Active equalization circuit and electric device

Abstract

The utility model relates to an active equalization circuit and an electric device. The active equalization circuit comprises a battery pack which comprises a plurality of single batteries connected in series; the first side of the first bidirectional DCDC module is connected with each single battery through a first switch module, and the second side of the first bidirectional DCDC module is connected with the storage battery through a second switch module; the first side of the second bidirectional DCDC module is connected with each single battery through a first switch module, and the second side of the second bidirectional DCDC module is connected with the storage battery through a second switch module; and the control module is used for controlling the first switch module and the second switch module, so that the at least one single battery discharges to the storage battery, or the storage battery discharges to the at least one single battery, or the storage battery discharges to the at least one single battery while the at least one single battery discharges to the storage battery. Therefore, the active equalization circuit transferred by the low-voltage storage battery and the electric device can be charged and discharged at the same time, the performance is reliable, the equalization current is large, the equalization efficiency is high, and no energy is consumed.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to an active balancing circuit and an electric device. Background Art

[0002] A battery pack is a combination of multiple single cells (cells) connected in a certain way to meet higher voltage and capacity requirements while providing a more efficient and safer power source. However, due to the inconsistency of parameters such as voltage, capacity and resistance generated by single cells during the charging and discharging process, the voltages of the single cells in the battery pack may be different, resulting in a decrease in battery pack performance and even shortened battery life.

[0003] Traditional technology uses passive balancing technology to consume excess energy in the battery cell by dissipating heat through resistance, but its balancing current is small and the heat is large, which may not meet the needs of high-performance battery packs in some cases. Utility Model Content

[0004] Based on the above problems, the present application provides an active balancing circuit and device based on low-voltage battery transfer that can perform charging and discharging simultaneously, which has reliable performance, large balancing current, high balancing efficiency and no energy consumption.

[0005] In a first aspect, the present application provides an active equalization circuit, comprising:

[0006] A battery pack, comprising a plurality of single cells connected in series;

[0007] A first bidirectional DCDC module, wherein a first side of the first bidirectional DCDC module is connected to each of the single cells through a first switch module, and a second side of the first bidirectional DCDC module is connected to a storage battery through a second switch module;

[0008] a second bidirectional DCDC module, wherein a first side of the second bidirectional DCDC module is connected to each of the single cells through a first switch module, and a second side of the second bidirectional DCDC module is connected to a storage battery through a second switch module; and

[0009] A control module is connected to the first switch module and the second switch module, and is used to control the first switch module and the second switch module to make at least one of the single cells discharge to the storage battery, or make the storage battery charge at least one of the single cells, or make at least one of the single cells discharge to the storage battery while the storage battery charges at least one of the single cells.

[0010] In one embodiment, the first switch module includes: a first switch unit, a second switch unit, a first bus bar, a second bus bar, a third bus bar and a fourth bus bar;

[0011] The plurality of single cells include a positive electrode and a negative electrode, one of which is electrically connected to the first busbar or the second busbar through the first switch unit or is left vacant, and the other is electrically connected to the third busbar or the fourth busbar through the first switch unit or is left vacant;

[0012] The second switch unit includes a first subunit and a second subunit, the first subunit connects the first bus, the third bus and the first bidirectional DCDC module; the second subunit connects the second bus, the fourth bus and the second bidirectional DCDC module.

[0013] In one embodiment, the plurality of single cells include odd-numbered cells and even-numbered cells arranged alternately, the negative electrode of the odd-numbered cells is connected to the positive electrode of the even-numbered cells, or the positive electrode of the odd-numbered cells is connected to the negative electrode of the even-numbered cells;

[0014] The first switch unit includes a plurality of first switches and a plurality of second switches, wherein a first end of the first switch is connected to the positive electrode of the odd-numbered battery, and a second end of the first switch is connected to the first bus bar or the second bus bar or is left vacant; a first end of the second switch is connected to the positive electrode of the even-numbered battery or the negative electrode of the odd-numbered battery, and a second end of the second switch is connected to the third bus bar or the fourth bus bar or is left vacant.

[0015] In one embodiment, the first switch and / or the second switch is a single-pole double-throw switch.

[0016] In one embodiment, the first subunit includes a third switch and a fourth switch, the first busbar is connected to the first end or the second end of the first bidirectional DCDC module through the third switch; the third busbar is connected to the first end or the second end of the first bidirectional DCDC module through the fourth switch; and / or,

[0017] The second subunit includes a fifth switch and a sixth switch; the second bus is connected to the first end or the second end of the second bidirectional DCDC module through the fifth switch; and the fourth bus is connected to the first end or the second end of the second bidirectional DCDC module through the sixth switch.

