Novel battery active equalization circuit

Abstract

The utility model relates to a novel battery active equalization circuit, and belongs to the technical field of battery equalization control. According to the novel battery active equalization circuit, the single battery with the highest voltage in the single batteries in the battery pack is determined through the voltage comparison module, and the voltage of the single battery is controlled to be conducted to be output to the boosting module; the charge pump structure is used for amplifying the received voltage according to the number value multiple of the single batteries so as to match the voltage specification of the battery pack, and transmitting the amplified voltage back to the battery pack to complete the equalization control of the battery pack. According to the utility model, in the process of amplifying the voltage of the single battery with the highest voltage, the charge pump, which is a boosting structure taking a capacitor as an energy transfer device, is particularly adopted, so that the use of an inductor / transformer which is large in size, high in cost and relatively low in energy conversion efficiency is avoided, and the size and the cost of the equalization circuit are effectively reduced; and the energy conversion efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery equalization control technology, and in particular to a novel active battery equalization circuit. Background Technology

[0002] In recent years, an increasing number of products have adopted lithium-ion batteries as their primary power source due to their advantages such as small size, high energy density, no memory effect, long cycle life, and low self-discharge rate. However, lithium-ion batteries also have stringent charging and discharging requirements, and the inconsistencies between individual cells within a battery pack make them prone to overcharging, over-discharging, overcurrent, and short circuits. This can lead to a significant increase in battery pressure and heat, potentially causing sparks, combustion, or even explosions. Therefore, all lithium-ion batteries are equipped with battery balancing management functions to ensure their safety and stability.

[0003] Currently, most commercially available active balancing circuit technologies primarily use inductors / transformers as energy conversion devices. However, transformers suffer from drawbacks such as high cost and large size, while inductors are bulky, have low conversion efficiency, and generate noise. Therefore, developing a novel active battery balancing circuit that is small in size, low in cost, and has high energy conversion efficiency has become an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned technical problems, this utility model provides a novel active battery balancing circuit to solve the technical problems of large size, high cost, and low energy conversion efficiency of existing balancing circuits.

[0005] In a first aspect, this utility model provides a novel battery active balancing circuit, comprising: a voltage comparison module and a boost module;

[0006] The voltage comparison module is provided with a voltage input terminal for receiving the output voltage of each individual cell in the battery pack. The number of voltage input terminals is equal to the number of individual cells, and different voltage input terminals receive different output voltages of individual cells. The voltage comparison module is used to connect the output voltage of the individual cell corresponding to the voltage input terminal with the highest voltage to the voltage output terminal of the voltage comparison module.

[0007] The voltage input terminal of the boost module is connected to the voltage output terminal of the voltage comparator module. The boost module is used to boost the voltage at the voltage input terminal of the boost module by a preset multiple using an internal charge pump submodule, and then conduct the boosted voltage to the voltage output terminal of the boost module. The value of the preset multiple is equal to the number of individual batteries. The voltage output terminal of the boost module is used to connect to the charging terminal of the battery pack.

[0008] Optionally, the voltage comparison module includes a comparison selection submodule and a preset number of controllable on / off switches, the preset number being equal to the number of individual batteries;

[0009] The input terminal of each of the controllable on switches is connected to a different voltage input terminal, and the output terminals of all the controllable on switches are connected to the voltage output terminal of the voltage comparison module.

[0010] The comparison and selection submodule includes the preset number of voltage receiving terminals and control output terminals. Each voltage receiving terminal is connected to a different voltage receiving terminal, and each control output terminal is connected to the control terminal of a different controllable on / off switch.

[0011] Optionally, there are two individual cells, and the comparison selection submodule includes a comparator and an inverter;

[0012] The non-inverting input of the comparator receives the output voltage of the first single cell, the inverting input of the comparator receives the output voltage of the second single cell, the output of the comparator is connected to both the input of the inverter and the control terminal of the controllable on / off switch connected to the first single cell, and the output of the inverter is connected to the control terminal of the controllable on / off switch connected to the second single cell.

