Control circuit of battery pack and vehicle

Abstract

The invention provides a control circuit of a battery pack and a vehicle, and the control circuit comprises a plurality of first circuits, each first circuit comprises at least one wiring unit and at least one first switch, and the wiring unit is used for being connected with at least one battery monomer; the active equalization circuit unit is provided with a plurality of branches, the first end of each branch is connected with the first circuit through a switch assembly, and the second end of each branch is connected with the equalization power supply; the control unit is connected with the first switches in the first circuits and the active equalization circuit units, and is used for controlling the on-off of the first switches and the active equalization circuit units, so that closed second circuits are formed between the at least two branches and the at least two battery monomers and between the at least two branches and the equalization power supply respectively; therefore, the charging and discharging states of the single batteries and the balanced power supply are regulated. Through cooperation of the active equalization circuit and the passive equalization circuit, the number of components on the active equalization circuit is reduced, and the cost of the active equalization circuit is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery packs, and in particular to a control circuit of a battery pack and a vehicle. Background Art

[0002] In new energy vehicles and large-scale energy storage systems, battery packs consist of multiple battery cells connected in series or parallel. Due to manufacturing variations and varying degrees of aging, the state of charge (SOC) and voltage of each battery cell can become uneven. This not only affects the battery's total capacity and power output, but also accelerates the degradation of the weakest cell, thereby reducing the overall efficiency and safety of the battery pack. Cell balancing aims to control the flow of energy between battery cells, maintaining approximately the same SOC and voltage across all cells, thereby maximizing the overall performance of the battery pack and extending its lifecycle.

[0003] Currently, battery balancing solutions are mainly divided into two categories: passive balancing solutions and active balancing solutions. The passive balancing solution is to discharge the high-voltage battery cells by connecting resistors in parallel. The energy is dissipated in the form of heat, and the balancing efficiency is low, which makes it difficult to meet the growing high-power operation demand of the new energy industry. The active balancing solution achieves a more efficient balancing effect through energy recycling, but due to its complex circuit design and the need for high-voltage and high-precision components, the cost increases significantly, which poses a major challenge to commercial applications that pursue cost-effectiveness.

[0004] With respect to the technical problem of high cost of active equalization solutions in the prior art, no effective solution has been proposed yet. Summary of the Invention

[0005] The main purpose of the present invention is to provide a control circuit for a battery pack and a vehicle to solve the technical problem of high cost of active balancing solutions in the prior art.

[0006] To achieve the above objectives, according to one aspect of the present invention, a control circuit for a battery pack is provided, comprising: a first circuit, wherein the first circuits are multiple, each of the first circuits includes at least one wiring unit and at least one first switch, the wiring unit being configured to be connected to at least one battery cell; an active balancing circuit unit, wherein the active balancing circuit unit is provided with multiple branches, wherein a first end of each branch is connected to the first circuit via a switch assembly, and a second end of each branch is connected to a balancing power supply; and a control unit, wherein the control unit is connected to the first switch and the active balancing circuit unit in each first circuit, and the control unit is configured to control the on and off of the first switch and the active balancing circuit unit, so that a closed second circuit is formed between at least two branches, respectively, and the at least two battery cells and the balancing power supply, thereby regulating the charge and discharge states of each battery cell and the balancing power supply.

[0007] Furthermore, the switch assembly includes a first switch assembly, which includes: a second switch, wherein a first pin of the second switch is connected to a high potential point of the first circuit, and a second pin of the second switch is connected to a low potential point of the first circuit; a third switch, wherein a fourth pin of the third switch is connected to an electrode of one of the battery cells, a fifth pin of the third switch is connected to an electrode of the balancing power supply, and a sixth pin of the third switch is connected to the third pin of the second switch. When at least one of the first circuits forms a closed loop, the second switch and the third switch corresponding to the closed loop are automatically turned on, so that a charge and discharge circuit is formed between the branch where the second switch and the third switch are located and the at least one battery cell and the balancing power supply.

[0008] Furthermore, the second switch and the third switch are both MOS transistors.

[0009] Furthermore, the switch assembly also includes a second switch assembly, which includes a first double-pole relay and a second double-pole relay, and the second end of each branch is provided with a first branch and a second branch, the first branch is connected to the electrode of the balanced power supply through the first double-pole relay, and the second branch is connected to the electrode of the balanced power supply through the second double-pole relay.