[0018] In one embodiment, the second switch module includes a third subunit and a fourth subunit, the first bidirectional DCDC module is electrically connected to the battery through the third subunit, and the second bidirectional DCDC module is electrically connected to the battery through the fourth subunit.

[0019] In one embodiment, the third subunit and / or the fourth subunit comprises a plurality of seventh switches, and the plurality of seventh switches are respectively connected to the positive electrode and the negative electrode of the battery.

[0020] In one embodiment, the first bidirectional DCDC module includes a bidirectional full-bridge DCDC converter or a bidirectional half-bridge DCDC converter; and / or,

[0021] The second bidirectional DCDC module includes a bidirectional full-bridge DCDC converter or a bidirectional half-bridge DCDC converter.

[0022] In one embodiment, the active balancing circuit includes a plurality of battery packs.

[0023] In a second aspect, the present application further provides an electrical device, wherein the electrical device comprises the active balancing circuit.

[0024] In the above-mentioned active balancing circuit and power-consuming device, the first bidirectional DCDC module and the second bidirectional DCDC module are both connected to each single cell through the first switch module, and connected to the storage battery through the second switch module. The control module can control the first bidirectional DCDC module and the second bidirectional DCDC module to connect to the target single cell by controlling the first switch module and the second switch module. The control module controls the first switch module and the second switch module to discharge the target single cell to the storage battery, or to charge the target battery through the storage battery. When some single cells are connected to the first bidirectional DCDC module and some single cells are connected to the second bidirectional DCDC module, different single cells in the battery pack are discharged and charged at the same time. In this way, the problem of battery cell imbalance when the voltage of some single cells in the battery pack is higher than the average voltage and the voltage of some single cells is lower than the average voltage is solved. The active balancing circuit and the power-consuming device transferred by the low-voltage storage battery can be charged and discharged at the same time, and its performance is reliable, the balancing current is large, the balancing efficiency is high, and there is no energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 FIG. 4 is a structural block diagram of an active equalization circuit in an embodiment.

[0027] Figure 2 FIG. 4 is a circuit diagram of an active equalization circuit in one embodiment.

[0028] Figure 3 FIG. 1 is a schematic diagram of the connection between a battery pack and a bus bar in an embodiment.

[0029] Figure 4 FIG. 4 is a circuit diagram of a bidirectional full-bridge DCDC module in one embodiment.

[0030] Figure 5 FIG. 4 is a circuit diagram of a bidirectional half-bridge DCDC module in one embodiment.

[0031] Description of reference numerals:

[0032] 10. Battery pack; 11. Single battery; 20. First switch module; 21. First switch unit; 211. First switch; 212. Second switch; 22. Second switch unit; 221. First subunit; 222. Second subunit; 231. Third switch; 232. Fourth switch; 233. Fifth switch; 234. Sixth switch; 24. First bus; 25. Second bus; 26. Third bus; 27. Fourth bus; 30. First bidirectional DCDC module; 40. Second bidirectional DCDC module; 50. Second switch module; 51. Third subunit; 52. Fourth subunit; 53. Seventh switch; 60. Battery; 70. Control module. DETAILED DESCRIPTION

[0033] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0035] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0036] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0037] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0038] See also Figure 1 , Figure 1 The structure block diagram of an active balancing circuit in an embodiment is shown. The active balancing circuit includes a battery pack 10, a first bidirectional DCDC module 30, a second bidirectional DCDC module 40, a control module 70 and a storage battery 60. The battery pack 10 includes a plurality of single cells 11 connected in series, a first bidirectional DCDC module 30, a first side of which is connected to each single cell 11 through a first switch module 20, and a second side of which is connected to the storage battery 60 through a second switch module 50; a second bidirectional DCDC module 40, a first side of which is connected to each single cell 11 through a first switch module 20, and a second side of which is connected to the storage battery 60 through a second switch module 50; and a control module 70, which is connected to the first switch module 20 and the second switch module 50, and is used to control the first switch module 20 and the second switch module 50, so that at least one single cell 11 discharges to the storage battery 60, or the storage battery 60 charges at least one single cell 11, or at least one single cell 11 discharges to the storage battery 60 while the storage battery 60 charges at least one single cell 11.

[0039] Exemplarily, the number of battery packs 10 may be one or more than two, and the active balancing circuit may include multiple battery packs 10, each of which may include multiple single cells 11. Due to the inconsistency of parameters such as voltage, capacity, and resistance generated by the single cells 11 during the charging and discharging process, this may cause the performance of the battery pack to deteriorate, or even shorten the battery life. To this end, it is necessary to discharge the single cells 11 with high power and charge the single cells 11 with low power, so that the voltage difference of each single cell 11 reaches a set value or remains within a certain range.