[0013] Optionally, the charge pump submodule includes a charge pump switch control module, an on / off switch, a first controllable switch, a second controllable switch, a third controllable switch, a fourth controllable switch, and an energy transfer capacitor;

[0014] The charge pump switch control module controls the control terminals of the on / off switch, the first controllable switch, the second controllable switch, the third controllable switch, and the fourth controllable switch. The input terminal of the charge pump submodule is connected to the voltage input terminal of the boost module. One end of the on / off switch is connected to the input terminal of the charge pump submodule. The other end of the on / off switch is simultaneously connected to one end of the first controllable switch and one end of the second controllable switch. The other end of the first controllable switch is simultaneously connected to one end of the third controllable switch and one end of the energy transfer capacitor. The other end of the third controllable switch is grounded. The other end of the second controllable switch is simultaneously connected to one end of the fourth controllable switch and the other end of the energy transfer capacitor. The other end of the fourth controllable switch is connected to the output terminal of the charge pump submodule.

[0015] Optionally, the boost module includes one less charge pump submodule than the number of individual cells, and the output of the last charge pump submodule is connected to the voltage output of the boost module.

[0016] When there are multiple charge pump submodules, in any two adjacent charge pump submodules, the output terminal of the preceding charge pump submodule is connected to the other end of the on / off switch in the following charge pump submodule.

[0017] Optionally, a sampling resistor is connected in series between the output terminal of the last charge pump submodule and the voltage output terminal of the boost module, and the voltage output terminal of the boost module is connected to the charging terminal of the battery pack through a transistor;

[0018] The boost module also includes a current setting terminal and a current adjustment circuit. The sampling terminal of the current adjustment circuit is connected to the sampling resistor, the output terminal of the current adjustment circuit is connected to the base of the transistor, and the current setting terminal is connected to the control terminal of the current adjustment circuit.

[0019] Optionally, the current adjustment circuit is a battery charging constant current source circuit.

[0020] Optionally, the energy transfer capacitor is a non-polar capacitor.

[0021] Optionally, the on / off switch, the first controllable switch, the second controllable switch, the third controllable switch, and the fourth controllable switch are all MOSFETs.

[0022] Optionally, the voltage output terminal of the boost module is connected to one end of a filter capacitor, and the other end of the filter capacitor is grounded.

[0023] The above scheme has the following beneficial effects:

[0024] This novel active battery balancing circuit, through a voltage comparison module, identifies the cell with the highest voltage among all individual cells in the battery pack. It then controls the conduction of this highest-voltage cell, sending its voltage output to a boost module. The boost module, utilizing its internal charge pump submodule, amplifies the received voltage by a factor of the number of individual cells and transmits the amplified voltage back to the battery pack, thus completing the battery pack balancing control. In the process of amplifying the voltage of the highest-voltage cell, this invention specifically employs a charge pump—a boost structure using capacitors as energy transfer devices—avoiding the use of large, costly, and inefficient inductors / transformers. This solves the technical problems of large size, high cost, and low energy conversion efficiency in existing balancing circuits. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a novel active battery balancing circuit provided in one embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of a charge pump provided in one embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the circuit structure of a voltage comparison module provided in one embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the circuit structure of a boost module provided in one embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the charging process of the energy transfer capacitor in the charge pump submodule in one embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the continued voltage boosting after the energy transfer capacitor in the charge pump submodule is charged, according to one embodiment of this utility model.

[0031] Figure 7 This is a schematic diagram of a preferred circuit structure of the voltage comparison module in one embodiment of the present invention when the battery pack consists of only two individual cells;

[0032] Figure 8 This is a schematic diagram of the preferred circuit structure of the boost module in one embodiment of the present invention when the battery pack consists of only two individual cells. Detailed Implementation

[0033] To make the technical problems, technical solutions and beneficial effects solved by this utility model clearer, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and embodiments.

[0034] It should be understood that the embodiments described below represent essential information to enable those skilled in the art to implement the embodiments and to illustrate the best mode of implementation. Upon reading the following description in conjunction with the accompanying drawings, those skilled in the art will understand the concepts of this disclosure and recognize the applications of these concepts not specifically mentioned herein. It should be understood that these concepts and applications fall within the scope of this disclosure and the appended claims.

[0035] It should also be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of this disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] It should also be understood that when a component is referred to as "connected" or "coupled" to another component, it can be directly connected or coupled to the other component, or there may be intermediate components. Conversely, when an element is referred to as "directly connected" or "directly coupled" to another element, there are no intermediate components.

