A battery pack active balancing circuit and method

Abstract

The application provides a battery pack active balancing circuit and method, which determines the single battery needing active balancing in the battery pack, and connects the single battery in the battery pack needing active balancing to a capacitor voltage division balancing circuit and a voltage detection circuit; when the single battery is detected by the voltage detection circuit, the difference between the highest voltage and the lowest voltage of the single battery is greater than a first threshold value, and the switch control circuit controls the active balancing circuit to start the balancing mode; when the single battery is detected by the voltage detection circuit, the difference between the highest voltage of the single battery and the lowest voltage of the single resistor is less than a second threshold value, and the voltage difference between the single battery and the adjacent energy storage capacitor in the battery pack is less than a third threshold value, and the switch control circuit controls the active balancing circuit to end the balancing mode. Through a simple control process, the capacitor voltage division balancing circuit is controlled to actively balance the battery pack, and the problems of high cost, complex control and low balancing precision of the active balancing circuit are solved.

Description

Technical Field

[0001] This invention relates to the field of battery voltage balancing technology, and in particular to an active balancing circuit and method for battery packs. Background Technology

[0002] With the increasingly widespread use of lithium-ion batteries, high-capacity batteries are gradually becoming the direction of new energy technology development. However, the parameters of each lithium-ion battery cannot be guaranteed to be completely consistent during the production process, and there are significant environmental differences during use, leading to excessive differences in individual cells. This results in a decrease in the battery pack's SOC and SOH, affecting the reliability of the battery system. Active balancing circuits can effectively solve this problem.

[0003] Currently, domestic equalization solutions are mainly divided into passive equalization and active equalization. Passive equalization is an energy dissipation type of equalization, with low energy utilization efficiency and serious heat generation. Active equalization is an energy transfer type of equalization, with high energy utilization and less heat generation. Therefore, it has become the main direction for the future development of battery equalization technology. However, the current active equalization circuits have problems such as high cost, complex control, and low equalization accuracy.

[0004] Therefore, the present invention provides a battery pack active balancing circuit and method to solve the problems of high cost, complex control, and low balancing accuracy of active balancing circuits. Summary of the Invention

[0005] In view of this, the present invention provides a battery pack active balancing circuit and method to solve the problems of high cost, complex control, and low balancing accuracy of active balancing circuits.

[0006] To address the aforementioned problems, in a first aspect, the present invention provides an active battery pack balancing circuit, comprising: a capacitor voltage divider balancing circuit, a voltage detection circuit, and a switch control circuit; the capacitor voltage divider balancing circuit is electrically connected to both the switch control circuit and the voltage detection circuit; the switch control circuit is electrically connected to the voltage detection circuit.

[0007] The capacitor voltage divider equalization circuit is used to equalize the charge of individual cells in the battery pack by turning the equalization mode on or off according to the control signal of the switch control circuit.

[0008] The voltage detection circuit is used to detect the voltage of individual cells in the battery pack and the capacitors in the capacitor voltage divider and equalization circuit, and generates a voltage signal for the switch control circuit.

[0009] The switch control circuit is used to receive the voltage signal generated by the voltage detection circuit, and generate a control signal based on the voltage signal to control the capacitor voltage divider equalization circuit to turn the equalization mode on or off.

[0010] In some possible implementations, the switch control circuit is also used to receive the voltage signal generated by the voltage detection circuit, and generate a control signal based on the voltage signal to control the capacitor voltage divider equalization circuit to switch between parallel voltage equalization mode, series voltage equalization mode and series equalization mode.

[0011] In some possible implementations, the capacitor voltage divider circuit includes: a switch array and an energy storage capacitor;

[0012] For N individual cells, the switch array includes 4N switches;

[0013] All the energy storage capacitors are of the same model.