[0040] Exemplarily, the battery 60 can be a 12V or 24V battery, such as a lead-acid battery, a sodium-ion battery, a lithium-ion battery, etc. The first bidirectional DCDC module 30 and the second bidirectional DCDC module 40 are both connected to the battery pack 10 and the battery 60, and can perform voltage conversion between the battery pack 10 and the battery 60. Exemplarily, the first bidirectional DCDC module 30 and / or the second bidirectional DCDC module 40 can be an isolated bidirectional DC-DC, and the two DC-DC modules can simultaneously discharge the single cell 11 in a balanced manner, or simultaneously charge the single cell 11 in a balanced manner, or one DC-DC module charges the single cell 11 in a balanced manner, and the other DC-DC module discharges the single cell in a balanced manner. And the forward and reverse output voltage adjustment ratio of the first bidirectional DCDC module 30 and / or the second bidirectional DCDC module 40 can be adjusted according to actual needs. For example, when the voltage of the battery cell is 3.2V, three battery cells are connected in series to the battery, and the voltage of the battery 60 is 14V, it can be transformed through the DCDC module, and the voltage conversion ratio is 9.6:14 at this time. The control module 70 is used to control the first switch module 20 and the second switch module 50, so as to control the target single battery 11 in the battery pack 10 to be connected to the first bidirectional DCDC module 30 or the second bidirectional DCDC module 40. Furthermore, the voltage conversion ratio and the charge and discharge current direction of the first bidirectional DCDC module and the second bidirectional DCDC module can also be controlled by the control module 70.

[0041] Exemplarily, when the voltage of the target single cell 11 is too high and needs to be discharged, the control module 70 controls the first switch module 20 and the second switch module 50 to connect the target single cell 11 with the first bidirectional DCDC module 30 and the battery 60 , and the target single cell 11 discharges to the battery 60 .

[0042] Exemplarily, when the voltage of the target single cell 11 is too low and needs to be charged, the control module 70 controls the first switch module 20 and the second switch module 50 to connect the target single cell 11 with the second bidirectional DCDC module 40 and the battery 60 , and the battery 60 charges the target single cell 11 .

[0043] Exemplarily, when some single cells 11 need to be discharged and some single cells 11 need to be charged, the control module 70 controls the first switch module 20 and the second switch module 50 to electrically connect the first bidirectional DCDC module 30 to the single cells 11 that need to be discharged, and discharge to the battery 60; and also electrically connect the second bidirectional DCDC module 40 to the battery cells that need to be charged, and the battery 60 charges them.

[0044] It can be understood that the connection method between the first bidirectional DCDC module 30 and the second bidirectional DCDC module 40 and the battery in this embodiment is only an example. In other possible implementations, the battery 60 can also charge the single cell 11 through the first bidirectional DCDC module 30, and the single cell 11 can also discharge to the battery 60 through the second bidirectional DCDC module 40.

[0045] In the above active balancing circuit, the first bidirectional DCDC module 30 and the second bidirectional DCDC module 40 are both connected to each single cell 11 through the first switch module 20, and connected to the storage battery 60 through the second switch module 50. The control module 70 can control the first bidirectional DCDC module 30 and the second bidirectional DCDC module 40 to connect to the target single cell 11 by controlling the first switch module 20 and the second switch module 50. The control module 70 controls the first switch module 20 and the second switch module 50, so that the target single cell 11 discharges to the storage battery 60, or charges the target single cell 11 through the storage battery 60. When some single cells 11 are connected to the first bidirectional DCDC module 30 and some single cells 11 are connected to the second bidirectional DCDC module 40, different single cells 11 in the battery pack 10 are discharged and charged at the same time. In this way, the problem of battery cell imbalance when the voltage of some single cells 11 in the battery pack 10 is higher than the average voltage and the voltage of some single cells 11 is lower than the average voltage is solved, and the active balancing circuit and the power-consuming device transferred by the low-voltage battery can be charged and discharged at the same time, with reliable performance, large balancing current, high balancing efficiency and no energy consumption.

[0046] For example, a battery pack 10 or a battery cluster can be formed by connecting multiple single cells 11 in series or in series and parallel according to the type and voltage requirements. Each battery pack 10 is controlled by an AFE (Analog Front End) sampling chip, which is responsible for collecting the voltage and temperature of each single cell 11 in the battery pack 10 and controlling the balancing circuit.

