiments of this application; Figure 13 This is the second flowchart of the energy regulation method provided in the embodiments of this application; Figure 14 This is the third flowchart of the energy regulation method provided in the embodiments of this application; Figure 15 This is the fourth flowchart of the energy regulation method provided in the embodiments of this application.
[0022] Figure label: Battery pack 100, housing 110, battery unit 120, energy regulation circuit 130, battery pack controller 140, main control unit 150, first to second switches K1~K2, inductor L, positive terminal P1, negative terminal P2, energy transmission terminal Q, control signal terminal COM, first to second energy transmission terminals Q1~Q2. Detailed Implementation
[0023] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0024] In the following description, a "circuit" refers to a conductive loop consisting of at least one element or sub-circuit connected by an electrical or electromagnetic link. When an element or circuit is said to be "coupled to" or "connected to" another element, or when an element / circuit is said to be "coupled at" or "connected at" two nodes, it can be directly coupled to or connected to the other element, or there may be intermediate elements. The connection between elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there are no intermediate elements between them.
[0025] In the description, the terms "first," "second," etc., are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that such numerical descriptors can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0026] Furthermore, the use of terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicates that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0027] In energy storage systems, multiple battery cells are typically connected in series. If the energy distribution among the individual battery cells is uneven, the overall capacity will decrease due to the "weakest link" effect.
[0028] Reference Figure 1 and Figure 2 In related technologies, energy balancing circuits typically employ the addition of a full-power converter ( Figure 1 As shown), or using an isolated bus configuration ( Figure 2 As shown in the figure, it is complex, costly, and has low reliability. Furthermore, in a stacked structure, when expanding or removing parts of the battery pack, additional connections are usually required, making modular expansion of the battery pack impossible.
[0029] This application proposes a battery system and energy regulation method. The energy regulation circuit is located inside the battery pack housing and can be connected to the energy regulation circuits in other battery packs through the connection terminals on the housing to realize energy transfer between multiple battery cells. The terminals on the battery pack housing facilitate the detachable connection of multiple battery packs, improving the modular expansion capability of the battery pack.
[0030] One embodiment of this application discloses a battery system comprising multiple battery packs 100, which can be connected in series or in parallel. The connections between the battery packs 100 are achieved through terminals, facilitating expansion.
[0031] Reference Figure 3 , Figure 3 The structure of a battery pack 100 provided in an embodiment of this application is shown. In this embodiment, the battery pack 100 includes: a housing 110, battery cells 120, and an energy regulation circuit 130. The housing 110 is provided with a positive terminal P1, a negative terminal P2, and at least one energy transmission terminal Q; the battery cells 120 are disposed within the housing 110, with the positive terminal of the battery cells 120 connected to the positive terminal P1 and the negative terminal of the battery cells 120 connected to the negative terminal P2; the energy regulation circuit 130 is disposed within the housing 110 and is connected to the energy transmission terminal Q and the battery cells 120. The energy regulation circuit 130 is configured to transmit energy input from the energy transmission terminal Q to the battery cells 120 and to output energy from the battery cells 120 via the energy transmission terminal Q. Each battery pack 100 is interconnected via the positive terminal P1, the negative terminal P2, and the energy transmission terminal Q.
[0032] The housing 110 is the external structure of the entire battery pack 100, primarily used to ensure the safety of internal components and provide necessary electrical isolation and physical protection. The housing 110 has multiple interfaces, including a positive terminal P1, a negative terminal P2, and at least one energy transfer terminal Q. The energy transfer terminal Q is mainly used for energy input and output, providing an energy transfer path for energy transfer between the battery pack 100 and the outside world. The number of energy transfer terminals Q can be selected according to the actual application scenario and is not limited here. For example, there can be one or two energy transfer terminals Q.
[0033] Battery cell 120 is disposed within battery pack housing 110 and is primarily used for storing and providing energy. Battery cell 120 may contain multiple battery cells connected in series or in parallel. The positive terminal of battery cell 120 is connected to the positive terminal P1 on housing 110, and the negative terminal is connected to the negative terminal P2. In a stacked structure, the positive terminal of battery pack 100 can be connected to the negative terminal of adjacent battery pack 100, and the energy transmission terminals Q on battery pack 100 are interconnected, enabling multiple battery cells 120 to be connected in series.
[0034] The energy regulation circuit 130 is mainly used to coordinate the energy flow between the battery cell 120 and the energy transmission terminal Q. The energy regulation circuit 130 is connected to the battery cell 120 and the energy transmission terminal Q, and is configured to perform both energy input and energy output functions. Its energy input function is manifested in that when external electrical energy is input to the battery pack 100 through the energy transmission terminal Q, the energy regulation circuit 130 can effectively control the charging process of the battery cell 120, transferring the input energy to the battery cell 120, ensuring that the current and voltage remain within a safe range during the charging process, and achieving efficient charging of the battery cell 120. Its energy output function is manifested in that when the battery cell 120 needs to provide energy to external devices, the energy regulation circuit 130 is responsible for outputting the energy stored in the battery cell 120 through the energy transmission terminal Q.