[0037] It should also be understood that the terms “upper,” “lower,” “left,” “right,” “front,” “back,” “bottom,” “middle,” “center,” “top,” etc., may be used herein to describe various elements, indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are used only for the convenience of describing the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, these elements should not be limited by these terms.

[0038] These terms are used only to distinguish one element from another. For example, a first element may be referred to as the “upper” element, and similarly, a second element may be referred to as the “upper” element depending on the relative orientation of these elements, without departing from the scope of this disclosure.

[0039] To be further understood, the terms “comprising,” “including,” “including,” and / or “include” as used herein specify the presence of the said feature, integer, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0040] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that the terms used herein should be interpreted as having the same meaning as they mean in the context of this specification and related art, and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0041] In one embodiment, a method such as Figure 1 The novel active battery balancing circuit shown includes a voltage comparison module and a boost module.

[0042] Among them, with Figure 1 Taking a battery pack with two cells connected in series as an example, the voltage comparison module is equipped with voltage receiving terminals that can receive the output voltage of each cell in the battery pack. Clearly, the number of voltage receiving terminals is equal to the number of individual cells, and each voltage receiving terminal receives the output voltage of a different individual cell. It should be noted that the voltage compared by each voltage receiving terminal is the voltage of the individual cell itself, not the voltage between the positive terminal and ground of the current individual cell in the battery pack. Specifically... Figure 1As shown, the first voltage receiver receives the output voltage of the first individual battery BAT1, while the second voltage receiver receives the output voltage of the second individual battery BAT2, not the voltage between the positive terminal and ground of the second individual battery BAT2. It should be noted that... Figure 1 The battery pack shown includes two individual cells connected in series for ease of description. The voltage comparison module can have more than two voltage receiving terminals, thus making it suitable for battery packs with more than two individual cells.

[0043] After receiving the voltage of each individual cell in the battery pack through each voltage receiving terminal, the voltage comparison module connects the output voltage of the individual cell corresponding to the voltage receiving terminal with the highest voltage to the voltage output terminal of the voltage comparison module. In other words, it selects and connects the individual cell with the highest voltage to the voltage output terminal of the voltage comparison module, thereby transmitting the voltage to the subsequent boost module.

[0044] The voltage input terminal of the boost module is connected to the voltage output terminal of the voltage comparator module. The boost module uses an internal charge pump submodule to boost the voltage at the voltage input terminal of the boost module by a preset multiple, and then conducts the boosted voltage to the voltage output terminal of the boost module, thereby transmitting it to the charging terminal of the battery pack.

[0045] It is easy to understand that in order to transfer the energy of the single cell with the highest voltage to the entire battery pack, the voltage at the charging end of the battery pack needs to be matched with the overall voltage specification of the battery pack. In other words, the voltage output of the boost module needs to be increased by a multiple of the single cell voltage to the number of single cells in the battery pack. Therefore, the preset multiple value should be equal to the value of the number of single cells.

[0046] The charge pump submodule can be any feasible form of charge pump, and the principle of the charge pump is as follows: Figure 2 As shown, in the first stage, S1 and S2 are closed, S3 and S4 are open, and capacitor C0 is charged to the input voltage V. IN In the second stage, S3 and S4 are closed, and S1 and S2 are open. The voltage drop across capacitor C0 cannot change immediately, and the negative terminal of the capacitor, or low-voltage terminal, suddenly changes from its original ground potential (0) to the input voltage. Therefore, the voltage V0 at the positive terminal of capacitor C0, or the output terminal, jumps to the input voltage V. IN Twice as much.

[0047] Through the switching control of the above switching circuit, the output voltage V0 is achieved to be V IN ×2 means doubling the input voltage. Based on this principle, a charge pump submodule can be constructed.

[0048] In this embodiment, the novel active battery balancing circuit amplifies the voltage of the highest-voltage individual cell to match the overall voltage specifications of the battery pack, thereby achieving voltage balancing control. It specifically employs a charge pump, a boost structure using capacitors as energy transfer devices, which avoids the use of inductors / transformers that are large, costly, and have low energy conversion efficiency. This solves the technical problems of existing balancing circuits, such as large size, high cost, and low energy conversion efficiency.

[0049] In one embodiment, such as Figure 3 As shown, the structure of a voltage comparison module is presented.