[0014] On the other hand, the present invention also provides a battery pack active balancing method, based on the battery pack active balancing circuit described in any one of the above claims, the method comprising:

[0015] Identify the individual cells in the battery pack that require active balancing, and connect the individual cells in the battery pack that require active balancing to a capacitor voltage divider balancing circuit and a voltage detection circuit.

[0016] When the voltage detection circuit detects that the difference between the highest and lowest voltage of a single cell in the battery pack is greater than a first threshold, the switch control circuit controls the active balancing circuit to activate the balancing mode and balance the charge of the single cells in the battery pack.

[0017] When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than the second threshold, and the voltage difference between a single cell in the battery pack and the adjacent energy storage capacitor is less than the third threshold, the switch control circuit controls the active equalization circuit to end the equalization mode.

[0018] In some possible implementations, the method further includes:

[0019] When the active balancing mode is activated, the switch control circuit controls the capacitor voltage equalization circuit to switch between parallel voltage equalization mode, series voltage equalization mode and series balancing mode based on the voltage of the capacitors in the capacitor voltage equalization circuit detected by the voltage detection circuit.

[0020] In some possible implementations, when the voltage detection circuit detects that the difference between the highest and lowest voltage of a single cell in the battery pack exceeds a first threshold, the switch control circuit controls the active balancing circuit to activate the balancing mode, balancing the charge of the individual cells in the battery pack, including:

[0021] When a single cell in the battery pack is detected by the voltage detection circuit, and the difference between the highest and lowest voltages of the single cell in the battery pack is greater than a first threshold, the voltage detection circuit generates a voltage signal for the switch control circuit.

[0022] The switch control circuit controls the active balancing circuit to activate the balancing mode according to the preset hardware program and voltage signal, thereby balancing the charge of individual cells in the battery pack.

[0023] In some possible implementations, when the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than a second threshold, and the voltage difference between a single cell and its adjacent energy storage capacitor is less than a third threshold, the switch control circuit controls the active equalization circuit to end the equalization mode, including:

[0024] When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than a second threshold, and the voltage difference between a single cell in the battery pack and an adjacent energy storage capacitor is less than a third threshold, the voltage detection circuit generates an end equalization signal to the switch control circuit.

[0025] The switch control circuit controls the active equalization circuit to end the equalization mode according to the preset hardware program and voltage signal.

[0026] In some possible implementations, the active balancing circuit includes: a switch array and an energy storage capacitor; the balancing modes include: series voltage equalization mode, series balancing mode, and parallel voltage equalization mode; the switch control circuit controls the active balancing circuit to activate the balancing mode according to a preset hardware program and a voltage signal, balancing the charge of individual cells in the battery pack, including:

[0027] The switching control circuit controls the array switch in the active equalization circuit to switch between series voltage equalization mode, series equalization mode and parallel voltage equalization mode according to the preset hardware program.

[0028] When the switch control circuit controls the active equalization circuit to start the equalization mode according to the preset hardware program, it controls the switch array to start the parallel voltage equalization mode, series voltage equalization mode and series equalization mode for active equalization according to the switching conditions.

[0029] In some possible implementations, the switch control circuit controls the array switch in the active equalization circuit to switch between series equalization mode, series equalization mode, and parallel equalization mode according to a preset hardware program, including:

[0030] The control switch array connects the energy storage capacitors in series and in parallel across the battery pack, enabling the series voltage equalization mode.

[0031] The control switch array enables the energy storage capacitor to be connected in parallel with each individual cell in the battery pack, thus activating the series balancing mode.

[0032] The control switch array disconnects all energy storage capacitors from the battery pack and connects all energy storage capacitors in parallel, activating the parallel uniform mode.

[0033] In some possible implementations, after the switch control circuit controls the active equalization circuit to activate the equalization mode according to a preset hardware program, the control switch array activates parallel voltage equalization mode, series voltage equalization mode, and series equalization mode for active equalization based on switching conditions, including:

[0034] After the equalization mode is activated, the control switch circuit controls the switch array to switch from the parallel equalization mode to the series equalization mode.