[0035] The energy regulation circuit 130 is located inside the housing 110 and is connected to the energy transmission terminals Q of other battery packs 100 via energy transmission terminals Q. In the stacked structure, the battery pack 100 can receive energy from the battery packs 100 connected to it via the energy transmission terminals Q, and can also transmit energy to the battery packs 100 connected to it via the energy transmission terminals Q, thereby realizing energy transfer between multiple battery packs 100.
[0036] The battery packs 100 are interconnected through the positive terminal P1, the negative terminal P2 and the energy transmission terminal Q. When expanding or removing part of the battery pack 100, it is only necessary to connect or disconnect the terminals, which facilitates the modular expansion of the battery pack 100.
[0037] The positive terminal P1 of battery pack 100 is connected to the negative terminal P2 of the adjacent battery pack 100, and the negative terminal P2 of battery pack 100 is connected to the positive terminal P1 of another adjacent battery pack 100. The first energy transmission terminal Q1 of battery pack 100 is connected to the second energy transmission terminal Q2 of the adjacent battery pack 100, and the second energy transmission terminal Q2 of battery pack 100 is connected to the first energy transmission terminal Q1 of the adjacent battery pack 100. Energy can be transferred between the battery cells 120 through the energy transmission terminals Q.
[0038] According to the battery pack 100 of this application, the energy regulation circuit 130 is disposed inside the housing 110 of the battery pack 100, and can be connected to the energy regulation circuit 130 in other battery packs 100 through the connection terminals on the housing 110 to realize energy transfer between multiple battery cells 120. The terminals on the battery pack housing 110 facilitate the detachable connection of multiple battery packs 100, thereby improving the modular expansion capability of the battery pack 100.
[0039] In some embodiments, the energy regulation circuit 130 includes an energy storage element, a switching circuit, and a transmission line. A first terminal of the energy storage element is connected to a first terminal of the battery cell 120; the switching circuit is connected to a second terminal of the battery cell 120, a second terminal of the energy storage element, and an energy transmission terminal Q, respectively. The switching circuit is configured to either connect the energy transmission path between the second terminal of the battery cell 120 and the second terminal of the energy storage element, or connect the energy transmission path between the second terminal of the energy storage element and the energy transmission terminal Q; a first terminal of the transmission line is connected to the first terminal of the energy storage element, and a second terminal of the transmission line is connected to the energy transmission terminal Q.
[0040] The energy storage element is primarily used to store the energy output from the battery cell 120, as well as the energy input through the energy transfer terminal Q. The specific type of energy storage element can be selected based on the actual application scenario and is not limited here. For example, the energy storage element can be an inductor L.
[0041] The switching circuit is mainly used to control the flow of electrical energy. It is connected to the second terminal of the battery cell 120, the second terminal of the energy storage element, and the energy transmission terminal Q, allowing adjustment of the energy transmission path as needed. When the switching circuit first connects the energy transmission path between the second terminal of the battery cell 120 and the second terminal of the energy storage element, the battery cell 120 can charge the energy storage element. After charging is complete, the switching circuit connects the energy transmission path between the second terminal of the energy storage element and the energy transmission terminal Q, enabling the energy storage element to provide energy to external loads or other circuits; that is, the electrical energy from the battery cell 120 can be output through the energy transmission terminal Q.
[0042] Conversely, when the switching circuit first connects the energy transmission path between the second terminal of the energy storage element and the energy transmission terminal Q, the energy storage element can be charged by an external load or other circuits. After the charging process is completed, the switching circuit connects the energy transmission path between the second terminal of the battery cell 120 and the second terminal of the energy storage element, so that the energy storage element can charge the battery cell 120, that is, the energy input by the energy transmission terminal Q can be used to charge the battery cell 120.
[0043] It should be noted that the specific objects referred to by the first electrode and the second electrode of battery cell 120 can be selected according to the actual application scenario, and are not limited here. When the first electrode of battery cell 120 is positive, the second electrode of battery cell 120 is negative; when the first electrode of battery cell 120 is negative, the second electrode of battery cell 120 is positive.
[0044] The transmission line is electrically connected between the first end of the energy storage element and the energy transmission terminal Q. The first end of the energy storage element is connected to the first pole of the battery cell 120. The transmission line is mainly used to realize the energy transfer between the energy transmission terminal Q and the first pole of the battery cell 120.
[0045] It should be noted that within the same battery pack 100, the transmission line and the switching circuit are typically not simultaneously activated. The switching circuit is primarily used to facilitate energy transfer between the battery cell 120 and the energy storage element, while the transmission line, via the energy transfer terminal Q, facilitates energy transfer between external energy and the battery cell 120. When the second end of the transmission line and the switching circuit are connected to the same energy transfer terminal Q, a switch can be installed on the transmission line to prevent the transmission line and the switching circuit from activating simultaneously.
[0046] In some embodiments, the energy storage element is an inductor L, with its first end connected to the first terminal of the battery cell 120. The switching circuit includes a first switch K1 and a second switch K2. The first end of the first switch K1 is connected to the second terminal of the battery cell 120, and its second end is connected to the second end of the inductor L. The first end of the second switch K2 is connected to both the second end of the first switch K1 and the second end of the inductor L, and its second end is connected to the energy transmission terminal Q.
