Active battery balancing devices, chips, battery management systems, and power-consuming equipment

Abstract

The present disclosure provides an active battery balancing device, comprising: multiple battery balancers, each corresponding to a battery cell in a battery pack; the battery balancers including a charge transfer device for transferring charge between the battery cells; and an energy storage capacitor for transferring at least the charge transferred by the charge transfer device to the battery pack. The present disclosure also provides a semiconductor chip, a battery management system, and an electrical device.

Description

Technical Field

[0001] The present disclosure relates to the technical field of active battery balancing, and in particular to an active battery balancing device, a semiconductor chip, a battery management system, and an electrical device. Background Art

[0002] In energy storage systems and new energy vehicles, an increasing number of large-capacity lithium-ion batteries are connected in series to form suitable battery systems to provide the operating voltage required by loads such as new energy vehicle motors and grid-connected converters for energy storage. To ensure proper system operation and maximize the energy storage capacity of all batteries, high consistency requirements are placed on the lithium-ion batteries.

[0003] In a series-connected battery system, since all cells have the same discharge current, Q = ∫Idt, all cells charge or discharge the same amount of charge within the same timeframe. However, lithium battery capacity varies from cell to cell due to process control variations, impurities, and temperature variations. The storage capacity and the voltage corresponding to that capacity vary, and these variations can also vary depending on the battery's age and external temperature. Consequently, these inconsistencies in the cells' inherent characteristics, as well as external conditions (such as temperature), lead to differences in the remaining capacity and terminal voltage under the same charging or discharging conditions. In actual use, in a series-connected battery system, cells with relatively low capacity or those with aging life will first reach the discharge undervoltage point or the full charge point, indicating that the battery is either empty or fully charged. When the discharge undervoltage point is reached or the battery is fully charged, protection measures are needed to stop charging or discharging the battery. At the same time, other lithium-ion batteries in the entire series battery pack system that are relatively large in capacity and in good health have not yet reached the empty or full state and can still discharge or store more charge / energy. Therefore, the allowable discharge and charge energy of the entire series battery pack will be limited by the battery with the lowest capacity or the most severe aging.

[0004] Battery balancing systems are categorized as passive and active. Passive balancing only works during charging, allowing as much charge as possible to be stored in all cells. However, it cannot release as much energy as possible during discharge. Active balancing, due to its high efficiency and energy transfer method, can maximize battery capacity utilization during both charging and discharging.

[0005] Traditional active balancing can use flying capacitors ( Figure 1 ), isolated power supply ( Figure 2), Non-isolated Buck-Boost( Figure 3 ), Isolate Flyback( Figure 4 ) and other solutions.

[0006] like Figure 1 As shown, the control method of the active balancing technology using adjacent flying capacitors is simple, and the transfer capacity per cycle ΔQ = |V BATn+1 -V BATn-1 |*C Fly However, the transfer efficiency of this scheme is affected by the voltage difference, and the balancing accuracy is affected by the voltage drop of the device. The smaller the voltage difference, the lower the balancing efficiency in the later stage of balancing.

[0007] like Figure 2 As shown, the active balancing technology solution using an isolated power supply solution has high and stable energy transfer efficiency. The switch can use a common-source MOSFET or an optically coupled MOSFET, but the number of switches is large, the control is complex, the failure risk is high, the high-voltage MOSFET is expensive, and bidirectional blocking is required. The DC / DC is isolated by a transformer, which has high production costs and high failure costs.

[0008] like Figure 3 As shown in the figure, the energy transfer efficiency of the active balancing technology solution using the non-isolated buck-boost solution is high and stable, but the adjacent energy transfer requires energy to be transmitted one level at a time, which results in large losses. In addition, this solution has a large number of inductors, making EMI design difficult. After failure, short circuits are likely to occur, posing a safety hazard.

[0009] like Figure 4 As shown in the figure, in the active balancing technology solution using isolated Flyback, each battery cell corresponds to a Flyback, and the transferred energy is high and stable. However, the number of transformers is large, the failure risk is high, the production cost is high, and EMI design is difficult. Summary of the Invention

[0010] In order to solve at least one of the above technical problems, the present disclosure provides a battery active balancing device, a semiconductor chip, a battery management system, and an electric device.

[0011] The battery active balancing device, semiconductor chip, battery management system and power-consuming equipment disclosed in the present invention are implemented through the following technical solutions.

[0012] According to one aspect of the present disclosure, a battery active balancing device is provided, comprising:

[0013] Multiple battery balancers, each battery balancer corresponds to a battery cell of the battery pack, and the battery balancer includes:

[0014] a charge transfer device, the charge transfer device transferring the charge of the battery cell; and

[0015] An energy storage capacitor is used to transfer at least the charge transferred by the charge transfer device to a battery pack.

[0016] According to at least one embodiment of the battery active balancing device of the present disclosure, the charge transfer device is arranged in a loop connecting the two ends of the battery cell, one end of the energy storage capacitor is connected to the positive terminal of the battery pack, and the other end of the energy storage capacitor is connected to the negative terminal of the battery pack or grounded.

