Energy storage battery equalization circuit and method thereof, energy storage battery equalizer

Abstract

The present application relates to an energy storage battery balancing circuit, method and energy storage battery equalizer. The energy storage battery balancing circuit includes: a plurality of first bidirectional balancing circuits and a plurality of second bidirectional balancing circuits. The first bidirectional balancing circuit is connected to a battery module in correspondence, and is configured to: balance the voltage of a first battery cell and the voltage of a second battery cell in the battery module. The second bidirectional balancing circuit is connected to any two adjacent battery modules in correspondence, and is configured to: balance the voltage of a second battery cell in the first battery module of the any two adjacent battery modules, and the voltage of a first battery cell in the second battery module of the any two adjacent battery modules. The present application is used to improve the balancing speed, efficiency and battery utilization, and at the same time realize the miniaturization and modular expansion of the energy storage battery balancing circuit.

Description

Technical Field

[0001] The present application relates to the field of energy storage battery balancing control, and in particular to an energy storage battery balancing circuit and method thereof, and an energy storage battery equalizer. Background Art

[0002] In recent years, with the massive promotion of the new energy industry, the utilization of lithium batteries has been increasing. When using energy storage batteries, a single battery cell usually cannot meet the needs of practical applications. Therefore, in order to obtain higher voltage and power, multiple battery cells are generally used in series or in parallel. However, due to the characteristics of deep charging and discharging of the energy storage system, after multiple charges and discharges, the consistency of the cell capacity within the battery cluster will have a serious impact on the available capacity of the energy storage system. If effective measures are not taken, the reliability of the entire energy storage battery system will be greatly reduced, its service life will be shortened, and it may even cause serious safety hazards. Therefore, the development of a safe, efficient and reliable battery balancing control system is of great significance to improving the inconsistency between battery cells.

[0003] However, existing battery balancing technologies are mainly divided into passive balancing and active balancing. Passive balancing has large balancing energy loss and low balancing efficiency, while active balancing uses more components and has the problems of high cost and unsatisfactory long-distance balancing speed and balancing efficiency. Summary of the invention

[0004] Based on this, it is necessary to provide an energy storage battery balancing circuit and method thereof, and an energy storage battery equalizer, which are used to ensure that the voltages of each battery cell tend to be consistent more quickly and effectively, thereby eliminating the voltage differences between different battery cells, and easily improving the balancing speed, balancing efficiency and battery energy utilization, as well as reducing costs and circuit size, so as to achieve miniaturization and modular expansion of the energy storage battery balancing circuit and the energy storage battery equalizer.

[0005] A storage battery balancing circuit is applied to a plurality of first battery cells and a plurality of second battery cells alternately connected in series, wherein each first battery cell and the second battery cell connected in series therewith constitute a battery module. The storage battery balancing circuit comprises: a plurality of first bidirectional balancing circuits and a plurality of second bidirectional balancing circuits. The first bidirectional balancing circuit is connected to the battery module in correspondence, and is configured to: balance the voltage of the first battery cell and the voltage of the second battery cell in the battery module. The second bidirectional balancing circuit is connected to any two adjacent battery modules in correspondence, and is configured to: balance the voltage of the second battery cell in the first battery module of the any two adjacent battery modules, and the voltage of the first battery cell in the second battery module of the any two adjacent battery modules.

[0006] In some embodiments of the present disclosure, the energy storage battery balancing circuit further includes: a first switch device connected to each first battery cell, and a second switch device connected to each second battery cell. The first bidirectional balancing circuit and the second bidirectional balancing circuit share the first switch device connected to the first battery cell, and share the second switch device connected to the second battery cell.

[0007] In some embodiments of the present disclosure, the negative electrode of the first battery cell is connected to the positive electrode of the second battery cell, and the negative electrode of the second battery cell is connected to the positive electrode of the first battery cell in the adjacent battery module. The first switching device and the second switching device both have a first end and a second end. The first bidirectional balancing circuit also includes: a first energy storage capacitor and an energy storage inductor. The first energy storage capacitor has a first end and a second end; the first end of the first energy storage capacitor is connected to the positive electrode of the first battery cell and the first end of the first switching device, and the second end of the first energy storage capacitor is connected to the negative electrode of the second battery cell and the second end of the second switching device. The energy storage inductor has a first end and a second end; the first end of the energy storage inductor is connected to the negative electrode of the first battery cell and the positive electrode of the second battery cell, and the second end of the energy storage inductor is connected to the second end of the first switching device and the first end of the second switching device.