[0047] The specific types of the first switch K1 and the second switch K2 can be selected according to the actual application scenario, and are not limited here. For example, the first switch K1 and the second switch K2 can be MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or IGBT (Insulated Gate Bipolar Transistor).
[0048] Reference Figure 4 , Figure 4 The circuitry within a battery pack 100 provided in an embodiment of this application is illustrated. As an example, the first terminal of the battery cell 120 can be a positive terminal, the second terminal of the battery cell 120 can be a negative terminal, and the energy storage element is an inductor L. The first terminal of the inductor L is electrically connected to the positive terminal of the battery cell 120, and the first terminal of the first switch K1 is connected to the negative terminal of the battery cell 120. In one energy transfer cycle, if the first switch K1 is turned on first and the second switch K2 is turned off, the battery cell 120 charges the inductor L. After the inductor L is fully charged, the second switch K2 is turned on and the first switch K1 is turned off, allowing the energy stored in the inductor L to be transferred to the outside of the battery pack 100 via the energy transfer terminal Q. If the second switch K2 is turned on first and the first switch K1 is turned off, energy from outside the battery pack 100 can charge the inductor L via the energy transfer terminal Q. After the inductor L is fully charged, the first switch K1 is turned on and the second switch K2 is turned off, allowing the inductor L to transfer electrical energy to the battery cell 120.
[0049] Reference Figure 5 , Figure 5 The circuitry within a battery pack 100 provided in an embodiment of this application is illustrated. As another example, the first terminal of the battery cell 120 can be a negative terminal, the second terminal of the battery cell 120 can be a positive terminal, and the energy storage element is an inductor L. The first end of the inductor L is electrically connected to the negative terminal of the battery cell 120, and the first end of the first switch K1 is connected to the positive terminal of the battery cell 120. In this embodiment, the switching sequence and energy transfer path within one energy transfer cycle can refer to the aforementioned embodiments, and will not be repeated here.
[0050] In some embodiments, the energy transmission terminal Q includes a first energy transmission terminal Q1 and a second energy transmission terminal Q2. The first energy terminal is connected to the second end of the transmission line, and the second energy transmission terminal Q2 is connected to the second end of the second switch K2.
[0051] The transmission line is electrically connected between the first energy terminal and the first end of the inductor L, and the second switch K2 is electrically connected between the second energy transmission terminal Q2 and the second end of the inductor L. That is, the transmission line and the switching circuit are connected to different energy transmission terminals Q, which facilitates independent control of the transmission line and the switching circuit.
[0052] In some embodiments, the transmission line is directly connected between the first energy terminal and the first pole of the battery cell 120.
[0053] The transmission line is mainly used to provide an energy transfer path for energy transfer between interconnected battery packs 100, forming a complete loop. Therefore, when the transmission line and the switching circuit are connected to different energy transfer terminals Q, there is no need to install switches or other devices on the transmission line, which can save circuit costs and reduce losses caused by components.
[0054] In some embodiments, the housing 110 is further provided with a control signal terminal COM, and the battery pack 100 further includes a battery pack controller 140. The battery pack controller 140 is electrically connected to the control signal terminal COM, the driving terminal of the first switch K1, and the driving terminal of the second switch K2, respectively, and is configured to drive the first switch K1 with a first pulse signal and drive the second switch K2 with a second pulse signal. The duty cycle of the first pulse signal and the duty cycle of the second pulse signal are complementary.
[0055] The battery pack controller 140 can be implemented using an MCU (Microcontroller Unit) chip; it can also be implemented based on a DSP (Digital Signal Processor) chip, an FPGA (Field-Programmable Gate Array), or a custom controller chip; the embodiments of this application do not limit the specific hardware implementation of the controller.
[0056] The battery pack controller 140 is mainly used to apply drive signals to the first switch K1 and the second switch K2 through the control signal terminal COM, so as to drive the first switch K1 and the second switch K2 to turn on or off. The first pulse signal and the second pulse signal can be PWM (Pulse Width Modulation) signals.
[0057] The duty cycle of the first pulse signal is complementary to that of the second pulse signal, that is, the first switch K1 and the second switch K2 are complementary in conduction, thereby realizing the uninterrupted alternation of charging and discharging of inductor L, improving energy transfer efficiency.
[0058] In some embodiments, the first end of the transmission line is disposed between the first pole of the battery cell 120 and the first end of the energy storage element. The battery pack 100 further includes a current detection circuit having a first sampling node and a second sampling node. The first sampling node is disposed between the first pole of the battery cell 120 and the first end of the transmission line, and the second sampling node is disposed between the first end of the transmission line and the first end of the energy storage element. The current detection circuit is configured to determine the current flowing through the battery pack 100 based on the sampling current of the first sampling node and / or the second sampling node.
[0059] The current detection circuit is used to detect the current in the battery pack 100 during the energy equalization process, in order to monitor the energy changes during the energy equalization process. Specifically, the first sampling node is mainly used to detect the current flowing from the negative terminal of the battery cell 120 to the first end of the transmission line, and the second sampling node is mainly used to detect the current flowing from the inductor L at the first end of the transmission line. The current detection circuit transmits the detection results to the battery pack controller 140, enabling the battery pack controller 140 to monitor the energy transfer status in real time and achieve more precise control based on the actual situation.