[0047] At the same time, the control module 70 may include a main control chip, such as an MCU (Microcontroller Unit) or a single-chip microcomputer, which is responsible for calculating the SOC (State of Charge) / SOH (State of Health) and balancing capacity of each battery cell according to the AFE sampling information, controlling the opening and closing of each balancing switch, and controlling the forward and reverse output modes, voltage adjustment ratio, etc. of the first bidirectional DCDC module 30 and the second bidirectional DCDC module 40.

[0048] See also Figure 2 , Figure 2A circuit diagram of an active balancing circuit in one embodiment is shown. In some embodiments, a plurality of single cells 11 are connected in series, that is, the positive electrode of one single cell 11 is connected to the negative electrode of another adjacent single cell 11. Specifically, the first switch module 20 includes: a first switch unit 21, a second switch unit 22, a first busbar 24, a second busbar 25, a third busbar 26 and a fourth busbar 27; a plurality of single cells 11 include positive and negative electrodes, one of which is electrically connected to the first busbar 24 or the second busbar 25 through the first switch unit 21 or is vacant, and the other is electrically connected to the third busbar 26 or the fourth busbar 27 through the first switch unit 21 or is vacant; the second switch unit 22 includes a first subunit 221 and a second subunit 222, the first subunit 221 connects the first busbar 24, the third busbar 26 and the first bidirectional DCDC module 30; the second subunit 222 connects the second busbar 25, the fourth busbar 27 and the second bidirectional DCDC module 40. The control module 70 controls the connection between the first bidirectional DCDC module 30 and the second bidirectional DCDC module 40 and the single battery 11 by controlling the first switch unit 21 and the second switch unit 22 .

[0049] Exemplarily, the positive electrode of the single battery 11 is electrically connected to the first busbar 24 or the second busbar 25 through the first switch unit 21 or is left vacant, and the negative electrode of the single battery 11 is electrically connected to the third busbar 26 or the fourth busbar 27 through the first switch unit 21 or is left vacant. In a feasible implementation, the positive electrode and the negative electrode of each single battery 11 are provided with a circuit and a switch connected to the busbar, respectively controlling the connected positive electrode and negative electrode, that is, each battery cell is controlled separately.

[0050] In this way, the first switch unit 21 can control any single cell 11 to be connected to the first bidirectional DCDC module 30 or the second bidirectional DCDC module 40 , so that the single cell 11 discharges to the storage battery 60 , or the storage battery 60 charges the single cell 11 .

[0051] In some embodiments, the plurality of single cells 11 include odd-numbered cells and even-numbered cells that are alternately arranged, and the negative electrode of the odd-numbered cell is connected to the positive electrode of the even-numbered cell, or the positive electrode of the odd-numbered cell is connected to the negative electrode of the even-numbered cell. Exemplarily, the odd-numbered cell refers to the cell located at the odd position after all the cells of the battery pack 10 are numbered in sequence, and the even-numbered cell refers to the cell located at the even position. For example, if the battery pack 10 includes 6 single cells 11, which are numbered Cell1, Cell2, Cell3, Cell4, Cell5 and Cell6 in sequence, the odd-numbered cells are Cell1, Cell3 and Cell5, and the even-numbered cells are Cell2, Cell4 and Cell6. Exemplarily, the negative electrode of the odd-numbered cell is connected to the positive electrode of the even-numbered cell, or the positive electrode of the odd-numbered cell is connected to the negative electrode of the even-numbered cell, so that each single cell 11 is connected in series. When the battery pack includes an odd number of single cells 11 , the last single cell 11 is an odd number of cells; when the battery pack includes an even number of single cells 11 , the last single cell 11 is an even number of cells.

[0052] See also Figure 3 , Figure 3 A schematic diagram showing a battery pack 10 connected to a first busbar 24, a second busbar 25, a third busbar 26 and a fourth busbar 27 through a first switch module 20 in an embodiment is shown. The first switch unit 21 includes a plurality of first switches 211 and a plurality of second switches 212, wherein a first end of the first switch 211 is connected to the positive electrode of an odd-numbered battery, and a second end of the first switch 211 is connected to the first busbar 24 or the second busbar 25 or is left vacant; a first end of the second switch 212 is connected to the positive electrode of an even-numbered battery or the negative electrode of an odd-numbered battery, and a second end of the second switch 212 is connected to the third busbar 26 or the fourth busbar 27 or is left vacant.

[0053] It should be noted that when the battery pack includes an odd number of single cells 11, the first end of the second switch 212 is connected to the positive electrode of the even number of cells and the negative electrode of the last odd number of cells; when the battery pack includes an even number of single cells 11, the first end of the second switch 212 is connected to the positive electrode of the even number of cells.