[0008] In some embodiments of the present disclosure, the second bidirectional balancing circuit further includes: a second energy storage capacitor. The second energy storage capacitor has a first end and a second end; the first end of the second energy storage capacitor is connected to the second end of the energy storage inductor corresponding to the first battery module of any two adjacent battery modules and the first end of the second switch device corresponding to the first battery module; the second end of the second energy storage capacitor is connected to the second end of the energy storage inductor corresponding to the second battery module of any two adjacent battery modules and the second end of the first switch device corresponding to the second battery module.

[0009] In some embodiments of the present disclosure, the first end of the first switching device and the first end of the second switching device are both drains of the corresponding switching devices, and the second end of the first switching device and the second end of the second switching device are both sources of the corresponding switching devices.

[0010] In some embodiments of the present disclosure, the first switch device and the second switch device each further have a control terminal. The energy storage battery balancing circuit further includes: a control module. The control module is connected to the control terminals of each first switch device and each second switch device, and is configured to: output a first control signal to each first switch device, and output a second control signal to each second switch device, so as to respectively control the conduction and shutdown of the corresponding switch device; wherein the first control signal and the second control signal are complementary control signals.

[0011] Some embodiments of the present disclosure further provide an energy storage battery equalizer, comprising the energy storage battery equalization circuit as described in any of the above embodiments.

[0012] Some embodiments of the present disclosure also provide an energy storage battery balancing method, which is applied to a plurality of first battery cells and a plurality of second battery cells alternately connected in series, wherein each first battery cell and the second battery cell connected in series therewith constitute a battery module. The energy storage battery balancing method comprises: controlling a first bidirectional balancing circuit to balance the voltage of a first battery cell and the voltage of a second battery cell in a battery module; controlling a second bidirectional balancing circuit to balance the voltage of a second battery cell in a first battery module of any two adjacent battery modules and the voltage of a first battery cell in a second battery module of any two adjacent battery modules.

[0013] In some embodiments of the present disclosure, the first bidirectional balancing circuit and the second bidirectional balancing circuit share a first switching device connected to the corresponding first battery unit and a second switching device connected to the corresponding second battery unit to synchronously perform voltage balancing.

[0014] In some embodiments of the present disclosure, controlling the first bidirectional balancing circuit and the second bidirectional balancing circuit to perform voltage balancing includes: sending a first control signal to each first switching device, and outputting a second control signal to each second switching device to respectively control the on and off of the corresponding switching device; wherein the first control signal and the second control signal are complementary control signals.

[0015] In the energy storage battery equalization circuit and method, and energy storage battery equalizer, a first bidirectional equalization circuit and a second bidirectional equalization circuit are respectively provided for each battery module, and the first bidirectional equalization circuit can be used to equalize the voltage of the first battery cell and the voltage of the second battery cell in the same battery module, and the second bidirectional equalization circuit can be used to equalize the voltage of the second battery cell in the first battery module of any two adjacent battery modules and the voltage of the first battery cell in the second battery module of any two adjacent battery modules. Thus, it is possible to more quickly and effectively ensure that the voltages of the various battery cells tend to be consistent, so as to eliminate the differences in voltages between different battery cells, and it is easy to improve the equalization speed, the equalization efficiency, and the utilization rate of battery energy.

[0016] In addition, in some embodiments, the first bidirectional balancing circuit and the second bidirectional balancing circuit can share the first switch device connected to the corresponding first battery unit and share the second switch device connected to the corresponding second battery unit for voltage balancing; that is, the first bidirectional balancing circuit and the second bidirectional balancing circuit can share the switch device. In this way, the number of components used in the energy storage battery balancing circuit is effectively reduced, and it is also beneficial to reduce the energy transfer loss between battery units, thereby reducing costs and reducing the circuit volume, so as to achieve miniaturization and modular expansion of the energy storage battery balancing circuit and the energy storage battery equalizer.