[0017] According to the battery active balancing device of at least one embodiment of the present disclosure, the charge transfer device charges the energy storage capacitor to increase the voltage of the energy storage capacitor to a first preset voltage greater than the battery pack voltage, and the energy storage capacitor charges the battery pack based on the first preset voltage greater than the battery pack voltage.

[0018] According to the battery active balancing device of at least one embodiment of the present disclosure, the charge transfer device is a multi-stage charge pump.

[0019] According to at least one embodiment of the battery active balancing device disclosed herein, the charge transfer device charges the energy storage capacitor through a first charge transfer direction control device (such as a diode, a field effect transistor, a relay, etc.). When the charge transfer device charges the energy storage capacitor, the first charge transfer direction control device is turned on.

[0020] According to at least one embodiment of the battery active balancing device disclosed herein, a switching device is provided between the battery cell and the charge transfer device. When the switching device is turned on, the battery cell charges the energy storage capacitor via the charge transfer device. When the switching device is turned off, the charge transfer device stops transferring charge to the energy storage capacitor.

[0021] According to the active battery balancing device of at least one embodiment of the present disclosure, the battery pack voltage of the battery pack is reduced to a second preset voltage by the charge transfer device to charge the battery cells.

[0022] According to at least one embodiment of the battery active balancing device disclosed herein, the battery pack voltage of the battery pack is reduced to a second preset voltage via the charge transfer device through a second charge transfer direction control device (e.g., a diode, a field effect transistor, a relay, etc.), and the second charge transfer direction control device is turned on.

[0023] According to at least one embodiment of the battery active balancing device disclosed herein, a switch device is provided between the battery cell and the charge transfer device. When the switch device is turned on, the charge transfer device charges the battery cell. When the switch device is turned off, the charge transfer device stops charging the battery cell.

[0024] According to the battery active balancing device of at least one embodiment of the present disclosure, in the first half cycle of battery cell discharge, the charge transfer device accumulates the charge from the battery cell, and the energy storage capacitor accumulates the charge of the battery pack voltage from the battery pack; in the second half cycle of battery cell discharge, the charge accumulated by the charge transfer device and the charge accumulated by the energy storage capacitor are transferred to the battery pack.

[0025] According to the battery active balancing device of at least one embodiment of the present disclosure, in the first half cycle of charging the battery cell, the charge transfer device and the energy storage capacitor accumulate the charge of the battery pack voltage from the battery pack, and in the second half cycle of charging the battery cell, the charge transfer device releases the charge accumulated by the charge transfer device to the battery cell.

[0026] According to at least one embodiment of the battery active balancing device disclosed herein, the charge transfer device includes a switch group and a charge transfer capacitor. The charge transfer capacitor is connected to the loop at both ends of the battery cell through the switch group to charge the charge transfer capacitor or release the charge accumulated in the charge transfer capacitor to the battery cell, or the charge transfer capacitor is connected in series with the energy storage capacitor to charge the battery pack or accumulate charge from the battery pack voltage of the battery pack.

[0027] The battery active balancing device according to at least one embodiment of the present disclosure further includes a fifth switch, which connects the energy storage capacitor to the battery pack voltage of the battery pack or connects the energy storage capacitor in series with the charge transfer capacitor by turning on or off.

[0028] According to at least one embodiment of the battery active balancing device disclosed herein, the switch group includes a chopping switch, a third switch, and a fourth switch. The charge transfer device also includes a third capacitor and a fourth capacitor. The third capacitor is arranged between the first end of the charge transfer capacitor and the chopping switch, and the fourth capacitor is arranged between the second end of the charge transfer capacitor and the chopping switch.

[0029] According to at least one embodiment of the present disclosure, the battery active balancing device further includes a control & protector, which includes a first current detection unit and a second current detection unit. The first current detection unit is used to monitor the charging current and discharging current of the charge transfer capacitor, and the second current detection unit is used to monitor the charging current and discharging current of the energy storage capacitor.

[0030] According to at least one embodiment of the battery active balancing device disclosed herein, the controller and protector further includes a first voltage acquisition unit, a second voltage acquisition unit, a third voltage acquisition unit, and a fourth voltage acquisition unit. The first voltage acquisition unit and the second voltage acquisition unit acquire the voltage across the charge transfer capacitor to monitor the charge transfer capacitor, the third voltage acquisition unit monitors the battery pack voltage, and the fourth voltage acquisition unit monitors the voltage across the energy storage capacitor.

[0031] According to at least one embodiment of the battery active balancing device disclosed herein, the charge transfer device includes a first charge transfer capacitor, a second charge transfer capacitor, and a switch group. In the first half cycle of battery cell discharge, the first charge transfer capacitor and the second charge transfer capacitor of the charge transfer device are controlled by the switch group to be in a series state to accumulate charge from the battery cell, and the energy storage capacitor accumulates charge of the battery pack voltage from the battery pack; in the second half cycle of battery cell discharge, the charge accumulated by the charge transfer device and the charge accumulated by the energy storage capacitor are transferred to the battery pack.

[0032] According to at least one embodiment of the battery active balancing device of the present disclosure, the charge transfer device is connected to the loop where the two ends of the battery cell are located through a switching device. The switching device includes a first switch and a second switch. The first switch is connected to the positive terminal of the battery cell, and the second switch is connected to the negative terminal of the battery cell.