[0060] Furthermore, when the battery system outputs energy, the battery pack controller 140 can also combine the total current of the battery system, the detection current of the first sampling node, and the detection current of the second sampling node to determine the current flowing through each battery pack 100, thereby realizing the monitoring of each battery pack 100.
[0061] Therefore, it is unnecessary to directly install a sampling device at the output terminal of the battery pack 100. The output current of the battery pack 100 is relatively large, ranging from 100A to 300A. The wiring of the battery pack is mostly thick wire or copper busbar, making sampling difficult. The sampling device needs to pass through the corresponding cables or copper busbars of the battery pack, which is expensive. This application sets a current sampling node in the energy regulation circuit 130, and the battery pack controller 140 can calculate the current flowing through each battery pack 100. The current of the energy regulation circuit 130 is usually small, so the implementation is relatively easy and the cost is very low, greatly reducing the system complexity and cost.
[0062] Reference Figure 8 , Figure 8 A sampling structure for a battery system is shown. For example... Figure 8 As shown, taking three battery packs (Pack, Pack2, and Pack3) of 100 as an example, i bat_s i is the total output of the battery system. bat For the output of each battery pack 100, i s i is the first sampling node. L This is the second sampling node. The battery pack controller 140 in each battery pack 100 can, according to i bat_sThe current at the location and the i in its own battery pack 100 s Current at position and i L The current at the location determines the battery pack i bat Current at location.
[0063] In this embodiment, the energy regulation circuit 130 within each battery pack is... Figure 4 Taking the structure shown as an example, the first switch K1 and the second switch K2 operate in high-frequency switching mode. (Refer to...) Figure 9 , Figure 9 The diagram illustrates a switch drive signal waveform and the current waveform of inductor L. The drive signal for the first switch K1 is G1, and the drive signal for the second switch K2 is G2. The duty cycle of drive signal G1 is D1, and the duty cycle of drive signal G2 is D2. Drive signals G1 and G2 can be complementary, i.e., D1 + D2 = 1. Alternatively, there can be a dead time between drive signals G1 and G2, meaning that for a certain period, both drive signals G1 and G2 are simultaneously low, and D1 + D2 ≤ 1.
[0064] As an example, D1 + D2 = 1. During the energy balancing process, from time t1 to time t2, the drive signal G1 is at a high level, the first switch K1 is turned on, the battery cell 120 charges the inductor L, and the current of the inductor L increases; from time t2 to time t3, the drive signal G2 is at a high level, the second switch K2 is turned on, the inductor L discharges outward, and the current of the inductor L decreases.
[0065] For a battery pack 100, there are two states during the energy balancing process: energy input and energy output. These two states can be synchronized or alternate. Taking Pack 2 as an example, during the energy balancing process, Pack 1 supplies energy to Pack 2, and Pack 2 can also supply energy to Pack 3. The two states are explained below.
[0066] Reference Figure 10A and Figure 10B , Figure 10A and Figure 10B The process of transferring energy from Pack2 to Pack3, in which Figure 10A correspond Figure 9 From time t1 to time t2, Figure 10B correspond Figure 9 From time t2 to t3. As shown in Figure 10, from time t1 to t2, i in Pack2 s Current at position and i L The current at each location is the same, and it flows through battery pack 100. bat Current at position and i s Current at position and i LThe current at each location is the same. As shown in Figure 11, the current in Pack2 is the same. s Current at position and i L The current at each location is the same, but the current i in Pack2 caused by this energy transfer path is different. bat It is zero.
[0067] Take I S_b This indicates that the equalization circuit in Pack2 causes i in Pack2 to... s The average current at the location, in I L_b This indicates that the equalization circuit in Pack2 causes i in Pack2 to... L The average current at the location, in I bat_b This indicates that the equalization circuit in Pack2 causes i in Pack2 to... bat The average current at the location. Due to the current i s and current i L They are the same, therefore they have the following relationship: I bat_b =I S_b *D1=I S_b * (1-D2) = I S_b -I L_b D2 Reference Figure 11A and Figure 11B , Figure 11A and Figure 11B The process of transferring energy from Pack1 to Pack2, in which Figure 11A correspond Figure 9 From time t1 to time t2 (and) Figure 10A The corresponding time intervals from t1 to t2 can be synchronized or not synchronized. Figure 11B correspond Figure 9 From time t2 to time t3 (and) Figure 10B (The corresponding time intervals from t2 to t3 can be synchronized or desynchronized). During the energy equalization process, from t1 to t2, i in Pack2... s Position and i L There is no current at any location. From time t2 to time t3, the current in Pack2 is... s The position has current and i L There is no current at this location.