[0035] After the voltage detection circuit detects that the voltage of the energy storage capacitor has reached the average value of the total voltage of the battery pack, the control switch circuit controls the switch array to switch from the series voltage equalization mode to the series equalization mode. The energy storage capacitor is used to equalize the charge of the individual cells in the battery pack. After the equalization is completed, the control switch circuit controls the switch array to switch to the parallel voltage equalization mode.

[0036] Compared with existing technologies, the advantages of this invention include: This invention identifies the individual cells in a battery pack that require active balancing and connects these cells to a capacitor voltage divider balancing circuit and a voltage detection circuit. When the voltage detection circuit detects that the difference between the highest and lowest voltage of an individual cell in the battery pack is greater than a first threshold, the switch control circuit controls the active balancing circuit to activate the balancing mode, balancing the charge of the individual cells in the battery pack. When the voltage detection circuit detects that the difference between the highest voltage of an individual cell and the minimum voltage difference between the resistance of the individual cell in the battery pack is less than a second threshold, and the voltage difference between the individual cell and the adjacent energy storage capacitor is less than a third threshold, the switch control circuit controls the active balancing circuit to terminate the balancing mode. Through a simple control process, the capacitor voltage divider balancing circuit actively balances the battery pack, and the balancing is achieved through capacitor voltage division, resulting in higher balancing accuracy and solving the problems of high cost, complex control, and low balancing accuracy of active balancing circuits. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a structural embodiment of a capacitor voltage divider equalization circuit provided by the present invention;

[0038] Figure 2 A circuit diagram of an embodiment of a capacitor voltage divider equalization circuit provided by the present invention;

[0039] Figure 3 A balanced hierarchical architecture diagram provided by the present invention;

[0040] Figure 4 This is a flowchart of an embodiment of an active battery pack balancing method provided by the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] It should be understood that the illustrative drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or performed simultaneously. Furthermore, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0043] Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0044] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described herein can be combined with other embodiments.

[0045] This invention provides an active balancing circuit for battery packs. Please refer to [link / reference]. Figure 1 , Figure 1 This is a schematic diagram of a battery pack active balancing circuit according to an embodiment of the present invention. The battery pack active balancing circuit includes: a capacitor voltage divider balancing circuit 10, a voltage detection circuit 20, and a switch control circuit 30; the capacitor voltage divider balancing circuit is electrically connected to both the switch control circuit and the voltage detection circuit; the switch control circuit is electrically connected to the voltage detection circuit.

[0046] The capacitor voltage divider equalization circuit is used to equalize the charge of individual cells in the battery pack 40 by turning the equalization mode on or off according to the control signal of the switch control circuit.

[0047] The voltage detection circuit 20 is used to detect the voltage of individual cells in the battery pack 40 and the capacitor in the capacitor voltage divider and equalization circuit 10, and generates a voltage signal for the switch control circuit.

[0048] The switch control circuit 30 is used to receive the voltage signal generated by the voltage detection circuit 20, and generate a control signal based on the voltage signal to control the capacitor voltage divider equalization circuit 10 to turn on or off the equalization mode.

[0049] In the implementation of the present invention, the switch control circuit 30 is also used to receive the voltage signal generated by the voltage detection circuit 20, and generate a control signal according to the voltage signal to control the capacitor voltage equalization circuit 10 to switch between parallel voltage equalization mode, series voltage equalization mode and series equalization mode.

[0050] In an embodiment of the present invention, the capacitor voltage divider equalization circuit 10 includes: a switch array and an energy storage capacitor;

[0051] For N individual cells, the switch array includes 4N switches;

[0052] All the energy storage capacitors are of the same model.

[0053] On the other hand, the present invention also provides a battery pack active balancing method, based on the battery pack active balancing circuit, for details please refer to Figure 4 , Figure 4 A flowchart of an embodiment of the active balancing method for battery packs provided by the present invention includes:

[0054] S201. Determine the individual cells in the battery pack that require active balancing, and connect the individual cells in the battery pack that require active balancing to the capacitor voltage divider balancing circuit and the voltage detection circuit.