[0033] According to at least one embodiment of the battery active balancing device of the present disclosure, the switch group includes a sixth switch, a seventh switch, an eighth switch, a third switch, and a fourth switch; the first end of the second charge transfer capacitor is connected to the positive terminal of the battery cell through the first switch; the first end of the second charge transfer capacitor is also connected to the first end of the first charge transfer capacitor through the sixth switch; the second end of the second charge transfer capacitor is connected to the first end of the first charge transfer capacitor through the seventh switch, and the second end of the second charge transfer capacitor is also connected to the second end of the first charge transfer capacitor through the eighth switch; and the second end of the first charge transfer capacitor is also connected to the negative terminal of the battery cell through the second switch.

[0034] According to at least one embodiment of the battery active balancing device of the present disclosure, in the second half cycle of the battery cell discharge, the first charge transfer capacitor and the second charge transfer capacitor of the charge transfer device are connected in parallel under the control of the switch group, and are connected in series with the energy storage capacitor under the control of the fifth switch to transfer the charge accumulated by the charge transfer device and the charge accumulated by the energy storage capacitor to the battery pack.

[0035] According to at least one embodiment of the present disclosure, the active battery balancing device is in the form of a semiconductor chip.

[0036] According to another aspect of the present disclosure, a semiconductor chip is provided, on which any of the above-mentioned active battery balancing devices is formed.

[0037] According to another aspect of the present disclosure, a battery management system is provided, comprising: the battery active balancing device described in any one of the above items, wherein the battery active balancing device actively balances a battery pack.

[0038] According to another aspect of the present disclosure, there is provided an electric device, comprising: a battery pack; and the above-mentioned battery management system, wherein the battery management system actively balances the battery pack at least based on a battery active balancing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0040] Figure 1 This is a schematic diagram of an active balancing technology solution using adjacent flying capacitors in the prior art.

[0041] Figure 2 This is a schematic diagram of an active balancing technology solution using an isolated power supply solution in the prior art.

[0042] Figure 3 This is a schematic diagram of an active balancing technology solution using a non-isolated buck-boost solution in the prior art.

[0043] Figure 4 This is a schematic diagram of an active balancing technology solution using an isolated Flyback solution in the prior art.

[0044] Figure 5 FIG. 1 is a circuit diagram of a battery equalizer of an active battery balancing device according to an embodiment of the present disclosure.

[0045] Figure 6 FIG. 1 is a circuit structure diagram of a battery equalizer of an active battery balancing device according to another embodiment of the present disclosure.

[0046] Figure 7 FIG. 1 is a circuit structure diagram of a battery equalizer of an active battery balancing device according to another embodiment of the present disclosure.

[0047] Figure 8FIG. 1 is a circuit structure diagram of a battery equalizer of an active battery balancing device according to another embodiment of the present disclosure.

[0048] Figure 9 FIG. 1 is a circuit structure diagram of a battery equalizer of an active battery balancing device according to another embodiment of the present disclosure.

[0049] Figure 10 yes Figure 9 FIG. 2 shows the driving signal control timing of the battery balancer. FIG.

[0050] Figure 11 and Figure 12 Shown respectively Figure 9 The working status of the battery balancer in the charge accumulation period (upper half cycle) and the charge release period (lower half cycle).

[0051] Figure 13 FIG. 1 is a circuit structure diagram of a battery equalizer of an active battery balancing device according to another embodiment of the present disclosure.

[0052] Figure 14 yes Figure 13 FIG. 2 shows the driving signal control timing of the battery balancer. FIG.

[0053] Figure 15 and Figure 16 Shown respectively Figure 13 The working status of the battery balancer in the charge accumulation period (upper half cycle) and the charge release period (lower half cycle).

[0054] Figure 17 This is a schematic block diagram of the structure of a battery active balancing device according to an embodiment of the present disclosure.

[0055] Figure 18 This is a schematic block diagram of the structure of an electrical device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0056] The present disclosure will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the relevant content and are not intended to limit the present disclosure. It should also be noted that, for ease of description, only the portions relevant to the present disclosure are shown in the accompanying drawings.

[0057] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present disclosure can be combined with each other. The technical solutions of the present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] Unless otherwise stated, the exemplary embodiments / examples shown are to be understood as providing exemplary features of various details of some ways in which the technical concepts of the present disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of the various embodiments / examples may be further combined, separated, interchanged, and / or rearranged without departing from the technical concepts of the present disclosure.

[0059] The use of cross hatching and / or shading in the accompanying drawings is generally used to make the boundaries between adjacent components clear. As such, unless otherwise indicated, the presence or absence of cross hatching or shading does not convey or indicate any preference or requirement for the specific materials, material properties, dimensions, proportions, commonalities between the components shown, and / or any other characteristics, attributes, properties, etc. of the components. In addition, in the accompanying drawings, the sizes and relative sizes of the components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments can be implemented differently, the specific process sequence can be performed in a different order than described. For example, two successively described processes can be performed substantially simultaneously or in an order opposite to the order described. In addition, the same figure numbers represent the same components.