[0054] Optionally, the first switch 211 and / or the second switch 212 is a single-pole double-throw switch, so that it can be selectively electrically connected to the busbar. It is understandable that Figure 2 The connection relationship between the first switch 211 and the second switch 212 is only an example. In other embodiments, the second switch 212 may be the first switch, and the second switch 212 and the first switch 211 are alternated. In other possible implementations, the wires led out of one pole of each single cell correspond to two first switches 211 or two second switches 212 to selectively connect to the busbar.

[0055] Thus, except for the first and last single cells 11, the first switch 211 simultaneously connects the positive electrodes of the odd-numbered cells and the negative electrodes of the even-numbered cells, and the second switch 212 simultaneously connects the negative electrodes of the odd-numbered cells and the positive electrodes of the even-numbered cells.

[0056] The second switch unit 22 includes a first subunit 221 and a second subunit 222. The first subunit 221 connects the first bus 24, the third bus 26 and the first bidirectional DCDC module 30; the second subunit 222 connects the second bus 25, the fourth bus 27 and the second bidirectional DCDC module 40. In this way, the control module 70 can control the conduction of the first bidirectional DCDC module 30 through the first subunit 221, and control the conduction of the second bidirectional DCDC module 40 through the second subunit 222.

[0057] Exemplarily, when the first switch connecting the negative electrode of Cell2 and the positive electrode of Cell3 is connected to the first bus 24, and the second switch connecting the negative electrode of Cell3 and the positive electrode of Cell4 is connected to the third bus 26, Cell3 is turned on with the first bidirectional DCDC module 30. Exemplarily, when the first switch connecting the positive electrode of Cell1 is connected to the second bus 25, and the second switch connecting the negative electrode of Cell3 and the positive electrode of Cell4 is connected to the fourth bus 27, Cell1, Cell2 and Cell3 are turned on with the second bidirectional DCDC module 40 at the same time. Exemplarily, when the first switch connected to the positive electrode of Cell1 is connected to the first bus 24, the second switch connected to the negative electrode of Cell1 and the positive electrode of Cell2 is connected to the third bus 26, and the first switch connected to the negative electrode of Cell2 and the positive electrode of Cell3 is connected to the second bus 25, and the second switch connected to the negative electrode of Cell3 and the positive electrode of Cell4 is connected to the fourth bus 27, Cell1 is turned on to the first bidirectional DCDC module 30, and Cell3 is turned on to the second bidirectional DCDC module 40.

[0058] Through the first switch module 20, the control module 70 can control the first switch unit 21 and the second switch unit 22 to control whether the single battery 11 in the battery pack 10 is connected to the first bidirectional DCDC module 30 or the second bidirectional DCDC module 40, thereby controlling the discharge or charge of the single battery 11, or simultaneously controlling the charging of some single batteries 11 in the battery pack 10 and the discharge of some single batteries 11. Figure 2In some embodiments, the first subunit 221 includes a third switch 231 and a fourth switch 232. The first busbar 24 is connected to the first end or the second end of the first bidirectional DCDC module 30 through the third switch 231; the third busbar 26 is connected to the first end or the second end of the first bidirectional DCDC module through the fourth switch 232. In this way, the first busbar 24 can be switched to be electrically connected to the first end or the second end of the first bidirectional DCDC module 30 through the third switch 231, and the third busbar 26 can be switched to be connected to the first end or the second end of the first bidirectional DCDC module 30 through the fourth switch. Further, the first busbar 24 can be controlled to be connected to the first end of the first bidirectional DCDC module 30, and the third busbar 26 can be connected to the second end of the first bidirectional DCDC module 30, or the first busbar 24 can be controlled to be connected to the second end of the first bidirectional DCDC module 30, and the third busbar 26 can be connected to the first end of the first bidirectional DCDC module 30.

[0059] and / or; in some embodiments, the second subunit 222 includes a fifth switch 233 and a sixth switch 234; the second bus 25 is respectively connected to the first end or the second end of the second bidirectional DCDC module 40 through the fifth switch 233; the fourth bus 27 is respectively connected to the first end or the second end of the second bidirectional DCDC module 40 through the sixth switch 234. Further, the second bus 25 can be controlled to be connected to the first end of the second bidirectional DCDC module 40, and the fourth bus 27 can be connected to the second end of the second bidirectional DCDC module 40, or the second bus 25 can be controlled to be connected to the second end of the second bidirectional DCDC module 40, and the fourth bus 27 can be connected to the first end of the second bidirectional DCDC module 40.

[0060] Furthermore, the third switch 231 is switched according to the polarity of the series-connected single cells connected to the first busbar 24 and the third busbar 26. The positive electrode of the series-connected single cells is connected to the positive electrode of the bidirectional DCDC module, and the negative electrode of the series-connected single cells is connected to the negative electrode of the bidirectional DCDC module.