[0055] S202. When the voltage detection circuit detects that the difference between the highest and lowest voltage of a single cell in the battery pack is greater than the first threshold, the switch control circuit controls the active balancing circuit to start the balancing mode to balance the charge of the single cells in the battery pack.

[0056] S203. When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than the second threshold, and the voltage difference between a single cell in the battery pack and the adjacent energy storage capacitor is less than the third threshold, the switch control circuit controls the active balancing circuit to end the balancing mode.

[0057] Compared with existing technologies, this invention identifies the individual cells in a battery pack that require active balancing and connects these cells to a capacitor voltage divider balancing circuit and a voltage detection circuit. When the voltage detection circuit detects that the difference between the highest and lowest voltage of an individual cell in the battery pack exceeds a first threshold, a switch control circuit controls the active balancing circuit to activate the balancing mode, balancing the charge of the individual cells in the battery pack. When the voltage detection circuit detects that the difference between the highest voltage and the minimum voltage of an individual cell in the battery pack exceeds a second threshold, and the voltage difference between an individual cell and its adjacent energy storage capacitor exceeds a third threshold, the switch control circuit controls the active balancing circuit to terminate the balancing mode. Through a simple control process, the capacitor voltage divider balancing circuit actively balances the battery pack, achieving higher balancing accuracy by using capacitor voltage division, thus solving the problems of high cost, complex control, and low balancing accuracy associated with traditional active balancing circuits.

[0058] In a specific embodiment, when the voltage detection circuit detects that the difference between the highest and lowest voltage of a single cell in the battery pack is greater than 10mV, the switch control circuit controls the active balancing circuit to activate the balancing mode to balance the charge of the single cells in the battery pack.

[0059] When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than 10mV, and the voltage difference between a single cell in the battery pack and the adjacent energy storage capacitor is less than 5mV, the switch control circuit controls the active equalization circuit to end the equalization mode.

[0060] In an embodiment of the present invention, a battery pack active balancing method further includes:

[0061] When the active balancing mode is activated, the switch control circuit controls the capacitor voltage equalization circuit to switch between parallel voltage equalization mode, series voltage equalization mode and series balancing mode based on the voltage of the capacitors in the capacitor voltage equalization circuit detected by the voltage detection circuit.

[0062] In an embodiment of the present invention, when the voltage detection circuit detects that the difference between the highest and lowest voltages of individual cells in the battery pack is greater than a first threshold, the switch control circuit controls the active balancing circuit to activate the balancing mode to balance the charge of individual cells in the battery pack, including:

[0063] When a single cell in the battery pack is detected by the voltage detection circuit, and the difference between the highest and lowest voltages of the single cell in the battery pack is greater than a first threshold, the voltage detection circuit generates a voltage signal for the switch control circuit.

[0064] The switch control circuit controls the active balancing circuit to activate the balancing mode according to the preset hardware program and voltage signal, thereby balancing the charge of individual cells in the battery pack.

[0065] In an embodiment of the present invention, when the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than a second threshold, and the voltage difference between a single cell and an adjacent energy storage capacitor is less than a third threshold, the switch control circuit controls the active balancing circuit to end the balancing mode, including:

[0066] When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than a second threshold, and the voltage difference between a single cell in the battery pack and an adjacent energy storage capacitor is less than a third threshold, the voltage detection circuit generates an end equalization signal to the switch control circuit.

[0067] The switch control circuit controls the active equalization circuit to end the equalization mode according to the preset hardware program.