[0010] Furthermore, each first circuit has two first resistors connected in series, and each first resistor is arranged in parallel with a diode, wherein the current flow direction of one diode is the same as the current flow direction of the first circuit, and the current flow direction of the other diode is opposite to the current flow direction of the first circuit.

[0011] Furthermore, each branch of the active balancing circuit unit is connected in series with a second resistor.

[0012] Furthermore, the control unit includes: an analog front-end chip, which is connected to the battery cell and the first switch, and is used to collect the voltage signal of each battery cell, and control the on and off of the first switch according to the voltage signal; a control chip, which is signal-connected to the analog front-end chip, and is used to regulate the voltage of the equalizing power supply according to the voltage signal, and control the on and off of the second switch component according to the voltage signal.

[0013] Furthermore, the control chip includes: a main control chip, which is connected to the analog front-end chip signal, and the main control chip is used to regulate the voltage of the balanced power supply according to the voltage signal; a sub-control chip, which is connected to the analog front-end chip signal, and the sub-control chip is used to regulate the on and off of the second switch component according to the voltage signal.

[0014] Furthermore, the control circuit further includes: an isolated power supply, and each chip in the control unit is respectively connected to the isolated power supply.

[0015] According to another aspect of the present invention, a vehicle is provided. The vehicle includes a battery pack, and the control circuit of the battery pack is the above-mentioned control circuit.

[0016] Using the technical solution of the present invention, the first circuit is connected to the battery cells via a wiring unit, forming a passive balancing circuit. The branches in the active balancing circuit unit are connected between the first circuit and the balancing power supply, forming a charge-discharge circuit between the battery cells and the balancing power supply. This design reduces the direct impact of high voltage on the active balancing circuit. The control unit controls the charge and discharge states of the battery cells and the balancing power supply by turning the first switch and the active balancing circuit unit on and off, thereby achieving energy circulation between the battery cells and the balancing power supply. In this solution, the active balancing circuit is combined with the existing passive balancing circuit to reduce the number of components in the active balancing circuit, lowering the need for high-voltage, high-precision components and significantly reducing the cost of the active balancing circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 A schematic structural diagram of a first embodiment of a control circuit according to the present invention is shown;

[0019] Figure 2 FIG. 1 is a schematic structural diagram of a second embodiment of a control circuit according to the present invention.

[0020] The above drawings include the following reference numerals:

[0021] 10. Battery cells;

[0022] 20. First circuit;

[0023] 21. First switch; 22. First resistor; 23. Diode;

[0024] 30. Active balancing circuit unit;

[0025] 310, branch; 311, second switch; 3111, first pin; 3112, second pin; 3113, third pin; 312, third switch; 3121, fourth pin; 3122, fifth pin; 3123, sixth pin; 313, second resistor; 314, first double-pole relay; 315, second double-pole relay;

[0026] 40. Balanced power supply;

[0027] 50. Control unit;

[0028] 510, analog front-end chip; 520, main control chip; 530, auxiliary control chip. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of this application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0033] Combine Figures 1 to 2 As shown, according to a specific embodiment of the present application, a control circuit of a battery pack is provided.

[0034] Specifically, the battery pack control circuit includes: a first circuit 20, an active balancing circuit unit 30, and a control unit 50. There are multiple first circuits 20, each of which includes at least one wiring unit and at least one first switch 21. The wiring unit is used to connect to at least one battery cell 10. The active balancing circuit unit 30 has multiple branches 310. The first end of each branch 310 is connected to the first circuit 20 via a switch assembly, and the second end of each branch 310 is connected to the balancing power supply 40. The control unit 50 is connected to the first switch 21 and the active balancing circuit unit 30 in each first circuit 20. The control unit 50 is used to control the opening and closing of the first switch 21 and the active balancing circuit unit 30, so that at least two branches 310 form a closed second circuit with at least two battery cells 10 and the balancing power supply 40, respectively, to regulate the charge and discharge status of each battery cell 10 and the balancing power supply 40.