[0068] Take I bat_a This indicates that the equalization circuit in Pack1 causes i in Pack2 to... bat The average current at the location, in I S_a This indicates that the equalization circuit in Pack1 causes i in Pack2 s The average current at a given location, therefore, has the following relationship: I bat_a =IS_a Take I bat_S For battery system i bat_s The current at the location. Due to the superposition principle, the combined effect of the energy regulation circuits 130 in Pack1 and Pack2 flows through the current in Pack2. bat Total current I at position bat The following relationship must be satisfied: I bat =I bat_S +I bat_a +I bat_b =I bat_S +I S_a +(I S_b -I L_b D2)=I bat_S +I S -I L_b D2 Among them, I S Represents any time i s The average current at the location. Because the energy regulation circuit 130 in Pack1 is operating, the current in Pack2 is not... L The position generates current, therefore at any time i L Average current I at location L =I L_b .
[0069] In summary, Pack2's i bat Total current I at position bat = I bat_S +I S -I L D2. Therefore, the battery pack controller 140 in Pack2 detects the internal i s Position and i L The average current at the location, combined with the duty cycle D2, can determine the total current flowing through its own battery cell 120.
[0070] It should be noted that, Figure 10A and Figure 10B The path shown can also be used to transfer energy from Pack3 to Pack2. Figure 11A and Figure 11B The path shown can also be used to transfer energy from Pack2 to Pack1. The only difference is the current path during the energy transfer process.
[0071] As an example, Pack1 and Pack3 can simultaneously supply energy to Pack2. Alternatively, Pack2 can simultaneously supply energy to Pack1 and Pack3. The direction of energy transfer between the packs can be set as needed, and this implementation does not impose any restrictions on this.
[0072] In some embodiments, the battery pack 100 has a control signal terminal COM on its housing 110. The battery pack 100 also includes a battery pack controller 140, which is connected to the battery unit 120, the energy regulation circuit 130 and the control signal terminal COM respectively. The battery system also includes a main control unit 150, which is electrically connected to the control signal terminal COM and configured to communicate with the battery pack controller 140.
[0073] The battery pack controller 140 is mainly used to detect the parameter information of each battery cell 120. The parameter information includes, but is not limited to, state of charge, voltage, current and temperature. The battery pack controller 140 transmits the detected information to the main control unit 150. The main control unit 150 can send control commands to the battery pack controller 140 according to the parameter information of each battery cell 120. The battery pack controller 140 controls the energy regulation circuit 130 to realize the energy transfer between each battery pack 100.
[0074] Reference Figure 12 , Figure 12 A flowchart of an energy regulation method provided by an embodiment of this application is shown. One embodiment of this application proposes an energy regulation method applied to the aforementioned battery system, which includes a first battery pack 100 and a second battery pack 100. The negative terminal P2 of the first battery pack 100 is connected to the positive terminal P1 of the second battery pack 100, and the energy transmission terminal Q of the first battery pack 100 is connected to the energy transmission terminal Q of the second battery pack 100. The energy regulation method includes steps 10 and 20.
[0075] Step 10: Obtain energy from the first and second battery cells; Step 20: Based on the energy of the first battery unit and the second battery unit, the energy regulation circuit 130 performs energy transfer between the first battery pack 100 and the second battery pack 100.
[0076] The energy regulation method provided in the embodiments of this application can be executed by the aforementioned main control unit 150 or a functional module or functional entity in the main control unit 150 that can implement the control method. The energy regulation method provided in the embodiments of this application will be described below with the main control unit 150 as the execution subject as an example.
[0077] After acquiring energy from the first battery unit and the second battery unit, the main control unit 150 can transfer energy from the higher-energy battery unit 120 to the lower-energy battery unit 120, or transfer the target energy from the first battery unit to the second battery unit as needed.
[0078] As an example, the initial energy of the first battery cell is E1, the initial energy of the second battery cell is E2, and the target energy is E0. The main control unit 150 can control the energy regulation circuit 130 in the first battery pack 100 to transfer the energy of E0 to the second battery cell until the energy of the first battery cell decreases from E1 to E1-E0, and the energy of the second battery cell increases from E2 to E2+E0.
[0079] Reference Figure 13 , Figure 13 A flowchart of an energy regulation method provided by an embodiment of this application is shown. The energy regulation method in the foregoing example is also applicable when multiple battery packs 100 are connected. For example, the initial energy of battery pack 100X is Ex, the initial energy of battery pack 100Y is Ey, and n battery packs 100 are connected between battery pack 100Y and battery pack 100X, where n is a natural number greater than 1. The main control unit 150 can control the operation of the energy regulation circuit 130 in the battery pack 100X and the battery pack 100 connected between the battery pack 100Y and the battery pack 100X. The target energy Ea in the battery pack 100X is transferred to the battery cell 120 connected between the battery pack 100Y and the battery pack 100X and connected to the battery pack 100X. The battery pack 100 connected between the battery pack 100Y and the battery pack 100X will transfer the target energy Ea to the battery pack 100Y in sequence until the energy of the battery cell 120 in the battery pack 100Y increases from Ey to Ey+Ea, and the energy of the battery cell 120 in the battery pack 100X decreases from Ex to Ex-Ea.
[0080] According to the energy regulation method of this application, the energy regulation circuit 130 is disposed inside the housing 110 of the battery pack 100, and can be connected to the energy regulation circuit 130 in other battery packs 100 through the connection terminals on the housing 110 to realize energy transfer between multiple battery cells 120. The terminals on the battery pack housing 110 facilitate the detachable connection of multiple battery packs 100, thereby improving the modular expansion capability of the battery pack 100.