[0068] In an embodiment of the present invention, the active balancing circuit includes: a switch array and an energy storage capacitor; the balancing modes include: a series voltage equalization mode, a series balancing mode, and a parallel voltage equalization mode; the switch control circuit controls the active balancing circuit to activate the balancing mode according to a preset hardware program, balancing the voltage of individual cells in the battery pack, including:

[0069] The switching control circuit controls the array switch in the active equalization circuit to switch between series voltage equalization mode, series equalization mode and parallel voltage equalization mode according to the preset hardware program.

[0070] When the switch control circuit controls the active equalization circuit to start the equalization mode according to the preset hardware program, it controls the switch array to start the parallel voltage equalization mode, series voltage equalization mode and series equalization mode for active equalization according to the switching conditions.

[0071] In embodiments of the present invention, the switch control circuit controls the array switch in the active equalization circuit to switch between series voltage equalization mode, series equalization mode, and parallel voltage equalization mode according to a preset hardware program, including:

[0072] The control switch array connects the energy storage capacitors in series and in parallel across the battery pack, enabling the series voltage equalization mode.

[0073] The control switch array enables the energy storage capacitor to be connected in parallel with each individual cell in the battery pack, thus activating the series balancing mode.

[0074] The control switch array disconnects all energy storage capacitors from the battery pack and connects all energy storage capacitors in parallel, activating the parallel uniform mode.

[0075] For a specific embodiment, please refer to Figure 2 , Figure 2 This is a circuit diagram of an embodiment of a capacitor voltage divider circuit. The capacitor voltage divider circuit includes a battery pack 1, a switch group 2, a main positive switch S1, a main load switch S2, series disconnect switches SA1-SAN, and a parallel switching switch group 3.

[0076] The main positive switch S1 is connected to the positive terminal of the first individual cell and the positive terminal of the first energy storage capacitor in the battery pack.

[0077] The main negative switch S1 is connected to the negative terminal of the last individual battery cell and the negative terminal of the last energy storage capacitor.

[0078] The switch group 2 contains N-1 switches, which are connected sequentially to the positive and negative terminals of the corresponding battery pack and energy storage capacitor.

[0079] The series disconnect switch SA1-SAN contains N-1 switches, which are sequentially connected to the negative terminal of the previous energy storage capacitor and the positive terminal of the next energy storage capacitor.

[0080] The parallel switching group 3 contains 2N switches, which sequentially connect the positive and negative terminals of all energy storage capacitors.

[0081] In series voltage equalization mode, switches S1, S2, and SA1-SAN are closed, and parallel switching switch group 3 and switch group 2 are open. The energy storage capacitors receive the average voltage of the battery pack. In series equalization mode, switches S1, S2, SA1-SAN and switch group 2 are closed, and parallel switching switch group 3 is open. At this time, each battery is connected in parallel with its corresponding energy storage capacitor. Batteries with voltages higher than the average voltage of the pack discharge to the energy storage capacitors, and batteries with voltages lower than the average voltage of the pack are charged by the energy storage capacitors. After the battery equalization process is completed, the energy storage capacitor voltages are in a disordered state. In parallel voltage equalization mode, switches S1, S2, SA1-SAN and switch group 2 are open, and parallel switching switch group 3 is closed. At this time, all energy storage capacitors are connected in parallel, and the energy storage capacitor voltages tend to be equal. After switching to series voltage equalization mode, if the total voltage of the energy storage capacitors is greater than that of the battery pack, they will discharge to the battery pack. Eventually, the voltage of each energy storage capacitor reaches the average voltage of the battery pack. If the total voltage of the energy storage capacitors is less than that of the battery pack, they will charge the battery pack. Eventually, the voltage of each energy storage capacitor reaches the average voltage of the battery pack. The equalization circuit cycles through three modes in sequence, and the voltage of each individual cell in each battery pack gradually approaches the average voltage of the battery pack.