[0061] The following is an example in which the first end of the first bidirectional DCDC module 30 is the positive electrode and the second end is the negative electrode. When the first busbar 24 is connected to the positive electrode of Cell1 and the third busbar 26 is connected to the negative electrode of Cell5, the first busbar 24 is connected to the positive electrode of the first end of the first bidirectional DCDC module 30 by controlling the third switch 231, and the third busbar 26 is connected to the negative electrode of the second end of the first bidirectional DCDC module 30 by controlling the fourth switch 232. Thus, the positive electrodes of Cell1 to Cell5 are connected to the positive electrode of the first bidirectional DCDC module 30 through the first busbar 24, and the negative electrodes of Cell1 to Cell5 are connected to the negative electrode of the first bidirectional DCDC module 30 through the third busbar 26.

[0062] When the first busbar 24 is connected to the negative electrode of Cell6 and the third busbar 26 is connected to the positive electrode of Cell4, the first busbar 24 is connected to the negative electrode of the second end of the first bidirectional DCDC module 30 by controlling the third switch 231, and the third busbar 26 is connected to the positive electrode of the first end of the first bidirectional DCDC module 30 by controlling the fourth switch 232.

[0063] The positive electrodes of Cell4 - Cell6 are connected to the positive electrode of the first bidirectional DCDC module 30 through the third busbar 26 , and the negative electrodes of Cell4 - Cell6 are connected to the negative electrode of the first bidirectional DCDC module 30 through the first busbar 24 .

[0064] Among them, two third switches 231 can be set to connect the first bus 24 and the first end or the second end of the first bidirectional DCDC module 30 respectively. The third switch 231 can also be set to a single-pole double-throw switch to connect the first bus 24 and the first end or the second end of the first bidirectional DCDC module 30 respectively.

[0065] The first end and the second end of the first bidirectional DCDC module 30 are connected to the positive electrode and the negative electrode of the single cell 11 respectively, and the third end and the fourth end of the first bidirectional DCDC module 30 are connected to the second switch module 50, and then connected to the battery 60, so that the voltage is regulated between the single cell 11 and the battery 60. Similar to the first bidirectional DCDC module 30, the second bidirectional DCDC module 40 can also regulate the voltage between the single cell 11 and the battery 60.

[0066] By controlling the switching of the third switch 231, the fourth switch 232, the fifth switch 233 and the sixth switch 234 through the first subunit 221 and the second subunit 222, the single cell 11 connected to the storage battery 60 can be controlled to discharge or charge the single cell 11. One side of the first bidirectional DCDC module 30 and the second bidirectional DCDC module 40 is connected to the single cell 11 that needs to be balanced through a multi-stage switch, and each DCDC module can support the balanced charging or balanced discharging of any number of adjacent single cells 11 at the same time; the combination of two DCDC modules can meet the balanced charging and discharging requirements of multiple different combinations of single cells 11, and the balancing efficiency is greatly improved.

[0067] In some embodiments, the second switch module 50 includes a third subunit 51 and a fourth subunit 52, the first bidirectional DCDC module 30 is electrically connected to the battery 60 through the third subunit 51, and the second bidirectional DCDC module 40 is electrically connected to the battery 60 through the fourth subunit 52. In this way, the control module 70 can control the conduction between the first bidirectional DCDC module 30 and the battery 60 through the third subunit 51, and control the conduction between the second bidirectional DCDC module 40 and the battery 60 through the fourth subunit 52.

[0068] In some feasible implementations, the third subunit 51 and / or the fourth subunit 52 include a plurality of seventh switches 53, and the plurality of seventh switches 53 are respectively connected to the positive electrode and the negative electrode of the battery 60. Exemplarily, the first bidirectional DCDC module 30 is respectively connected to the positive electrode and the negative electrode of the battery 60 through two seventh switches 53, such as the third end of the first bidirectional DCDC module 30 is electrically connected to the positive electrode of the battery 60 through the seventh switch 53, and the fourth end of the first bidirectional DCDC module 30 is electrically connected to the negative electrode of the battery 60 through another seventh switch 53. Exemplarily, the third end of the second bidirectional DCDC module 40 is electrically connected to the positive electrode of the battery 60 through another seventh switch 53, and the fourth end of the second bidirectional DCDC module 40 is electrically connected to the negative electrode of the battery 60 through another seventh switch 53.

[0069] For example, see Figure 2 and Figure 3 The number of cells 11 in the battery pack 10 is variable. The first bidirectional DCDC module 30 can be used to enable the storage battery 60 to charge the cell 11, and can also be used to enable the cell 11 to discharge to the storage battery 60. Similarly, the second bidirectional DCDC module 30 can also be used to enable the storage battery 60 to charge the cell 11, and can also be used to enable the cell 11 to discharge to the storage battery 60.