[0035] In an embodiment of the present application, the first circuit 20 is connected to the battery cells 10 via a wiring unit to form a passive balancing circuit. Each branch 310 in the active balancing circuit unit 30 is connected between the first circuit 20 and the balancing power supply 40, forming a charge-discharge circuit between the battery cells 10 and the balancing power supply 40. This design reduces the direct impact of high voltage on the active balancing circuit. The control unit 50 controls the charge and discharge states of the battery cells 10 and the balancing power supply 40 by switching the first switch 21 and the active balancing circuit unit 30 on and off, thereby achieving energy circulation between the battery cells 10 and the balancing power supply 40. In this solution, the active balancing circuit is combined with the existing passive balancing circuit to reduce the number of components in the active balancing circuit, lowering the need for high-voltage, high-precision components, and significantly reducing the cost of the active balancing circuit.

[0036] It is understood that the wiring units on the first circuit 20 refer to the wiring pins at both ends of the first circuit 20. The first circuit 20 is connected to the battery cell 10 through the wiring pins at both ends to form a passive balancing circuit. When the first switch 21 connected in series with the passive balancing circuit is closed, the battery cell 10 will dissipate excess energy as heat through the passive balancing circuit, thereby reducing the voltage of the battery cell 10.

[0037] It should be noted that each branch 310 of the active balancing circuit unit 30 is connected between the first circuit 20 and the balancing power supply 40, so that the battery cells 10 are connected to the balancing power supply 40 through the branches 310. That is, each branch 310 plays a voltage conduction role, allowing energy circulation between the battery cells 10 and the balancing power supply 40.

[0038] In an exemplary embodiment of the present application, the switch assembly includes a first switch assembly 21, which includes a second switch 311 and a third switch 312. A first pin 3111 of the second switch 311 is connected to a high potential point of the first circuit 20, and a second pin 3112 of the second switch 311 is connected to a low potential point of the first circuit 20. A fourth pin 3121 of the third switch 312 is connected to an electrode of one of the battery cells 10, a fifth pin 3122 of the third switch 312 is connected to an electrode of the balancing power supply 40, and a sixth pin 3123 of the third switch 312 is connected to the third pin 3113 of the second switch 311. When at least one first circuit 20 forms a closed loop, the second switch 311 and the third switch 312 corresponding to the closed loop are automatically turned on, thereby forming a charge-discharge circuit between the portion of the branch 310 where the second switch 311 and the third switch 312 are located, the at least one battery cell 10, and the balancing power supply 40.

[0039] In the embodiment of the present application, when a voltage imbalance is detected between battery cells 10, at least one first circuit 20 corresponding to the unbalanced battery cell 10 automatically forms a closed loop. The second switch 311 and the third switch 312 corresponding to the loop are automatically turned on, establishing a direct charge and discharge path from the battery cell 10 to the balancing power supply 40, thereby achieving fast and automatic balancing adjustment without the need for continuous external interference or complex algorithm instructions.

[0040] Preferably, the second switch 311 and the third switch 312 are both MOS transistors. Compared to traditional relays or other types of switches, MOS transistors have significant advantages in response speed and control accuracy. For battery packs of different sizes and types, only the parameters of the MOS transistors need to be adjusted accordingly, without requiring large-scale changes to the entire circuit. This helps simplify the design of the battery pack control circuit, reduces the number and size of required components, and thus reduces system costs.

[0041] It can be understood that the core of the MOS transistor is a semiconductor channel region surrounded by an insulating layer. This semiconductor channel is located between the source and the drain, and the gate is located above the insulating layer. The voltage difference between the gate and the source determines the conductivity of the channel region, thereby controlling the conduction state between the source and the drain.

[0042] like Figure 1As shown, each branch 310 of the active balancing circuit unit 30 is equipped with a second switch 311 and a third switch 312, wherein both the second switch 311 and the third switch 312 are MOS transistors. The second switch 311 is located near the first circuit 20 and is a P-MOS transistor. The gate pin of the second switch 311 is connected to a low potential point on the first circuit 20, the source pin of the second switch 311 is connected to a high potential point on the first circuit 20, and the drain pin of the second switch 311 is connected to the gate pin of the third switch 312. The third switch 312 is located near the balancing power supply 40 and is an N-MOS transistor. The source of the third switch 312 is connected to an electrode of the battery cell 10. The source potential of the third switch 312 is lower than the gate potential of the third switch 312, and the drain pin of the third switch 312 is connected to an electrode of the balancing power supply 40.