[0060] When a component is referred to as being “on,” “over,” “connected to,” or “coupled to” another component, the component may be directly on, directly connected to, or directly coupled to the other component, or intervening components may be present. However, when a component is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another component, there are no intervening components present. For this purpose, the term “connected” may refer to a physical connection, an electrical connection, etc., with or without intervening components.

[0061] For descriptive purposes, the present disclosure may use spatially relative terms such as "below," "beneath," "under," "down," "above," "upper," "above," "higher," and "side (e.g., in a "sidewall")," to describe the relationship of one component to another (other) component as shown in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the drawings is turned over, a component described as "below" or "beneath" another component or feature would then be positioned "above" the other component or feature. Thus, the exemplary term "below" can encompass both the "above" and "below" orientations. Furthermore, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and as such, the spatially relative descriptors used herein should be interpreted accordingly.

[0062] The terms used herein are for the purpose of describing specific embodiments and are not intended to be restrictive. As used herein, unless the context clearly indicates otherwise, the singular forms "one (kind, person)" and "said (the)" are also intended to include plural forms. In addition, when the terms "comprise" and / or "include" and their variations are used in this specification, the features, integral bodies, steps, operations, parts, assemblies and / or their groups stated are explained, but the presence or addition of one or more other features, integral bodies, steps, operations, parts, assemblies and / or their groups is not excluded. It should also be noted that, as used herein, the terms "substantially", "approximately" and other similar terms are used as approximate terms and not as degree terms, so that they are used to explain the inherent deviations of the measured values, calculated values and / or the values provided that will be recognized by those of ordinary skill in the art.

[0063] Combined with the following Figures 1 to 18 The battery active balancing device, semiconductor chip, battery management system and power-consuming equipment disclosed in the present invention are described in detail.

[0064] like Figure 5 As shown, the battery pack 20 includes a plurality of battery cells 201 connected in series, and each battery cell 201 (CELL) corresponds to a charge transfer device 101 and a storage capacitor 102. In the first half cycle, the battery cell 201 (CELL) charges the energy storage capacitor 102 through the charge transfer device 101. The charge transfer device 101 can increase the battery cell voltage VCELL of the battery cell 201 to a preset voltage greater than the battery pack voltage VBAT (for example, the voltage is increased according to a ratio of 1:X1, and the preset voltage is VCELL*X1). In the second half cycle, the energy storage capacitor 102 charges the battery pack 20 based on the preset voltage (VCELL*X1) greater than the battery pack voltage VBAT, thereby realizing the discharge of the battery cell 201 to charge the battery pack 20.

[0065] Preferably, the charge transfer device 101 may be a multi-stage charge pump.

[0066] like Figure 5 As shown, according to one embodiment of the present disclosure, a battery active balancing device 1000 includes a plurality of battery balancers 100, each battery balancer 100 corresponds to a battery cell 201, and the battery balancer 100 includes a charge transfer device 101 and an energy storage capacitor 102. The charge transfer device 101 charges the energy storage capacitor 102 based on the battery cell voltage VCELL of the battery cell 201 to increase the voltage of the energy storage capacitor 102 to a first preset voltage greater than the battery pack voltage VBAT. The energy storage capacitor 102 charges the battery pack 20 based on the first preset voltage greater than the battery pack voltage VBAT.

[0067] According to a preferred embodiment of the present disclosure, the charge transfer device 101 controls the direction of the charge transfer by a first charge transfer direction control device ( Figure 5 Taking first diode 103 as an example (the first charge transfer direction control device can also be a device that controls the conduction direction of a circuit, such as a field-effect transistor or a relay), the energy storage capacitor 102 is charged. When the charge transfer device 101 charges the energy storage capacitor 102, the first diode 103 is forward-conducted. When the energy storage capacitor 102 is charged to a first predetermined voltage greater than the battery pack voltage VBAT, the charge transfer device 101 stops charging the energy storage capacitor 102.

[0068] According to a preferred embodiment of the present disclosure, a switching device is provided between the battery cell 201 and the charge transfer device 101. Through the switching device, the battery cell 201 is controlled to charge the energy storage capacitor 102 via the corresponding charge transfer device 101. When the switching device is disconnected, the battery cell 201 stops charging the energy storage capacitor 102.

[0069] Preferably, the switch device includes two switch parts 104 , which are respectively arranged at the positive terminal and the negative terminal of the battery unit 201 , and the charge transfer device 101 is arranged between the two switch parts 104 .

[0070] like Figure 5 As shown, the battery cell voltage VCELL of a single battery cell 201 is discharged to charge the battery pack 20. The conditions that need to be met are:

[0071]

[0072] Where n represents the nth switch in the multi-stage charge pump ( Figure 5 Switches S1, S2, S3, S4, S6, S7, S8 are shown in FIG. D is the forward voltage of the first diode 103. SWn,ON Indicates the resistance of the switch when the nth switch is on (closed), i n is the current flowing through the switch. V D is the forward voltage of the diode 103.

[0073] On the basis of the above embodiment, preferably, reference Figure 6 The active battery balancing device 1000 includes a battery balancer 300, which includes a charge transfer device 301 and an energy storage capacitor 302. The battery pack voltage VBAT is reduced to a second predetermined voltage (for example, by reducing VBAT to a predetermined voltage slightly higher than the battery cell voltage VCELL using a ratio of X2:1) via the charge transfer device 301 to charge the battery cell 201.