[0070] Exemplarily, when a plurality of single cells 11 connected in series discharge to the storage battery 60 through the first bidirectional DCDC module 30, the number of single cells 11 connected in series should be an odd number. Taking Cell1 to Cell5 connected in series as an example, the control module 70 controls the first switch 211 of the positive electrode of Cell1 to be electrically connected to the first bus 24, controls the second switch 212 of the negative electrode of Cell5 to be electrically connected to the third bus 26, controls the third switch 231 to connect the first bus 24 to the first end of the first bidirectional DCDC module 30, and controls the fourth switch 232 to connect the third bus 26 to the second end of the first bidirectional DCDC module 30, so that the Cell1 to Cell5 connected in series are connected to the first bidirectional DCDC module.

[0071] For example, when it is necessary to balance discharge or balance charge an even number of consecutive single cells 11 connected in series, the even number of cells can be split into odd number of cells for balancing. For example, when balancing an even number of 6 consecutive single cells 11, they can be split into an odd number of 3 and 3 consecutive single cells 11 for balancing in sequence, or split into an odd number of 5 and 1 for balancing in sequence.

[0072] See also Figure 4 , Figure 4 A circuit diagram of a bidirectional full-bridge DCDC in one embodiment is shown. Figure 5A circuit diagram of a bidirectional half-bridge DCDC module in one embodiment is shown. In some embodiments, the first bidirectional DCDC module 30 and / or the second bidirectional DCDC module 40 include a half-bridge DCDC converter. When the DCDC module outputs in the forward direction, the single cell 11 connected to it is discharged evenly, and the storage battery 60 on the right is in a charging state, and the transformation coefficient of the DCDC module can be adjusted in real time according to the number of connected series single cells 11 and the voltage of the storage battery 60. When the DCDC module outputs in the reverse direction, the single cell 11 connected to it on the left is charged evenly, and the storage battery 60 on the right is in a discharging stage.

[0073] For example, the first bidirectional DCDC module 30 and / or the second bidirectional DCDC module 40 may be Figure 4 The bidirectional full-bridge DCDC module shown, the first bidirectional DCDC module 30 and / or the second bidirectional DCDC module 40 include: a first switch tube D1, a second switch tube D2, a third switch tube D3, a fourth switch tube D4, a fifth switch tube D5, a sixth switch tube D6, a first inductor L1, a second inductor L2, a third inductor L3, a transformer unit M and a capacitor C3.

[0074] The first end of the first switch tube D1 and the first end of the third switch tube D3 serve as the first end of the DCDC module and are electrically connected to the first switch module 20. The second end of the first switch tube D1 is electrically connected to the first end of the second switch tube D2, and the second end of the second switch tube D2 and the second end of the fourth switch tube serve as the second end of the DCDC module and are electrically connected to the first switch module 20. The second end of the third switch tube D3 is electrically connected to the first end of the fourth switch tube D4, and the second end of the third switch tube D3 is connected to the first end of the first inductor L1, the second end of the first inductor L1 is connected to the first end of the transformer unit M, and the second end of the first switch tube D1 is connected to the second end of the transformer unit M.

[0075] The third end of the transformer unit M is electrically connected to the first end of the fifth switch tube D5, the second end of the fifth switch tube D5 is electrically connected to the first end of the sixth switch tube D6, and the fourth end of the transformer unit M is electrically connected to the second end of the sixth switch tube D6. The first end of the fifth switch tube D5 is also electrically connected to the first end of the second inductor L2, the second end of the second inductor L2 is electrically connected to the second end of the third inductor L3, and the second end of the sixth switch tube D6 is also electrically connected to the first end of the third inductor L3. The second end of the second inductor L2 is also electrically connected to the first end of the capacitor C3, and is electrically connected to the second switch module 50 as the third end of the DCDC module. The second end of the fifth switch tube D5 is electrically connected to the second end of the capacitor C3, and is electrically connected to the second switch module 50 as the fourth end of the DCDC module.

[0076] For example, the first bidirectional DCDC module 30 and / or the second bidirectional DCDC module 40 may be Figure 5 Compared with the bidirectional full-bridge DCDC module, the bidirectional half-bridge DCDC module shown in the figure replaces the first switch tube D1 with a capacitor C1 and the second switch tube D2 with a capacitor C2.