[0050] The voltage comparison module includes a comparison selection submodule and a preset number of controllable on / off switches. The preset number is equal to the number of individual batteries. Assuming the battery pack has m individual batteries, the preset number is m. The input terminal of each controllable on / off switch is connected to a different voltage input terminal. Since the number of voltage input terminals is also equal to the number of individual batteries in the battery pack, the number of voltage input terminals in this embodiment is also m. The output terminals of all m controllable on / off switches are connected to the voltage output terminal of the voltage comparison module, so that each controllable on / off switch controls the connection and disconnection between different individual batteries in the battery pack and the voltage output terminal of the voltage comparison module.

[0051] Correspondingly, the comparison and selection submodule also includes a preset number of m voltage receiving terminals and control output terminals. Each voltage input terminal is connected to a different voltage receiving terminal, and each control output terminal is connected to the control terminal of a different controllable on / off switch. It is easy to understand that there is a correspondence between the voltage receiving terminals and control output terminals on the comparison and selection submodule; that is, the m-th voltage receiving terminal is connected to the m-th voltage input terminal on the voltage comparison module corresponding to the m-th single cell, and simultaneously, the m-th control output terminal corresponding to the m-th voltage receiving terminal is connected to the m-th controllable on / off switch k connected in series with the m-th voltage input terminal. m The control terminal.

[0052] The comparison and selection submodule compares the voltages at each voltage receiver terminal, which is essentially comparing the voltages of each individual battery cell. It then identifies the battery cell with the highest voltage and controls the controllable on / off switch connected in series with that cell to turn on. The voltage of the highest-voltage battery cell is then output through the voltage output terminal of the voltage comparison module. The comparison and selection submodule can be implemented in any existing form, such as using common voltage comparison chips like the LM358, LM393, LM358N, LM393N, and LM339 to receive and compare the analog voltage signals output by each individual battery cell, identify the highest-voltage cell, and control the controllable on / off switch connected in series with it, etc.

[0053] This embodiment provides a specific structure of a voltage comparison module, clarifying the composition of such a voltage comparison module that performs voltage judgment on each individual battery cell and controls whether it is connected to the voltage output terminal of the voltage comparison module.

[0054] In one embodiment, such as Figure 4 As shown, the structure of a boost module is presented.

[0055] The boost module consists of several charge pump sub-modules, which include a charge pump switch control module, an on / off switch Qn0, a first controllable switch Qn1, a second controllable switch Qn2, a third controllable switch Qn3, a fourth controllable switch Qn4, and an energy transfer capacitor Cn1.

[0056] The charge pump switch control module controls the control terminals of the on / off switch, the first controllable switch, the second controllable switch, the third controllable switch, and the fourth controllable switch. The input terminal of the charge pump submodule is connected to the voltage input terminal of the boost module. One end of the on / off switch is connected to the input terminal of the charge pump submodule. The other end of the on / off switch is simultaneously connected to one end of the first controllable switch and one end of the second controllable switch. The other end of the first controllable switch is simultaneously connected to one end of the third controllable switch and one end of the energy transfer capacitor. The other end of the third controllable switch is grounded. The other end of the second controllable switch is simultaneously connected to one end of the fourth controllable switch and the other end of the energy transfer capacitor. The other end of the fourth controllable switch is connected to the output terminal of the charge pump submodule.

[0057] Based on the structure of the charge pump submodule described in this embodiment, each charge pump submodule can control the switches within it via the charge pump switch control module to complete the transfer of energy to the energy transfer capacitor. Figure 4 Taking the first charge pump submodule shown as an example:

[0058] First, the charge pump switch control module 1 controls the on / off switch Q10 to turn on, and then... Figure 5 As shown, the second controllable switch Q12 and the third controllable switch Q13 continue to be turned on, and the energy transfer capacitor C11 is charged to the voltage input voltage V of the boost module. IN The potential on the right side, which is connected to the fourth controllable switch Q14, is V. IN Then, as Figure 6 As shown, the charge pump switch control module 1 closes the second controllable switch Q12 and the third controllable switch Q13 while simultaneously turning on the first controllable switch Q11 and the fourth controllable switch Q14. At this time, the potential on the left side of the energy transfer capacitor C11 jumps from 0 to the voltage input voltage V of the boost module. INTherefore, the potential on the right side of the energy transfer capacitor C11 is changed from V IN Jump to 2*V IN .