[0074] In this embodiment, the battery pack voltage VBAT is controlled by the second charge transfer direction control device ( Figure 6 The second diode 303 is taken as an example) and the voltage thereof is reduced to a second preset voltage through the charge transfer device 301, and the second diode 303 is forward-conducted.

[0075] Preferably, a switch device is provided between the battery cell 201 and the charge transfer device 301 , and the charge transfer device 301 is controlled by the switch device to charge the battery cell 201 . When the switch device is disconnected, the charging of the battery cell 201 is stopped.

[0076] Preferably, the switch device includes two switch parts 304 , which are respectively arranged at the positive terminal and the negative terminal of the battery unit 201 , and the charge transfer device 301 is arranged between the two switch parts 304 .

[0077] like Figure 6 As shown, when the battery pack voltage VBAT is discharged and the single battery cell 201 is charged by the multi-stage charge pump, the conditions that need to be met are:

[0078]

[0079] Among them, V D is the forward voltage of the diode 303.

[0080] The active battery balancing device 1000 disclosed in the present invention may include multiple battery balancers 100 or multiple battery balancers 300 , and is used only as an active balancing circuit for unidirectional charging or unidirectional discharging.

[0081] The active battery balancing device 1000 of the present disclosure may also include a plurality of battery balancers 100 and a plurality of battery balancers 300 , and serve as a bidirectional (charging direction and discharging direction) active balancing circuit.

[0082] Preferably, the cell balancer 100 is further provided with a voltage regulator 105 (eg, LDO), and the cell balancer 300 is further provided with a voltage regulator 305 (eg, LDO).

[0083] In the above embodiment, the switch section 104 , the switch section 304 and the switches ( S1 , S2 , S3 , S4 , S6 , S7 , S8 ) in the multi-stage charge pump are all MOSFETs.

[0084] The battery pack 20 typically consists of four to six battery cells 201 connected in series. To increase the cell voltage VCELL of a single battery cell 201 above the pack voltage VBAT of the battery pack 20, it is necessary to adjust the ratio between the number of multi-stage charge pump stages and the number of battery cells 201. A larger number of multi-stage charge pump stages requires a larger number of switches (MOSFETs), resulting in greater energy loss.

[0085] According to another preferred embodiment of the present disclosure, referring to Figure 7 The active battery balancing device 1000 includes a plurality of battery balancers 400 , one corresponding to each battery cell 201 . The battery balancer 400 includes a first capacitor C1 , a second capacitor C2 , and a switch group. The switch group includes a first switch S1 , a second switch S2 , a third switch S3 , a fourth switch S4 , and a fifth switch S5 .

[0086] The battery balancer 400 operates as follows: in the first half cycle, the battery cell voltage VCELL of a single battery cell 201 charges the first capacitor C1, while VBAT charges the second capacitor C2. That is, the first switch S1, the second switch S2, and the fifth switch S5 are closed (conducting), and the third switch S3 and the fourth switch S4 are opened.

[0087] The first half of the cycle meets the following conditions:

[0088] V C1 =V CELL (3)

[0089] V C2 =V BAT (4)

[0090] In the second half cycle, the first capacitor C1 and the second capacitor C2 are connected in series (the first switch S1, the second switch S2, and the fifth switch S5 are disconnected, and the third switch S3 and the fourth switch S4 are closed) to discharge the battery pack 20 together, and release the charge stored in the first capacitor C1 and the second capacitor C2 to the battery pack voltage VBAT of the battery pack 20.

[0091] The second half cycle meets the conditions:

[0092]

[0093] ΔV=V C1 +V C2 -V BAT =V CELL (6)

[0094]

[0095]

[0096]

[0097] ΔVC1 is the voltage change during the process of the first capacitor C1 releasing the stored charge to the battery pack 20 , and ΔVC2 is the voltage change during the process of the second capacitor C2 releasing the stored charge to the battery pack 20 .

[0098] According to the above formula (6), a single battery cell 201 releases energy when discharging. Since the battery cell voltage of the single battery cell 201 is in the range of 2V-4.5V, when the first capacitor and the second capacitor are discharged, the voltage difference between VCELL and VBAT is large, which will cause a large current spike (peak current).

[0099] In this embodiment, the battery balancer 400 includes a charge transfer device, which includes a charge transfer capacitor (ie, a first capacitor C1 ), and a second capacitor C2 used as an energy storage capacitor.

[0100] According to a further preferred embodiment of the present disclosure, referring to Figure 8 The active battery balancing device 1000 includes a plurality of battery balancers 400 , one corresponding to each battery cell 201 . The battery balancer 400 includes a first capacitor C1 , a second capacitor C2 , a third capacitor C3 , a fourth capacitor C4 , and a switch group. The switch group includes a chopping switch 401 , a third switch S3 , a fourth switch S4 , and a fifth switch S5 .

[0101] In this embodiment, the charging voltage VC1 of the first capacitor C1 is controlled by adding the third capacitor C3 and the fourth capacitor C4. VC1 is controlled by the chopping switch 401, thereby indirectly controlling the voltage difference between VC1-VC2 and VBAT to control the peak current.