[0082] It should be noted that you should refer to [link / reference]. Figure 3 , Figure 3 The present invention provides a balanced hierarchical architecture diagram, wherein the balanced architecture 4 composed of balanced groups contains multiple Figure 2 The capacitor voltage divider balancing circuit shown achieves balancing within the battery pack. The circuit structure of balancing architecture 5 is similar to... Figure 2 The capacitor voltage divider circuit shown is the same, and its operation is the same as... Figure 2 The capacitor voltage divider circuit shown is the same, but the circuit parameters are different. It can achieve equalization between battery packs. This type of equalization architecture can be expanded in multiple stages, thereby improving equalization efficiency and equalization accuracy.

[0083] It should be further noted that the equilibrium group includes... Figure 2 The capacitor voltage divider circuit and its corresponding battery pack are shown.

[0084] In an embodiment of the present invention, after the switch control circuit controls the active equalization circuit to activate the equalization mode according to a preset hardware program, the control switch array activates parallel voltage equalization mode, series voltage equalization mode, and series equalization mode for active equalization according to switching conditions, including:

[0085] After the equalization mode is activated, the control switch circuit controls the switch array to switch from the parallel equalization mode to the series equalization mode.

[0086] After the voltage detection circuit detects that the voltage of the energy storage capacitor has reached the average value of the total voltage of the battery pack, the control switch circuit controls the switch array to switch from the series voltage equalization mode to the series equalization mode. The energy storage capacitor is used to equalize the charge of the individual cells in the battery pack. After the equalization is completed, the control switch circuit controls the switch array to switch to the parallel voltage equalization mode.

[0087] Compared with existing technologies, this invention identifies the individual cells in a battery pack that require active balancing and connects these cells to a capacitor voltage divider balancing circuit and a voltage detection circuit. When the voltage detection circuit detects that the difference between the highest and lowest voltage of an individual cell in the battery pack exceeds a first threshold, a switch control circuit controls the active balancing circuit to activate the balancing mode, balancing the charge of the individual cells in the battery pack. When the voltage detection circuit detects that the difference between the highest voltage and the minimum voltage of an individual cell in the battery pack exceeds a second threshold, and the voltage difference between an individual cell and its adjacent energy storage capacitor exceeds a third threshold, the switch control circuit controls the active balancing circuit to terminate the balancing mode. Through a simple control process, the capacitor voltage divider balancing circuit actively balances the battery pack, achieving higher balancing accuracy by using capacitor voltage division, thus solving the problems of high cost, complex control, and low balancing accuracy associated with traditional active balancing circuits.

[0088] The above provides a detailed description of the active balancing circuit and method for a battery pack proposed in this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, those skilled in the art will recognize that there will be changes in the specific implementation methods and application scope based on the ideas of this invention. The above descriptions are only preferred embodiments of this invention, but the protection scope of this invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this invention should be included within the protection scope of this invention.

Claims

1. A battery pack active balancing circuit, characterized in that, include: The system includes a capacitor voltage divider circuit, a voltage detection circuit, and a switch control circuit; the capacitor voltage divider circuit is electrically connected to both the switch control circuit and the voltage detection circuit; the switch control circuit is electrically connected to the voltage detection circuit. The capacitor voltage divider equalization circuit is used to equalize the charge of individual cells in the battery pack by turning the equalization mode on or off according to the control signal of the switch control circuit. The voltage detection circuit is used to detect the voltage of individual cells in the battery pack and the capacitors in the capacitor voltage divider and equalization circuit, and generates a voltage signal for the switch control circuit. The switch control circuit is used to receive the voltage signal generated by the voltage detection circuit, and generate a control signal based on the voltage signal to control the capacitor voltage divider equalization circuit to turn the equalization mode on or off. The capacitor voltage divider circuit includes: a switch array and an energy storage capacitor; For N individual cells, the switch array includes 4N switches; The equalization modes include: series equalization mode, series equalization mode, and parallel equalization mode; The switch control circuit is used to receive the voltage signal generated by the voltage detection circuit, and generate a control signal based on the voltage signal to control the capacitor voltage divider equalization circuit to turn the equalization mode on or off, including: When the switch control circuit controls the active equalization circuit to start the equalization mode according to the preset hardware program, the control switch array starts the parallel voltage equalization mode, series voltage equalization mode and series equalization mode to perform active equalization according to the switching conditions. The control switch array connects the energy storage capacitors in series and in parallel across the battery pack, enabling the series voltage equalization mode. The control switch array enables the energy storage capacitor to be connected in parallel with each individual cell in the battery pack, thus activating the series balancing mode. The control switch array disconnects all energy storage capacitors from the battery pack and connects all energy storage capacitors in parallel, activating the parallel uniform mode. After the equalization mode is activated, the control switch circuit controls the switch array to switch from the parallel equalization mode to the series equalization mode. After the voltage detection circuit detects that the voltage of the energy storage capacitor has reached the average value of the total voltage of the battery pack, the control switch circuit controls the switch array to switch from the series voltage equalization mode to the series equalization mode. The energy storage capacitor is used to equalize the charge of the individual cells in the battery pack. After the equalization is completed, the control switch circuit controls the switch array to switch to the parallel voltage equalization mode.