[0059] But combined Figure 4 It can be seen that, in each charge pump submodule according to Figure 6 As shown, the voltage of its energy transfer capacitor is charged to V. IN However, if the second and third controllable switches are turned off while the first and fourth controllable switches are turned on, and the on / off switches of each charge pump submodule remain on, the energy transfer capacitors in each charge pump submodule will actually form a parallel connection. This will not only fail to increase the overall voltage, but will actually decrease the voltage.

[0060] Therefore, to ensure successful voltage boost, when the boost module has multiple charge pump submodules, the charging of the energy transfer capacitors in the charge pump submodules must be completed, i.e., after the process as follows... Figure 5 After the steps shown, remove the first charge pump submodule from the other charge pump submodules, and proceed as follows: Figure 6 In the steps shown, in addition to turning off the second and third controllable switches, the on / off switch also needs to be turned off, so that the energy transfer capacitors in each charge pump submodule are connected in series between the voltage input terminal and the voltage output terminal of the boost module, and the output terminal of the last charge pump submodule is connected to the voltage output terminal of the boost module to output the boosted voltage.

[0061] Furthermore, in a preferred embodiment, the number of charge pump submodules included in the boost module is one less than the number of individual cells.

[0062] The energy transfer capacitor in each charge pump submodule undergoes, as follows: Figure 5 After each of the steps shown, the voltage will be charged to the voltage input terminal V of the boost module. IN Furthermore, the energy transfer capacitors in each charge pump submodule, connected in series, will reduce the output voltage of the last charge pump submodule to the voltage input voltage V of the boost module. IN The voltage is increased based on the number of series-connected charge pump submodules and the voltage input voltage V of the boost module. IN Therefore, when there are m individual cells in the battery pack, at least n=m-1 charge pump submodules are needed to ensure that the output voltage of the last charge pump submodule matches the overall voltage specification of the battery pack.

[0063] Therefore, in this embodiment, the number of charge pump sub-modules included in the boost module is one less than the number of individual batteries. The output terminal of the last charge pump sub-module is connected to the voltage output terminal of the boost module. When there are multiple charge pump sub-modules, in any two adjacent charge pump sub-modules, the output terminal of the first charge pump module is connected to the other end of the on / off switch in the second charge pump module, that is, the connection terminal connecting the on / off switch with the first switch and the second switch.

[0064] This embodiment minimizes the number of charge pump submodules used in the boost module by reducing the number of individual cells in the battery pack, thereby further reducing the cost and size of the novel active battery balancing circuit of this invention.

[0065] In other embodiments, it is easy to understand that the number of charge pump submodules in the boost module can also be no less than the number of individual cells in the battery pack. In this case, it is only necessary to select a charge pump submodule with one less than the number of individual cells to complete the boost process of the above embodiment, and at the same time, only the second controllable switch and the fourth controllable switch in the unselected charge pump submodule are turned on.

[0066] In one embodiment, such as Figure 7 as well as Figure 8 As shown, a novel active battery balancing circuit structure is presented when the battery pack consists of only two individual cells.

[0067] like Figure 7 As shown, when the battery pack consists of only two individual cells, the comparison selection submodule in the voltage comparison module includes a comparator and an inverter.

[0068] The non-inverting input of the comparator receives the output voltage of the first single cell BAT1, and the inverting input of the comparator receives the output voltage of the second single cell BAT2. The output of the comparator is simultaneously connected to the input of the inverter and the control terminal of the controllable on / off switch K1 connected to the first single cell. The output of the inverter is connected to the control terminal of the controllable on / off switch K2 connected to the second single cell.

[0069] When the output voltage of the first cell BAT1 is greater than the output voltage of the second cell BAT2, the comparator outputs a high level to turn on the controllable switch K1, and the inverter outputs a low level to turn off the controllable switch K2, so that the output voltage of the first cell BAT1 is connected to the voltage output terminal of the voltage comparator module. Conversely, when the output voltage of the first cell BAT1 is less than the output voltage of the second cell BAT2, the comparator outputs a low level to turn off the controllable switch K1, and the inverter outputs a high level to turn on the controllable switch K2, so that the output voltage of the second cell BAT2 is connected to the voltage output terminal of the voltage comparator module.