[0102] In this embodiment, the cell balancer 400 includes a charge transfer device, which itself includes a charge transfer capacitor (a first capacitor C1 ).

[0103] In this embodiment, in the first half cycle, the single battery cell 201 charges C1, and VBAT charges the second capacitor C2 at the same time. In the second half cycle, the first capacitor C1 and the second capacitor C2 are connected in series to discharge the battery pack 20 together, releasing the charge stored in the first capacitor C1 and the second capacitor C2 to the battery pack voltage VBAT of the battery pack 20.

[0104] Figure 9 FIG. 1 is a structural diagram of a battery equalizer 400 of a battery active equalization device 1000 according to another preferred embodiment of the present disclosure. Figure 7 Based on the illustrated cell balancer 400, the cell balancer 400 further includes a control & protector 900. The control & protector 900 may be in the form of a control chip having pre-set control & protection logic. The control & protector 900 includes a first current detection unit 901 and a second current detection unit 902. The first current detection unit 901 is used to monitor the charging current and discharging current of the first capacitor C1, and the second current detection unit 902 is used to monitor the charging current and discharging current of the second capacitor C2.

[0105] The control & protector 900 also includes a first voltage acquisition unit 903, a second voltage acquisition unit 904, a third voltage acquisition unit 905 and a fourth voltage acquisition unit 906. The first voltage acquisition unit 903 and the second voltage acquisition unit 904 acquire the voltage across the first capacitor C1 to monitor the first capacitor C1, the third voltage acquisition unit 905 monitors the battery pack voltage VBAT, and the fourth voltage acquisition unit 906 monitors the voltage across the second capacitor C2.

[0106] Preferably, the control & protector 900 generates corresponding control signals based on the above voltage monitoring values and current monitoring values to control the closing or opening of the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, and the fifth switch S5.

[0107] Figure 10 The driving signal control timing of this embodiment is shown. The driving signal can be generated by Figure 9 The control & protection device 900 is generated. Each switch is preferably a MOS tube switch.

[0108] Figure 10 In the figure, tf is the fall time, tr is the rise time, td is the delay time, and tw is the length of one cycle.

[0109] Figure 11 and Figure 12 Schematic diagrams of the working status of the battery balancer 400 during the charge accumulation period (upper half cycle) and the charge release period (lower half cycle) are respectively shown. The entire cycle realizes the use of the first capacitor C1 to transfer the charge of a single battery cell (Cell n) to the battery pack 20, realizing active balanced energy transfer.

[0110] According to a more preferred embodiment of the present disclosure, referring to Figure 13 The active battery balancing device 1000 includes a plurality of cell balancers 400 , one corresponding to each battery cell 201 . The cell balancer 400 includes a first capacitor C1 , a second capacitor C2 , a third capacitor C3 , and a switch group. The switch group includes a first switch S1 , a second switch S2 , a third switch S3 , a fourth switch S4 , a fifth switch S5 , a sixth switch S6 , a seventh switch S7 , and an eighth switch S8 .

[0111] In this embodiment, the battery balancer 400 includes a charge transfer device, which includes charge transfer capacitors ( C1 , C3 ), and a second capacitor C2 is used as an energy storage capacitor.

[0112] Figure 14 FIG. 4 shows a driving signal control timing of the battery balancer 400 of the present disclosure.

[0113] Figure 15 and Figure 16 Schematic diagrams of the working status of the battery balancer 400 during the charge accumulation period (upper half cycle) and the charge release period (lower half cycle) are respectively shown. The entire cycle realizes the use of the first capacitor C1 and the third capacitor C3 to transfer the charge of a single battery cell (Cell n) to the battery pack 20, realizing active balanced energy transfer.

[0114] exist Figure 15 The following conditions are met:

[0115] V Celln =V C1 +V C3 +i C1 *R tot

[0116] R tot =R int +R S1 +R S7 +R S2 +R C3ser +R C1ser

[0117]

[0118] V BAT =V C2 +i C2 *(R C2ser +R S5 )

[0119]

[0120] Among them, R int is the internal resistance of the battery cell 201.

[0121] The battery active balancing device 1000 of the present disclosure may include a plurality of battery balancers 400 ( Figure 7 Battery balancer 400, Figure 8 Battery balancer 400, Figure 9 Battery balancer 400 or Figure 13 The battery equalizer 400 shown in FIG. Figure 17 .

[0122] According to another aspect of the present disclosure, a battery management system is provided, comprising the battery active balancing device 1000 according to any one of the above embodiments.

[0123] According to a technical solution of the present disclosure, a battery active balancing device 1000 includes:

[0124] Multiple battery balancers (100, 300, 400), each battery balancer corresponds to a battery cell 201 of the battery pack 20, and the battery balancer includes:

[0125] A charge transfer device, which transfers the charge of the battery cell 201; and an energy storage capacitor (102, 302, C2), which at least transfers the charge transferred by the charge transfer device to the battery pack 20.

[0126] The number of battery balancers is more than two.