[0017] In some embodiments, by sending a first control signal to each first switch device and outputting a second control signal to each second switch device, the first bidirectional balancing circuit and the second bidirectional balancing circuit can balance the voltage of each battery cell. In this way, it is easy to control the first bidirectional balancing circuit and the second bidirectional balancing circuit to reduce the occurrence of control error rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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.

[0019] Figure 1 One of the structural block diagrams of an energy storage battery equalization circuit according to an embodiment;

[0020] Figure 2 This is a second structural block diagram of an energy storage battery balancing circuit according to an embodiment;

[0021] Figure 3 A circuit diagram of an energy storage battery balancing circuit according to an embodiment;

[0022] Figure 4 A voltage-current characteristic diagram of an energy storage battery equalization circuit according to an embodiment;

[0023] Figure 5 The balancing mode 1 of the energy storage battery balancing circuit of one embodiment;

[0024] Figure 6 for Figure 5 The equalization mode shown is a schematic diagram of an equalization loop of a first bidirectional equalization circuit;

[0025] Figure 7 for Figure 5 The equalization loop schematic diagram of the second bidirectional equalization circuit in the equalization mode shown;

[0026] Figure 8 The second balancing mode of the energy storage battery balancing circuit of an embodiment;

[0027] Fig. 9 for Figure 8 A schematic diagram of an equalization circuit of the first bidirectional equalization circuit in equalization mode 2 is shown;

[0028] Fig.10 for Figure 8 A schematic diagram of an equalization loop of a second bidirectional equalization circuit in equalization mode 2 is shown;

[0029] Fig.11The figure is a flow chart of a method for balancing energy storage batteries according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] 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.

[0031] 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.

[0032] 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 switching device may be referred to as a second switching device, and similarly, a second switching device may be referred to as a first switching device. Both the first switching device and the second switching device are switching devices, but they are not the same switching device.

[0033] 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.

[0034] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least part of an element” means part or all of an element.

[0035] 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.

[0036] Figure 1 and Figure 2 They are respectively one of the structural block diagrams of the energy storage battery equalization circuit of an embodiment, and refer to Figure 1 and Figure 2As shown, the energy storage battery balancing circuit of this embodiment is applied to a plurality of first battery cells 110 and a plurality of second battery cells 120 alternately connected in series, wherein each first battery cell 110 and the second battery cell 120 connected in series therewith constitute a battery module 100 .

[0037] For example, the first battery cell 110 and the second battery cell 120 are battery cells with the same structure.

[0038] For example, the negative electrode of the first battery cell 110 is connected to the positive electrode of the second battery cell 120, and the negative electrode of the second battery cell 120 is connected to the positive electrode of the first battery cell 110 in the adjacent battery module 100. In this way, the positive electrode of the first battery cell 110 is the positive electrode of the corresponding battery module 100, and the negative electrode of the second battery cell 120 is the negative electrode of the corresponding battery module 100.

[0039] For example, the energy storage battery balancing circuit includes: a plurality of first bidirectional balancing circuits 200 and a plurality of second bidirectional balancing circuits 300. The first bidirectional balancing circuit 200 is connected to the battery module 100 and configured to balance the voltage of the first battery cell 110 and the voltage of the second battery cell 120 in the battery module 100. The second bidirectional balancing circuit 300 is connected to any two adjacent battery modules 100 and configured to balance the voltage of the second battery cell 120 in the first battery module 100 of the any two adjacent battery modules 100 and the voltage of the first battery cell 110 in the second battery module 100 of the any two adjacent battery modules 100.