[0077] In some embodiments, the control module 70 is used to control the single cell to discharge to the storage battery 60, or to make the storage battery 60 charge the single cell 11, according to the average voltage of the battery pack 10 and the voltage value of the single cell. Exemplarily, when the voltage value of the single cell 11 is higher than the average voltage, the control module 70 controls the first switch module 20 and the second switch module 50 to connect the single cell 11 with the storage battery 60 and discharge the storage battery 60. Exemplarily, when the voltage value of the single cell 11 is lower than the average voltage, the control module 70 controls the first switch module 20 and the second switch module 50 to connect the single cell 11 with the storage battery 60 and make the storage battery 60 charge the single cell 11.

[0078] The embodiment of the present application also provides an electrical device, which includes at least one active balancing circuit described in the above embodiment. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, etc. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, and an electric airplane toy. It is understandable that the battery can be used to connect to the motor on the electrical device. The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] In the description of this specification, the descriptions with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc., mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0080] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0081] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An active equalization circuit, characterized in that: include: A battery pack, comprising a plurality of single cells connected in series; A first bidirectional DCDC module, wherein a first side of the first bidirectional DCDC module is connected to each of the single cells through a first switch module, and a second side of the first bidirectional DCDC module is connected to a storage battery through a second switch module; A second bidirectional DCDC module, wherein a first side of the second bidirectional DCDC module is connected to each of the single cells through a first switch module, and a second side of the second bidirectional DCDC module is connected to a storage battery through a second switch module; as well as A control module is connected to the first switch module and the second switch module, and is used to control the first switch module and the second switch module to make at least one of the single cells discharge to the storage battery, or make the storage battery charge at least one of the single cells, or make at least one of the single cells discharge to the storage battery while the storage battery charges at least one of the single cells.

2. The active equalization circuit according to claim 1, characterized in that: The first switch module includes: a first switch unit, a second switch unit, a first bus bar, a second bus bar, a third bus bar and a fourth bus bar; The plurality of single cells include a positive electrode and a negative electrode, one of which is electrically connected to the first busbar or the second busbar through the first switch unit or is left vacant, and the other is electrically connected to the third busbar or the fourth busbar through the first switch unit or is left vacant; The second switch unit includes a first subunit and a second subunit, the first subunit connects the first bus, the third bus and the first bidirectional DCDC module; the second subunit connects the second bus, the fourth bus and the second bidirectional DCDC module.

3. The active equalization circuit according to claim 2, characterized in that: The plurality of single cells include odd-numbered cells and even-numbered cells that are alternately arranged, the negative electrodes of the odd-numbered cells are connected to the positive electrodes of the even-numbered cells, or the positive electrodes of the odd-numbered cells are connected to the negative electrodes of the even-numbered cells; The first switch unit includes a plurality of first switches and a plurality of second switches, wherein a first end of the first switch is connected to the positive electrode of the odd-numbered battery, and a second end of the first switch is connected to the first bus bar or the second bus bar or is left vacant; a first end of the second switch is connected to the positive electrode of the even-numbered battery or the negative electrode of the odd-numbered battery, and a second end of the second switch is connected to the third bus bar or the fourth bus bar or is left vacant.

4. The active equalization circuit according to claim 3, characterized in that: The first switch and / or the second switch is a single-pole double-throw switch.

5. The active equalization circuit according to claim 2, characterized in that: The first subunit includes a third switch and a fourth switch, the first busbar is connected to the first end or the second end of the first bidirectional DCDC module through the third switch; the third busbar is connected to the first end or the second end of the first bidirectional DCDC module through the fourth switch; and / or, The second subunit includes a fifth switch and a sixth switch; the second bus is connected to the first end or the second end of the second bidirectional DCDC module through the fifth switch; and the fourth bus is connected to the first end or the second end of the second bidirectional DCDC module through the sixth switch.

6. The active equalization circuit according to claim 1, characterized in that: The second switch module includes a third subunit and a fourth subunit, the first bidirectional DCDC module is electrically connected to the battery through the third subunit, and the second bidirectional DCDC module is electrically connected to the battery through the fourth subunit.

7. The active equalization circuit according to claim 6, characterized in that: The third subunit and / or the fourth subunit comprises a plurality of seventh switches, and the plurality of seventh switches are respectively connected to the positive electrode and the negative electrode of the battery.

8. The active equalization circuit according to claim 1, characterized in that: The first bidirectional DCDC module includes a bidirectional full-bridge DCDC converter or a bidirectional half-bridge DCDC converter; and / or, The second bidirectional DCDC module includes a bidirectional full-bridge DCDC converter or a bidirectional half-bridge DCDC converter.

9. The active equalization circuit according to claim 1, characterized in that: The active balancing circuit includes a plurality of battery packs.

10. An electrical device, characterized in that: The electrical device comprises the active balancing circuit according to any one of claims 1-9.

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