[0127] According to another technical solution of the present disclosure, on the basis of the above technical solution, the charge transfer device 101 of the battery equalizer is arranged in a loop connecting the two ends of the battery cell 201, one end of the energy storage capacitor 102 is connected to the positive terminal of the battery pack 20, and the other end of the energy storage capacitor 102 is connected to the negative terminal of the battery pack 20 or grounded.

[0128] According to another technical solution of the present disclosure, on the basis of the above technical solution, the charge transfer device 101 of the battery balancer increases the battery cell voltage VCELL of the battery cell 201 to a first preset voltage greater than the battery pack voltage VBAT to charge the energy storage capacitor 102, and the energy storage capacitor 102 charges the battery pack 20 based on the first preset voltage greater than the battery pack voltage VBAT.

[0129] According to another technical solution of the present disclosure, on the basis of the above technical solution, the charge transfer device 101 of the battery equalizer is a multi-stage charge pump.

[0130] According to another technical solution of the present disclosure, on the basis of the above technical solution, the charge transfer device 101 of the battery balancer charges the energy storage capacitor 102 through the diode 103. When the charge transfer device 101 charges the energy storage capacitor 102, the diode 103 is forward-conducted.

[0131] According to another technical solution of the present disclosure, on the basis of the above technical solution, a switching device is provided between the battery cell 201 and the charge transfer device 101. When the switching device is turned on, the battery cell 201 charges the energy storage capacitor 102 via the charge transfer device 101. When the switching device is turned off, the charge transfer device 101 stops transferring charge to the energy storage capacitor 102.

[0132] According to another technical solution of the present disclosure, the battery pack voltage of the battery pack 20 is reduced to a second preset voltage by the charge transfer device 301 to charge the battery cell 201 .

[0133] According to another technical solution of the present disclosure, the battery pack voltage of the battery pack 20 is reduced to a second preset voltage via the charge transfer device 301 through the diode 303 , and the diode 303 is forward-conducted.

[0134] According to another technical solution of the present disclosure, a switching device is provided between the battery cell 201 and the charge transfer device 301. When the switching device is turned on, the charge transfer device 301 charges the battery cell 201. When the switching device is turned off, the charge transfer device 301 stops charging the battery cell 201.

[0135] According to another technical solution of the present disclosure, in the first half cycle of the discharge of the battery cell 201, the charge transfer device of the battery equalizer 400 accumulates the charge from the battery cell 201, and the energy storage capacitor (C2) accumulates the charge of the battery pack voltage from the battery pack 20; in the second half cycle of the discharge of the battery cell 201, the charge accumulated by the charge transfer device and the charge accumulated by the energy storage capacitor (C2) are transferred to the battery pack.

[0136] According to another technical solution of the present disclosure, in the first half cycle of charging the battery cell, the charge transfer device and the energy storage capacitor (C2) of the battery balancer 400 accumulate the charge of the battery pack voltage from the battery pack, and in the second half cycle of charging the battery cell 201, the charge transfer device releases the charge accumulated by the charge transfer device to the battery cell 201 (CELL).

[0137] According to another technical solution of the present disclosure, the charge transfer device of the battery equalizer 400 includes a switch group and a charge transfer capacitor (C1). The charge transfer capacitor (C1) is connected to the loop at both ends of the battery cell 201 through the switch group (S1, S2, S3, S4) to charge the charge transfer capacitor (C1) or release the charge accumulated in the charge transfer capacitor (C1) to the battery cell, or the charge transfer capacitor (C1) is connected in series with the energy storage capacitor (C2) to charge the battery pack or accumulate the charge of the battery pack voltage from the battery pack.

[0138] According to another technical solution of the present disclosure, the battery equalizer 400 further includes a fifth switch (C5), which connects the energy storage capacitor (C2) to the battery pack voltage of the battery pack or connects the energy storage capacitor (C2) in series with the charge transfer capacitor (C1) by turning on or off.

[0139] According to another technical solution of the present disclosure, the switch group of the cell balancer 400 includes a chopping switch 401, a third switch (C3), and a fourth switch (C4). The charge transfer device also includes a third capacitor (C3) and a fourth capacitor (C4). The third capacitor (C3) is arranged between the first end of the charge transfer capacitor (C1) and the chopping switch 401, and the fourth capacitor (C4) is arranged between the second end of the charge transfer capacitor (C1) and the chopping switch 401.

[0140] According to another technical solution of the present disclosure, the battery balancer 400 further includes a control & protector 900, which includes a first current detection unit 901 and a second current detection unit 902. The first current detection unit 901 is used to monitor the charging current and discharging current of the charge transfer capacitor (C1), and the second current detection unit 902 is used to monitor the charging current and discharging current of the energy storage capacitor (C2).

[0141] According to another technical solution of the present disclosure, the control & protector 900 of the battery balancer 400 further includes a first voltage acquisition unit 903, a second voltage acquisition unit 904, a third voltage acquisition unit 905, and a fourth voltage acquisition unit 906. The first voltage acquisition unit 903 and the second voltage acquisition unit 904 acquire the voltage across the charge transfer capacitor (C1) to monitor the charge transfer capacitor (C1), the third voltage acquisition unit 905 monitors the battery pack voltage, and the fourth voltage acquisition unit 906 monitors the voltage across the energy storage capacitor.