[0081] Reference Figure 14 , Figure 14A flowchart of an energy regulation method provided by an embodiment of this application is shown. In some embodiments, the energy regulation circuit 130 is controlled to transfer energy between the first battery pack 100 and the second battery pack 100 based on the energy of the first battery cell and the second battery cell, including: when the first energy of the first battery cell is less than the second energy of the second battery cell, and the absolute value of the difference between the first energy and the second energy is greater than a preset threshold, controlling the second energy regulation circuit 130 to transfer the target energy in the second battery cell to the first energy regulation circuit 130, and controlling the first energy regulation circuit 130 to transfer the target energy to the first battery cell; when the first energy of the first battery cell is greater than the second energy of the second battery cell, and the absolute value of the difference between the first energy and the second energy is greater than a preset threshold, controlling the first energy regulation circuit 130 to transfer the energy in the first battery cell to the second energy regulation circuit 130, and controlling the second energy regulation circuit 130 to transfer the target energy to the second battery cell.
[0082] If the absolute value of the difference between the first energy and the second energy is greater than a preset threshold, it indicates an energy imbalance between the first and second battery cells. The energy in battery cell 120 is typically calculated based on directly measurable parameters such as voltage; therefore, comparing the energy of battery cell 120 can be converted into comparing its voltage. The specific value of the preset threshold can be selected based on the actual application scenario and is not limited here. For example, the preset threshold could be 0.2V or 0.5V, etc.
[0083] When the energy of the first battery cell is less than the energy of the second battery cell, and the absolute value of the energy difference between the two exceeds a preset threshold, the second energy regulation circuit 130 is controlled to transfer the target energy in the second battery cell to the first energy regulation circuit 130, so that the energy of the second battery cell decreases. The first energy regulation circuit 130 is then controlled to transfer the target energy to the first battery cell, so that the energy of the first battery cell increases, until the absolute value of the difference between the first energy and the second energy is less than or equal to the equilibrium threshold, and the equilibrium threshold is less than the preset threshold, that is, until the energy in the first battery cell and the second battery cell reaches equilibrium.
[0084] When the energy of the first battery cell is greater than the energy of the second battery cell, and the absolute value of the energy difference between the two exceeds a preset threshold, the first energy regulation circuit 130 is controlled to transfer the target energy in the first battery cell to the second energy regulation circuit 130, so that the energy of the first battery cell decreases. The second energy regulation circuit 130 is then controlled to transfer the target energy to the second battery cell, so that the energy of the second battery cell increases, until the absolute value of the difference between the first energy and the second energy is less than or equal to the preset threshold, and the equilibrium threshold is less than the preset threshold, that is, until the energy in the first battery cell and the second battery cell reaches equilibrium.
[0085] Reference Figure 15 , Figure 15 A process for current detection during balancing is illustrated. In some embodiments, the battery packs 100 in the battery system are connected in series, and the energy regulation circuit 130 includes a first balancing line and a second balancing line. The first balancing line is used to connect the battery cells in the next battery pack, and the second balancing line is used to connect the battery cells in the previous battery pack. The energy regulation method further includes steps 30, 40, and 50.
[0086] Step 30: Obtain the total current of the battery system; Step 40: During the energy transfer process, determine the first average current on the first equalization line and the second average current on the second equalization line. Step 50: The total current, the first average current, and the second average current are superimposed to obtain the actual current flowing through the battery cells in the battery pack.
[0087] It is understandable that during the operation of the battery system, if there is no energy balance, the total current of the battery system is the current flowing through each battery pack 100. If there is energy balance, the current flowing through each battery pack 100 is the total current of the battery system plus the current of the battery pack 100 caused by the energy balance process.
[0088] In this embodiment, the battery packs 100 are connected in series, and each battery pack 100 can transfer energy with two adjacent battery packs 100. In this embodiment, the energy regulation circuit 130 includes a first equalization line and a second equalization line. The first equalization line is used to realize energy transfer between its own battery pack and the next battery pack, and the second equalization line is used to realize energy transfer between its own battery pack and the previous battery pack. The first equalization line and the second equalization line can work independently or simultaneously.
[0089] Reference Figure 10A , Figure 10B , Figure 11A and Figure 11B If pack2 is used as its own battery pack, then the previous battery pack can refer to pack1, and the next battery pack can refer to pack3; of course, the previous battery pack can refer to pack3, and the next battery pack can refer to pack1.
[0090] Sampling nodes can be set on the first and second equalization lines to detect the first and second average currents, respectively. During the energy equalization process, the current flowing through the battery pack 100 can be obtained by superimposing the total current, the first average current, and the second average current. This enables the monitoring of each battery pack 100. Furthermore, since the current in the energy regulation circuit 130 is typically small, the implementation is relatively easy and the cost is very low, significantly reducing the system's complexity and cost.