[0043] like Figure 1 As shown, when the first circuit 20 is closed, the source and drain of the corresponding second switch 311 are turned on, and the voltage of the high potential point on the first circuit 20 is sequentially directed to the drain of the second switch 311 and the gate of the third switch 312. At this time, the source and drain of the corresponding third switch 312 are turned on, connecting the electrodes of the battery cell 10 to the electrodes of the balancing power supply 40, thereby forming a charge-discharge circuit between the battery cell 10 and the balancing power supply 40.

[0044] It is understood that when the gate voltage of the P-MOS transistor is lower than the source voltage and reaches the turn-on voltage, the P-MOS transistor begins to conduct. When the gate voltage of the N-MOS transistor is higher than the source voltage and greater than the turn-on voltage, the N-MOS transistor begins to conduct.

[0045] In an exemplary embodiment of the present application, the switch assembly also includes a second switch 311 assembly, the second switch 311 assembly includes a first double-pole relay 314 and a second double-pole relay 315, and the second end of each branch 310 is provided with a first branch and a second branch, the first branch is connected to the electrode of the balancing power supply 40 through the first double-pole relay 314, and the second branch is connected to the electrode of the balancing power supply 40 through the second double-pole relay 315.

[0046] In the embodiments of the present application, a double-pole relay is provided to achieve two different path selections. This allows for flexible control of the energy flow based on the charge / discharge state and SOC differences of the battery cells. Energy can flow from the battery cells 10 to the balancing power supply 40, and vice versa, ensuring efficient energy circulation during the balancing process. Furthermore, the use of a double-pole relay can simplify the design of the balancing circuit. Specifically, the double-pole relay, in conjunction with the first switch 21 component, selectively charges and discharges each battery cell 10, reducing circuit costs.

[0047] The double-pole relay, a mechanical switch, provides high-voltage isolation, ensuring electrical isolation between the battery cells 10 and the balancing power supply 40, as well as between the battery cells 10 and the control circuit. This isolation mechanism is particularly important during the battery balancing process, preventing high-voltage circuits from interfering with low-voltage circuits. It also reduces the overall leakage and electric shock risks of the battery management system, significantly improving system safety and stability.

[0048] like Figure 1 As shown, the first double-pole relay 314 has a first contact mechanism and a second contact mechanism. The first contact mechanism is connected to the positive electrode of the balancing power supply 40, and the second contact mechanism is connected to the negative electrode of the balancing power supply 40. The second double-pole relay 315 has a third contact mechanism and a fourth contact mechanism. The third contact mechanism is connected to the positive electrode of the balancing power supply 40, and the fourth contact mechanism is connected to the negative electrode of the balancing power supply 40. The second end of each branch 310 of the active balancing circuit unit 30 is provided with a first branch and a second branch. The first branch is connected to the first contact mechanism, and the second branch is connected to the fourth contact mechanism; alternatively, the first branch is connected to the second contact mechanism, and the second branch is connected to the third contact mechanism. The first branch and the second branch are both connected to the drain pin of the third switch 312.

[0049] like Figure 1 As shown, when the voltage of the battery cell 10B1 needs to be balanced, the control unit 50 controls the first switches 21S1, S2, S3 and S4 to be closed; at this time, the two branches 310 on the active balancing circuit unit 30 are turned on, wherein the gate potential of the second switch 311 on the first branch 310 is lower than V3, the source potential of the second switch 311 is V3, and the drain potential of the second switch 311 is V3, that is, the gate potential of the third switch 312 is V3, and the source potential of the third switch 312 is V0, then the double-pole relay connected to the first branch 310 is turned on. The potential of the relay is V0; the gate potential of the second switch 311 on the second branch 310 is lower than V4, the source potential of the second switch 311 is V4, and the drain potential of the second switch 311 is V4. That is, the gate potential of the third switch 312 is V4, and the source potential of the third switch 312 is V1. Then, the potential of the double-pole relay connected to the first branch 310 is V1. At this time, closing one of the first double-pole relay 314 and the second double-pole relay 315 can achieve conduction between the charge and discharge circuits of the battery cell 10B1 and the balancing power supply 40. Among them, the P-MOS transistor and the N-MOS transistor are responsible for fast response and precise control, and the double-pole relay provides stable and reliable energy path selection and high-voltage isolation. This combined design has significant cost-effectiveness advantages.