[0142] According to another technical solution of the present disclosure, the charge transfer device of the battery equalizer 400 includes a first charge transfer capacitor (C1), a second charge transfer capacitor (C3) and a switch group (S6, S7, S8, S3, S4). In the first half cycle of the discharge of the battery cell 201, the first charge transfer capacitor and the second charge transfer capacitor of the charge transfer device are in a series state under the control of the switch group to accumulate the charge from the battery cell 201, and the energy storage capacitor (C2) accumulates the charge of the battery pack voltage from the battery pack; in the second half cycle of the discharge of the battery cell 201, the charge accumulated by the charge transfer device and the charge accumulated by the energy storage capacitor are transferred to the battery pack.

[0143] According to another technical solution of the present disclosure, the charge transfer device of the battery equalizer 400 is connected to the loop at both ends of the battery cell through a switching device (S1, S2). The switching device includes a first switch and a second switch. The first switch is connected to the positive terminal of the battery cell, and the second switch is connected to the negative terminal of the battery cell.

[0144] According to another technical solution of the present disclosure, the switch group of the battery equalizer 400 includes a sixth switch, a seventh switch, an eighth switch, a third switch and a fourth switch; the first end of the second charge transfer capacitor (C3) is connected to the positive terminal of the battery cell through the first switch; the first end of the second charge transfer capacitor (C3) is also connected to the first end of the first charge transfer capacitor through the sixth switch; the second end of the second charge transfer capacitor (C3) is connected to the first end of the first charge transfer capacitor through the seventh switch, and the second end of the second charge transfer capacitor (C3) is also connected to the second end of the first charge transfer capacitor through the eighth switch; the second end of the first charge transfer capacitor is also connected to the negative terminal of the battery cell through the second switch.

[0145] According to another technical solution of the present disclosure, in the second half cycle of the discharge of the battery cell 201, the first charge transfer capacitor and the second charge transfer capacitor of the charge transfer device are connected in parallel under the control of the switch group, and are connected in series with the energy storage capacitor under the control of the fifth switch to transfer the charge accumulated by the charge transfer device and the charge accumulated by the energy storage capacitor to the battery pack.

[0146] According to another technical solution of the present disclosure, the active battery balancing device 1000 is in the form of a semiconductor chip.

[0147] According to another technical solution of the present disclosure, a semiconductor chip is formed with the battery active balancing device 1000 of any of the above technical solutions.

[0148] According to another technical solution of the present disclosure, an electric device includes: a battery pack; and the above-mentioned battery management system, wherein the battery management system actively balances the battery pack 20 based on at least the battery active balancing device 1000. Figure 18 .

[0149] Among them, the electrical equipment may be electric vehicles, etc.

[0150] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present disclosure. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine different embodiments / methods or examples described in this specification and the features of different embodiments / methods or examples, unless they are contradictory.

[0151] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0152] Those skilled in the art will appreciate that the above embodiments are merely intended to clearly illustrate the present disclosure and are not intended to limit the scope of the present disclosure. Other changes or modifications may be made based on the above disclosure, and such changes or modifications are still within the scope of the present disclosure.

Claims

1. A battery active balancing device, characterized in that: include: Multiple battery balancers, each battery balancer corresponds to a battery cell of the battery pack, and the battery balancer includes: a charge transfer device, the charge transfer device comprising at least one charge transfer capacitor, the charge transfer device transferring the charge of the battery cell via the at least one charge transfer capacitor; and An energy storage capacitor, one end of which is connected to the positive terminal of the battery pack through the charge transfer device, and the other end of which is connected to the negative terminal of the battery pack or grounded. The energy storage capacitor and the charge transfer capacitor transfer the charge transferred by the charge transfer device to the battery pack. In which, the battery unit charges the at least one charge transfer capacitor, and the battery pack charges the energy storage capacitor through the charge transfer device to increase the sum of the voltages across the energy storage capacitor and the charge transfer capacitor to a first preset voltage greater than the battery pack voltage, and the energy storage capacitor and the at least one charge transfer capacitor charge the battery pack based on the first preset voltage greater than the battery pack voltage.

2. The active battery balancing device according to claim 1, characterized in that: The charge transfer device is provided in a loop connecting the two ends of the battery unit.

3. The active battery balancing device according to claim 1 or 2, characterized in that: The charge transfer device further comprises a switch group, and the battery pack is charged by controlling the on and off of the switches of the switch group.

4. The active battery balancing device according to claim 3, characterized in that: The switch group includes a chopping switch.

5. The active battery balancing device according to claim 3, characterized in that: The battery equalizer further includes a control and protector, which is used to monitor the voltage and current of the charge transfer capacitor and the energy storage capacitor, and then charge the battery pack by controlling the on and off of the switches of the switch group.

6. A semiconductor chip, characterized in that: A battery active balancing device according to any one of claims 1 to 5 is formed.

7. A battery management system, characterized in that: include: The battery active balancing device according to any one of claims 1 to 5, wherein the battery active balancing device actively balances the battery pack.

8. An electrical device, characterized in that: include: Battery pack; as well as The battery management system according to claim 7, wherein the battery management system actively balances the battery pack based at least on the battery active balancing device.

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