[0091] As an example, refer to Figure 10A , Figure 10B , Figure 11A and Figure 11B The first equalization circuit includes an energy storage element, a first switch K1, and a second switch K2. The first terminal of the energy storage element is connected to the first terminal of both the first switch K1 and the second switch K2. The second terminal of the first switch K1 is connected to the positive terminal of the battery cell, and the second terminal of the energy storage element is connected to the negative terminal of the battery cell. The second terminal of the second switch K2 is used to connect to a battery cell in the next battery pack. Determining the first average current on the first equalization circuit includes: Determine the third average current of the first line between the second terminal of the energy storage element and the negative terminal of the battery cell; The first average current is determined according to the following formula: I bat_b =I S_b *D1=I S_b *(1-D2) Among them, I bat_b I is the first average current. S_b Let D1 be the third average current, D2 be the duty cycle of the drive signal for the first switch, and D2 be the duty cycle of the drive signal for the second switch, with D1 + D2 ≤ 1. The energy storage element can be an inductor L. The first end of the inductor L is connected to the first end of the first switch K1 and the first end of the second switch K2, respectively, and the second end of the inductor L is connected to the negative terminal of the battery cell. The working principle of the first equalization circuit can be referred to the aforementioned embodiments, and will not be repeated here.
[0092] The sampling position of the third average current can be i s Position and i L Position, during the operation of the first equalization circuit, i s Current at position and i L The current is the same at each location. (Combined) Figure 9 The period from time t1 to time t3 represents an energy balance cycle. Between time t1 and time t2, the first switch K1 is closed and the second switch K2 is open; between time t2 and time t3, the first switch K1 is open and the second switch K2 is closed.
[0093] Combination Figure 10A and Figure 10B , with I S_b This indicates that the equalization circuit in Pack2 causes i in Pack2 to... s The average current at the location, in I L_b This indicates that the equalization circuit in Pack2 causes i in Pack2 to... L The average current at the location, in I bat_b This indicates that the equalization circuit in Pack2 causes i in Pack2 to... bat The average current at the location. Due to the current i s and current i L They are the same, therefore they have the following relationship: I bat_b =I S_b *D1=I S_b * (1-D2) = I S_b -I L_b D2 Among them, I bat_b This represents the first average current.
[0094] In some embodiments, the first end of the second balancing line is connected to the first line, and the first line includes a second line connected between the negative electrode of the battery cell and the first end of the second balancing line, and a third line connected between the first end of the second balancing line and the second end of the energy storage element.
[0095] In this embodiment, the sampling position of the second line is i. s Location, the sampling position of the third line is i L Position. The second average current of the second equalization line can be obtained by adjusting i. s Location sampling determined. Combined with... Figure 9 The time interval from t1 to t3 represents one energy balance cycle. In this embodiment, the energy balance cycle of the second balance line can be synchronized with or different from the energy balance cycle of the first balance line.
[0096] Combination Figure 11A and Figure 11B During the energy equilibrium process, from time t1 to time t2, the i in Pack2 s Position and i L There is no current at any location. From time t2 to time t3, the current in Pack2 is... s The position has current and i L There is no current at this location. (Using I) bat_a This indicates that the equalization circuit in Pack1 causes i in Pack2 bat The average current at the location, in I S_a This indicates that the equalization circuit in Pack1 causes i in Pack2 sThe average current at a given location, therefore, has the following relationship: I bat_a =I S_a Among them, I bat_a This represents the second average current.
[0097] Therefore, the actual current is determined according to the following formula: I bat =I bat_S +I S -I L *D2 Among them, I bat For the actual current, I bat_S For the total current, I S I is the average current of the second line. L This represents the average current of the third line.
[0098] Therefore, the battery pack controller 140 inside each battery pack 100 can obtain i by executing the above process. s Position and i L The average current at the location, combined with the duty cycle D2, can determine the total current flowing through its own battery cell 120, thus enabling monitoring of the current flowing through its own battery pack 100.
[0099] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.
[0100] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A battery system, characterized in that, Includes multiple battery packs, the battery packs comprising: A housing having a positive terminal, a negative terminal, and at least one power transmission terminal; A battery cell is disposed within the housing, with the positive terminal of the battery cell connected to the positive terminal and the negative terminal of the battery cell connected to the negative terminal. An energy regulation circuit is disposed within the housing. The energy regulation circuit is connected to the energy transmission terminal and the battery cell. The energy regulation circuit is configured to transmit energy input from the energy transmission terminal to the battery cell and to output energy from the battery cell from the energy transmission terminal. The battery packs are interconnected via the positive terminal, the negative terminal, and the energy transmission terminal.
2. The battery system according to claim 1, characterized in that, The energy regulation circuit includes: An energy storage element, wherein a first end of the energy storage element is connected to a first electrode of the battery cell; A switching circuit is connected to the second terminal of the battery cell, the second terminal of the energy storage element, and the energy transmission terminal, respectively. The switching circuit is configured to conduct the energy transmission path between the second terminal of the battery cell and the second terminal of the energy storage element, or to conduct the energy transmission path between the second terminal of the energy storage element and the energy transmission terminal. A transmission line, wherein a first end of the transmission line is connected to a first end of the energy storage element, and a second end of the transmission line is connected to the energy transmission terminal.