[0050] Preferably, the battery cells 10 can be numbered. For example, if battery cell 10 number n fails, the control unit 50 controls the first switches 21Sn+2 to Sn+3 to close, and controls the corresponding double-pole relays to close (for example, when the battery cell 10 is numbered odd, the first double-pole relay 314 is closed, and when the battery cell 10 is numbered even, the second double-pole relay 315 is closed).

[0051] In an exemplary embodiment of the present application, two first resistors 22 are connected in series on each first circuit 20, and each first resistor 22 is arranged in parallel with a diode 23, wherein the current flow direction of one diode 23 is the same as the current flow direction of the first circuit 20, and the current flow direction of the other diode 23 is opposite to the current flow direction of the first circuit 20.

[0052] In the embodiment of the present application, diode 23, which flows in the opposite direction to the current of first circuit 20, prevents reverse current from flowing, thereby avoiding circuit overload or battery damage. Diode 23, which flows in the same direction as the current of first circuit 20, increases the voltage difference across first resistor 22, ensuring conduction of the MOS transistor. Utilizing the natural conduction and cutoff characteristics of diode 23 to control energy flow reduces the need for complex control circuitry, simplifies communication logic, and reduces the complexity and cost of the overall circuit design.

[0053] like Figure 1 As shown, each first circuit 20 is connected in series with two first resistors 22, and two adjacent first circuits 20 share one first resistor 22. When the voltages of the battery cells 10B1 need to be balanced, the control unit 50 controls the first switches 21S3 and 21S4 to close. The diode 23 increases the voltage difference across the first resistor 22 near V4 and the voltage difference across the first resistor 22 near V3, thereby increasing the voltage difference between the gate and source of the corresponding second switch 311, allowing the corresponding second switch 311 and third switch 312 to conduct smoothly.

[0054] In an exemplary embodiment of the present application, each branch 310 of the active balancing circuit unit 30 is connected in series with a second resistor 313 .

[0055] In the embodiment of the present application, the second resistor 313 is provided to limit the current. When energy is transferred from high voltage to low voltage, the current is limited by the second resistor 313, thereby preventing excessive current from damaging the battery and circuit components.

[0056] like Figure 1 As shown, the second resistor 313 is disposed between the second switch 311 and the third switch 312 , and the resistance of the second resistor 313 can be set according to actual needs.

[0057] In one exemplary embodiment of the present application, the control unit 50 includes an analog front-end chip 510 and a control chip. The analog front-end chip 510 is connected to the battery cells 10 and the first switch 21. The analog front-end chip 510 is used to collect voltage signals from each battery cell 10 and control the on / off state of the first switch 21 based on the voltage signals. The control chip is signal-connected to the analog front-end chip 510 and is used to regulate the voltage of the balancing power supply 40 based on the voltage signals and control the on / off state of the second switch 311 based on the voltage signals.

[0058] Preferably, the control chip includes a main control chip 520 and a secondary control chip 530. The main control chip 520 is signal-connected to the analog front-end chip 510 and is configured to regulate the voltage of the balanced power supply 40 based on the voltage signal. The secondary control chip 530 is signal-connected to the analog front-end chip 510 and is configured to regulate the on / off state of the second switch 311 component based on the voltage signal.

[0059] In the embodiment of the present application, the main control chip 520 and the secondary control chip 530 work together to form a distributed control system, capable of fine-grained management of different aspects of cell balancing. The main control chip 520 focuses on regulating the voltage of the balancing power supply 40, ensuring that its output voltage meets the voltage accuracy requirements of the cell balancing process; while the secondary control chip 530 is dedicated to on-off control of the second switch 311 component, controlling the connection of the battery cells 10 to the balancing power supply 40. This distributed control approach improves the system's response speed and processing power, while also reducing the burden on the single control unit 50 and improving overall stability.

[0060] like Figure 2 As shown, the balancing power supply 40 is connected to a double-pole relay via an isolation transformer, and the double-pole relay is connected to each branch 310 on the active balancing circuit unit 30, thereby forming a charge and discharge circuit between the battery cell 10 and the balancing power supply 40, wherein the balancing power supply 40 is a 24V low-voltage power supply.