[0070] The voltage output terminal of the voltage comparator module is connected as follows: Figure 8 The voltage input terminal of the boost module shown is only a charge pump submodule. After boosting the voltage input terminal of the boost module, the voltage output terminal of the boost module is output to the charging terminal of the battery pack to complete the active balancing of the battery. The boost process of the boost module has been described in the above embodiments and will not be repeated in this embodiment.

[0071] In one embodiment, such as Figure 4 as well as Figure 8 As shown, the boost module also has a current adjustment function based on a current adjustment circuit and in conjunction with a sampling resistor, a current setting terminal and a transistor.

[0072] First, a sampling resistor R2 is connected in series between the output terminal of the last charge pump submodule in the boost module, which is also the other side of the fourth switch Qn4 in the nth charge pump submodule, and the voltage output terminal COUT of the boost module. The voltage output terminal COUT of the boost module is connected to the charging terminal VMODULE of the battery pack through a transistor Q1. The boost module also includes a current setting terminal ISET and a current adjustment circuit. The sampling terminal of the current adjustment circuit is connected to the sampling resistor R2 to obtain the current flowing through the current sensing resistor R2 at the voltage output terminal VOUT of the boost module. The output terminal VREG of the current adjustment circuit is connected to the base of the transistor Q1. The current setting terminal ISET is connected to the control terminal of the current adjustment circuit. The current adjustment circuit monitors and provides feedback on the current flowing through the sampling resistor R2 at VOUT, and outputs a current control signal VREG to the external transistor Q1 based on the expected current setting at the control terminal of the current adjustment circuit, thereby controlling the magnitude of the balanced output current, i.e., the output current of the boost module.

[0073] The current magnitude control is achieved by utilizing the current amplification principle of the transistor Q1, specifically by using the base of transistor Q1 to control the collector current. By controlling the magnitude of the output current control signal VREG input to the base of transistor Q1, the magnitude of the output current at the collector of transistor Q1, i.e., the voltage output terminal COUT of the boost module, is controlled.

[0074] The main function of the current adjustment circuit is to sample the current on the sampling resistor R2 and control the output current of the voltage output terminal COUT of the boost module based on the reference current set by the user at the current setting terminal ISET. Its specific circuit structure can adopt any existing implementation form.

[0075] Furthermore, in a preferred embodiment, the current adjustment circuit is a linear constant current adjustment circuit, specifically a battery charging constant current source. The core working principle of the linear constant current source is to control the output current through a linear regulator. The linear regulator is typically a bipolar junction transistor (BJT) or a metal-oxide-semiconductor field-effect transistor (MOSFET), which operates in the amplification region and maintains a constant output current through a negative feedback mechanism.

[0076] For example, if the output current increases, the regulator will increase its on-resistance, thereby reducing the current; conversely, if the output current decreases, the regulator will decrease its on-resistance, thereby increasing the current.

[0077] A battery charging constant current source is a power management circuit specifically designed for battery charging. Its main function is to provide a constant current during the charging process to ensure that the battery can be safely and efficiently charged, while extending its lifespan. Operators can choose any existing battery charging constant current source, such as the SL3038 constant current source, and this embodiment is not specifically limited to it.

[0078] In one embodiment, the energy transfer capacitor is preferably a non-polar capacitor. This is because non-polar capacitors charge and discharge faster than polar capacitors. Therefore, to further improve the working efficiency of the novel battery active balancing circuit of this invention, all energy transfer capacitors are preferably non-polar capacitors.

[0079] Furthermore, to ensure good switching performance and thus balanced control effect, it is preferable that the on / off switch, the first controllable switch, the second controllable switch, the third controllable switch, and the fourth controllable switch are all MOSFETs.

[0080] Furthermore, to maximize the lifespan of the battery pack under the balanced management strategy, a filter capacitor is connected to the voltage output terminal of the boost module to reduce the performance damage of the individual cells within the battery pack caused by the voltage input to the charging terminal. Specifically, the filter capacitor is connected such that one end of the filter capacitor is connected to the voltage output terminal of the boost module, and the other end of the filter capacitor is grounded.