3. The battery system according to claim 2, characterized in that, The energy storage element is an inductor, and the first terminal of the inductor is connected to the first terminal of the battery cell. The switching circuit includes: A first switch, wherein a first end of the first switch is connected to the second terminal of the battery cell, and a second end of the first switch is connected to the second end of the inductor; The second switch has its first end connected to the second end of the first switch and the second end of the inductor, and its second end connected to the energy transmission terminal.
4. The battery system according to claim 3, characterized in that, The energy transmission terminal includes a first energy transmission terminal and a second energy transmission terminal. The first energy terminal is connected to the second end of the transmission line, and the second energy transmission terminal is connected to the second end of the second switch.
5. The battery system according to claim 4, characterized in that, The transmission line is directly connected between the first energy terminal and the first pole of the battery cell.
6. The battery system according to claim 3, characterized in that, The housing is also provided with control signal terminals, and the battery pack further includes: A battery pack controller is electrically connected to the control signal terminal, the drive terminal of the first switch, and the drive terminal of the second switch, respectively, and is configured to drive the first switch with a first pulse signal and drive the second switch with a second pulse signal, wherein the duty cycle of the first pulse signal and the duty cycle of the second pulse signal are complementary.
7. The battery system according to claim 2, characterized in that, The first end of the transmission line is disposed between the first terminal of the battery cell and the first end of the energy storage element, and the battery pack further includes: The current detection circuit has a first sampling node and a second sampling node. The first sampling node is disposed between the first pole of the battery cell and the first end of the transmission line, and the second sampling node is disposed between the first end of the transmission line and the first end of the energy storage element. The current detection circuit is configured to determine the current flowing through the battery pack based on the sampled current of the first sampling node and / or the second sampling node.
8. The battery system according to any one of claims 1-7, characterized in that, The battery pack housing is provided with control signal terminals, and the battery pack also includes a battery pack controller, which is connected to the battery cells, the energy regulation circuit and the control signal terminals respectively. The battery system further includes a main control unit, which is electrically connected to the control signal terminals of each of the battery packs and configured to communicate with the battery pack controller.
9. An energy regulation method, characterized in that, The battery system according to any one of claims 1-7, the battery system comprising a first battery pack and a second battery pack, wherein the negative terminal of the first battery pack is connected to the positive terminal of the second battery pack, and the energy transmission terminal of the first battery pack is connected to the energy transmission terminal of the second battery pack, the energy regulation method comprising: Obtain energy from the first and second battery cells; The energy control and energy regulation circuit, based on the energy of the first battery cell and the second battery cell, performs energy transfer between the first battery pack and the second battery pack.
10. The energy regulation method according to claim 9, characterized in that, The energy regulation circuit that controls the energy of the first battery cell and the second battery cell to transfer energy between the first battery pack and the second battery pack includes: When the first energy of the first battery cell is less than the second energy of the second battery cell, and the absolute value of the difference between the first energy and the second energy is greater than a preset threshold, the second energy regulation circuit is controlled to transfer the target energy in the second battery cell to the first energy regulation circuit, and the first energy regulation circuit is controlled to transfer the target energy to the first battery cell. When the first energy of the first battery cell is greater than the second energy of the second battery cell, and the absolute value of the difference between the first energy and the second energy is greater than the preset threshold, the first energy regulation circuit is controlled to transfer the energy in the first battery cell to the second energy regulation circuit, and the second energy regulation circuit is controlled to transfer the target energy to the second battery cell.
11. The energy regulation method according to claim 9 or 10, characterized in that, The battery packs in the battery system are connected in series. The energy regulation circuit includes a first balancing line and a second balancing line. The first balancing line is used to connect to the battery cells in the next battery pack, and the second balancing line is used to connect to the battery cells in the previous battery pack. The energy regulation method further includes: Obtain the total current of the battery system; During the energy transfer process, a first average current on the first equalization line and a second average current on the second equalization line are determined. The actual current flowing through the battery cells in its own battery pack is obtained by superimposing the total current, the first average current, and the second average current.
12. The energy regulation method according to claim 11, characterized in that, The first equalization circuit includes an energy storage element, a first switch, and a second switch. The first end of the energy storage element is connected to the first end of the first switch and the first end of the second switch, respectively. The second end of the first switch is connected to the positive terminal of the battery cell, and the second end of the energy storage element is connected to the negative terminal of the battery cell. The second end of the second switch is used to connect to the battery cell in the next battery pack. Determining the first average current on the first equalization line includes: Determine the third average current of the first line between the second terminal of the energy storage element and the negative terminal of the battery cell; The first average current is determined according to the following formula: I bat_b =I S_b *D1=I S_b *(1-D2) Among them, I bat_b Let I be the first average current. S_b The third average current is given, D1 is the duty cycle of the drive signal of the first switch, D2 is the duty cycle of the drive signal of the second switch, and D1+D2≤1.
13. The energy regulation method according to claim 12, characterized in that, The first end of the second balancing circuit is connected to the first circuit. The first circuit includes a second circuit connected between the negative terminal of the battery cell and the first end of the second balancing circuit, and a third circuit connected between the first end of the second balancing circuit and the second end of the energy storage element. The actual current is determined according to the following formula: I bat =I bat_S +I S -I L *D2 Among them, I bat For the actual current, I bat_S For the total current, I S I is the average current of the second line. L The average current of the third line is given.