[0061] Specifically, the pins of the analog front-end chip 510 are connected to each battery cell 10 for real-time monitoring of the voltage of each battery cell 10. The analog front-end chip 510 can accurately collect the voltage signal of the battery cell 10 and convert the analog signal into a digital signal for subsequent processing and analysis. The main control chip 520 receives the voltage signal from the analog front-end chip 510 and regulates the voltage of the balancing power supply 40 based on the voltage signal to charge and discharge the battery cell 10 to be balanced. The secondary control chip 530 receives the voltage signal from the analog front-end chip 510 and controls the on and off of the double-pole relay based on the voltage signal, as well as the duration of the double-pole relay's connection.

[0062] In an exemplary embodiment of the present application, the control circuit further includes: an isolated power supply, and each chip in the control unit 50 is respectively connected to the isolated power supply.

[0063] In an embodiment of the present application, the isolated power supply isolates each chip in the control unit 50 from the main power supply or other high-voltage circuits through physical or magnetic induction isolation, effectively avoiding electrical interference between circuits of different voltage levels, reducing the risk of short circuit, leakage or electric shock, and significantly improving the safety of the system.

[0064] Furthermore, the isolated power supply is connected to the battery cell 10 with a higher voltage, so that the isolated power supply is connected to the gate of the third switch 312 as a high potential point to turn on the corresponding branch 310 in the active balancing circuit unit 30, so as to avoid the lower voltage difference from failing to turn on the corresponding branch 310.

[0065] According to another specific embodiment of the present application, a vehicle is provided. The vehicle includes a battery pack, and the control circuit of the battery pack is the control circuit in the above embodiment.

[0066] Specifically, the battery pack control circuit includes: a first circuit 20, an active balancing circuit unit 30, and a control unit 50. There are multiple first circuits 20, each of which includes at least one wiring unit and at least one first switch 21. The wiring unit is used to connect to at least one battery cell 10. The active balancing circuit unit 30 has multiple branches 310. The first end of each branch 310 is connected to the first circuit 20 via a switch assembly, and the second end of each branch 310 is connected to the balancing power supply 40. The control unit 50 is connected to the first switch 21 and the active balancing circuit unit 30 in each first circuit 20. The control unit 50 is used to control the opening and closing of the first switch 21 and the active balancing circuit unit 30, so that at least two branches 310 form a closed second circuit with at least two battery cells 10 and the balancing power supply 40, respectively, to regulate the charge and discharge status of each battery cell 10 and the balancing power supply 40.

[0067] In the embodiment of the present application, the first circuit 20 is connected to the battery cells 10 via a wiring unit to form a passive balancing circuit. The branches 310 in the active balancing circuit unit 30 are connected between the first circuit 20 and the balancing power supply 40, forming a charge-discharge circuit between the battery cells 10 and the balancing power supply 40. This design reduces the direct impact of high voltage on the active balancing circuit. The control unit 50 controls the charge and discharge states of the battery cells 10 and the balancing power supply 40 by switching the first switch 21 and the active balancing circuit unit 30 on and off, thereby achieving energy circulation between the battery cells 10 and the balancing power supply 40. By combining the active balancing circuit with the existing passive balancing circuit, the number of components in the active balancing circuit is reduced, reducing the need for high-voltage and high-precision components, significantly reducing the cost of the active balancing circuit, and thus, the manufacturing cost of the vehicle.

[0068] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0069] 1. By combining the active balancing circuit with the existing passive balancing circuit, the number of components on the active balancing circuit is reduced, the demand for high-voltage and high-precision components is reduced, and the cost of the active balancing circuit is greatly reduced.

[0070] 2. The division of labor and cooperation between the main control chip 520 and the auxiliary control chip 530 constitute a distributed control system, which can perform refined management of different aspects of battery balancing, helping to improve the system's response speed and processing capabilities, while also reducing the burden on the single control unit 50 and improving overall stability.

[0071] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0072] In addition to the above, it should be noted that references to "one embodiment," "another embodiment," "an embodiment," and the like in this specification refer to specific features, structures, or characteristics described in conjunction with that embodiment as included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also falls within the scope of the present invention.