[0081] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A novel active battery balancing circuit, characterized in that, include: Voltage comparator module and boost module; The voltage comparison module is provided with a voltage input terminal for receiving the output voltage of each individual cell in the battery pack. The number of voltage input terminals is equal to the number of individual cells, and different voltage input terminals receive different output voltages of individual cells. The voltage comparison module is used to connect the output voltage of the individual cell corresponding to the voltage input terminal with the highest voltage to the voltage output terminal of the voltage comparison module. The voltage input terminal of the boost module is connected to the voltage output terminal of the voltage comparator module. The boost module is used to boost the voltage at the voltage input terminal of the boost module by a preset multiple using an internal charge pump submodule, and then conduct the boosted voltage to the voltage output terminal of the boost module. The value of the preset multiple is equal to the number of individual batteries. The voltage output terminal of the boost module is used to connect to the charging terminal of the battery pack.

2. The novel battery active balancing circuit according to claim 1, characterized in that, The voltage comparison module includes a comparison selection submodule and a preset number of controllable on switches, the preset number being equal to the number of individual batteries; The input terminal of each of the controllable on switches is connected to a different voltage input terminal, and the output terminals of all the controllable on switches are connected to the voltage output terminal of the voltage comparison module. The comparison and selection submodule includes the preset number of voltage receiving terminals and control output terminals. Each voltage receiving terminal is connected to a different voltage receiving terminal, and each control output terminal is connected to the control terminal of a different controllable on / off switch.

3. The novel active battery balancing circuit according to claim 2, characterized in that, The single cell consists of two cells, and the comparison and selection submodule includes a comparator and an inverter. The non-inverting input of the comparator receives the output voltage of the first single cell, and the inverting input of the comparator receives the output voltage of the second single cell. The output of the comparator is simultaneously connected to the input of the inverter and the control terminal of the controllable on / off switch connected to the first single cell. The output of the inverter is connected to the control terminal of the controllable on / off switch.

4. The novel battery active balancing circuit according to any one of claims 1 to 3, characterized in that, The charge pump submodule includes a charge pump switch control module, an on / off switch, a first controllable switch, a second controllable switch, a third controllable switch, a fourth controllable switch, and an energy transfer capacitor. The charge pump switch control module is connected to the control terminals of the on / off switch, the first controllable switch, the second controllable switch, the third controllable switch, and the fourth controllable switch. The input terminal of the charge pump submodule is connected to the voltage input terminal of the boost module. One end of the on / off switch is connected to the input terminal of the charge pump submodule. The other end of the on / off switch is simultaneously connected to one end of the first controllable switch and one end of the second controllable switch. The other end of the first controllable switch is simultaneously connected to one end of the third controllable switch and one end of the energy transfer capacitor. The other end of the third controllable switch is grounded. The other end of the second controllable switch is simultaneously connected to one end of the fourth controllable switch and the other end of the energy transfer capacitor. The other end of the fourth controllable switch is connected to the output terminal of the charge pump submodule.

5. The novel active battery balancing circuit according to claim 4, characterized in that, The boost module includes one less charge pump submodule than the number of individual cells, and the output terminal of the last charge pump submodule is connected to the voltage output terminal of the boost module. When there are multiple charge pump submodules, in any two adjacent charge pump submodules, the output terminal of the preceding charge pump submodule is connected to the other end of the on / off switch in the following charge pump submodule.

6. The novel active battery balancing circuit according to claim 5, characterized in that, A sampling resistor is connected in series between the output terminal of the last charge pump submodule and the voltage output terminal of the boost module. The voltage output terminal of the boost module is connected to the charging terminal of the battery pack through a transistor. The boost module also includes a current setting terminal and a current adjustment circuit. The sampling terminal of the current adjustment circuit is connected to the sampling resistor, the output terminal of the current adjustment circuit is connected to the base of the transistor, and the current setting terminal is connected to the control terminal of the current adjustment circuit.

7. The novel active battery balancing circuit according to claim 6, characterized in that, The current adjustment circuit is a battery charging constant current source circuit.

8. The novel active battery balancing circuit according to claim 4, characterized in that, The energy transfer capacitor is a non-polar capacitor.

9. The novel active battery balancing circuit according to claim 4, characterized in that, The on / off switch, the first controllable switch, the second controllable switch, the third controllable switch, and the fourth controllable switch are all MOSFETs.

10. The novel battery active balancing circuit according to claim 1, characterized in that, The voltage output terminal of the boost module is connected to one end of a filter capacitor, and the other end of the filter capacitor is grounded.

Images