2. The active balancing circuit for a battery pack according to claim 1, characterized in that, The switch control circuit is also used to receive the voltage signal generated by the voltage detection circuit, and generate a control signal based on the voltage signal to control the capacitor voltage divider equalization circuit to switch between parallel voltage equalization mode, series voltage equalization mode and series equalization mode.

3. A battery pack active balancing method, based on the battery pack active balancing circuit as described in any one of claims 1-2, characterized in that, The method includes: Identify the individual cells in the battery pack that require active balancing, and connect the individual cells in the battery pack that require active balancing to a capacitor voltage divider balancing circuit and a voltage detection circuit. When the voltage detection circuit detects that the difference between the highest and lowest voltage of a single cell in the battery pack is greater than a first threshold, the switch control circuit controls the active balancing circuit to activate the balancing mode and balance the charge of the single cells in the battery pack. When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than the second threshold, and the voltage difference between a single cell in the battery pack and the adjacent energy storage capacitor is less than the third threshold, the switch control circuit controls the active balancing circuit to end the balancing mode.

4. The active battery pack balancing method according to claim 3, characterized in that, The method further includes: When the active balancing mode is activated, the switch control circuit controls the capacitor voltage equalization circuit to switch between parallel voltage equalization mode, series voltage equalization mode and series balancing mode based on the voltage of the capacitors in the capacitor voltage equalization circuit detected by the voltage detection circuit.

5. The active battery pack balancing method according to claim 3, characterized in that, When the voltage detection circuit detects that the difference between the highest and lowest voltage of a single cell in the battery pack exceeds a first threshold, the switch control circuit controls the active balancing circuit to activate the balancing mode, balancing the charge of the individual cells in the battery pack, including: When a single cell in the battery pack is detected by the voltage detection circuit, and the difference between the highest and lowest voltages of the single cell in the battery pack is greater than a first threshold, the voltage detection circuit generates a voltage signal for the switch control circuit. The switch control circuit controls the active balancing circuit to activate the balancing mode according to the preset hardware program and voltage signal, thereby balancing the charge of individual cells in the battery pack.

6. The active battery pack balancing method according to claim 3, characterized in that, When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than a second threshold, and the voltage difference between a single cell and its adjacent energy storage capacitor is less than a third threshold, the switch control circuit controls the active equalization circuit to end the equalization mode, including: When the voltage detection circuit detects that the voltage difference between the highest voltage of a single cell in the battery pack and the minimum voltage difference between the resistance of a single cell in the battery pack is less than a second threshold, and the voltage difference between a single cell in the battery pack and an adjacent energy storage capacitor is less than a third threshold, the voltage detection circuit generates an end equalization signal to the switch control circuit. The switch control circuit controls the active equalization circuit to end the equalization mode according to the preset hardware program and voltage signal.

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