[0073] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0074] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A control circuit for a battery pack, characterized in that: include: a first circuit (20), wherein the first circuit (20) is multiple, and each of the first circuits (20) includes at least one wiring unit and at least one first switch (21), wherein the wiring unit is used to connect to at least one battery cell (10); An active balancing circuit unit (30), the active balancing circuit unit (30) being provided with a plurality of branches (310), a first end of each branch (310) being connected to the first circuit via a switch component, and a second end of each branch (310) being connected to a balancing power supply (40); A control unit (50) is connected to the first switch (21) and the active balancing circuit unit (30) in each of the first circuits. The control unit (50) is used to control the on / off of the first switch (21) and the active balancing circuit unit (30), so that at least two of the branches (310) respectively form a closed second circuit with at least two of the battery cells (10) and the balancing power supply (40), thereby regulating the charge and discharge state of each of the battery cells (10) and the balancing power supply (40).

2. The control circuit of the battery pack according to claim 1, characterized in that: The switch assembly includes a first switch assembly, and the first switch assembly includes: a second switch (311), wherein a first pin (3111) of the second switch (311) is connected to a high potential point of the first circuit, and a second pin (3112) of the second switch (311) is connected to a low potential point of the first circuit; A third switch (312), wherein a fourth pin (3121) of the third switch (312) is connected to an electrode of one of the battery cells, a fifth pin (3122) of the third switch (312) is connected to an electrode of the balancing power supply (40), and a sixth pin (3123) of the third switch (312) is connected to a third pin (3113) of the second switch (311), wherein when at least one of the first circuits (20) forms a closed loop, the second switch (311) and the third switch (312) corresponding to the closed loop are automatically turned on, so that a charge-discharge circuit is formed between the portion of the branch (310) where the second switch (311) and the third switch (312) are located, and at least one of the battery cells (10) and the balancing power supply (40).

3. The control circuit of the battery pack according to claim 2, characterized in that: The second switch (311) and the third switch (312) are both MOS transistors.

4. The control circuit of the battery pack according to claim 2, characterized in that: The switch assembly further includes a second switch assembly, the second switch assembly including a first double-pole relay (314) and a second double-pole relay (315), and, The second end of each branch (310) is provided with a first branch and a second branch, the first branch is connected to the electrode of the balancing power supply (40) through the first double-pole relay (314), and the second branch is connected to the electrode of the balancing power supply (40) through the second double-pole relay (315).

5. The control circuit of the battery pack according to any one of claims 1 to 4, characterized in that: Two first resistors (22) are connected in series on each of the first circuits. Each of the first resistors (22) is arranged in parallel with a diode (23). The current flow direction of one of the diodes (23) is the same as the current flow direction of the first circuit, and the current flow direction of the other diode (23) is opposite to the current flow direction of the first circuit.

6. The control circuit of the battery pack according to any one of claims 1 to 4, characterized in that: Each branch (310) of the active balancing circuit unit (30) is serially connected with a second resistor (313).

7. The control circuit of the battery pack according to claim 4, characterized in that: The control unit (50) comprises: an analog front-end chip (510), the analog front-end chip (510) being connected to the battery cells (10) and the first switch (21), the analog front-end chip (510) being used to collect voltage signals of each battery cell (10) and to control the on / off switching of the first switch (21) according to the voltage signals; A control chip is signal-connected to the analog front-end chip (510), and is used to regulate the voltage of the balanced power supply (40) according to the voltage signal, and to control the on / off of the second switch component according to the voltage signal.

8. The control circuit of the battery pack according to claim 7, characterized in that: The control chip includes: a main control chip (520), the main control chip (520) being signal-connected to the analog front-end chip (510), the main control chip (520) being used to regulate the voltage of the balanced power supply (40) according to the voltage signal; A secondary control chip (530), the secondary control chip (530) being signal-connected to the analog front-end chip (510), the secondary control chip (530) being used to regulate the on-off of the second switch component according to the voltage signal.

9. The control circuit of the battery pack according to claim 1, characterized in that: The control circuit further includes: An isolated power supply, each chip in the control unit (50) is connected to the isolated power supply respectively.

10. A vehicle comprising a battery pack, characterized in that: The control circuit of the battery pack is the control circuit according to any one of claims 1 to 9.

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