[0040] In the above energy storage battery balancing circuit, a first bidirectional balancing circuit 200 and a second bidirectional balancing circuit 300 are respectively provided for each battery module 100. The first bidirectional balancing circuit 200 can be used to balance the voltage of the first battery cell 110 and the voltage of the second battery cell 120 in the same battery module 100, and the second bidirectional balancing circuit 300 can be used to balance the voltage of the second battery cell 120 in the first battery module 100 of any two adjacent battery modules 100 and the voltage of the first battery cell 110 in the second battery module 100 of any two adjacent battery modules 100. In this way, the energy storage battery balancing circuit can ensure that the voltages of the battery cells tend to be consistent more quickly and effectively, so as to eliminate the differences in voltages between different battery cells, and it is easy to improve the balancing speed, balancing efficiency and battery energy utilization.

[0041] In some embodiments, reference Figure 2As shown, the energy storage battery balancing circuit further includes: a first switch device 410 connected to each first battery unit 110, and a second switch device 420 connected to each second battery unit 120. The first bidirectional balancing circuit 200 and the second bidirectional balancing circuit 300 share the first switch device 410 connected to the first battery unit 110, and share the second switch device 420 connected to the second battery unit 120.

[0042] In the above energy storage battery balancing circuit, the first bidirectional balancing circuit 200 and the second bidirectional balancing circuit 300 can share the first switch device 410 connected to the corresponding first battery unit 110 and the second switch device 420 connected to the corresponding second battery unit 420 for voltage balancing; that is, the first bidirectional balancing circuit 200 and the second bidirectional balancing circuit 300 can share the switch device. In this way, the number of components used in the energy storage battery balancing circuit (such as the number of switch devices and the number of energy storage inductors) is effectively reduced, and it is also beneficial to reduce the energy transfer loss between battery cells, thereby reducing costs and reducing the circuit volume, so as to achieve miniaturization and modular expansion of the energy storage battery balancing circuit and the energy storage battery equalizer.

[0043] It should be added that the "voltage balancing" mentioned in any embodiment of the present disclosure means: making the voltages of the corresponding two battery cells tend to be consistent, for example, making the difference between the voltages of the corresponding two battery cells within a preset range. Optionally, the preset range may be that after voltage balancing, the difference between the voltages of the corresponding two battery cells is within 0mV-50mV.

[0044] It can be understood that the first bidirectional balancing circuit 200 and the second bidirectional balancing circuit 300 can be implemented by various bidirectional balancing circuits, such as based on DC / DC converters, such as bidirectional Buck (step-down)-Boost (step-up) balancing circuits or bidirectional Cuk conversion circuits, so that the voltage between battery cells can be balanced while transferring power between battery packs (PACK) to improve the balancing efficiency. The battery pack (PACK) can be composed of multiple battery modules 100 connected in series and parallel.

[0045] The following embodiments of the present disclosure exemplarily provide some possible implementations of the first bidirectional equalizing circuit 200 and the second bidirectional equalizing circuit 300 , but are not limited thereto.

[0046] In some embodiments, reference Figure 2As shown, the first switch device 410 and the second switch device 420 both have a first end and a second end. The first bidirectional balancing circuit 200 also includes: a first energy storage capacitor 210 and an energy storage inductor 220. The first energy storage capacitor 210 has a first end and a second end; the first end of the first energy storage capacitor 210 is connected to the positive electrode of the first battery unit 110 and the first end of the first switch device 410, and the second end of the first energy storage capacitor 210 is connected to the negative electrode of the second battery unit 120 and the second end of the second switch device 420. The energy storage inductor 220 has a first end and a second end; the first end of the energy storage inductor 220 is connected to the negative electrode of the first battery unit 110 and the positive electrode of the second battery unit 120, and the second end of the energy storage inductor 220 is connected to the second end of the first switch device 410 and the first end of the second switch device 420.

[0047] In some embodiments, reference Figure 2 As shown, the second bidirectional balancing circuit 300 also includes: a second energy storage capacitor 310. The second energy storage capacitor 310 has a first end and a second end; the first end of the second energy storage capacitor 310 is connected to the second end of the energy storage inductor 220 corresponding to the first battery module 100 of any two adjacent battery modules 100 and the first end of the second switch device 420 corresponding to the first battery module 100; the second end of the second energy storage capacitor 310 is connected to the second end of the energy storage inductor 220 corresponding to the second battery module 100 of any two adjacent battery modules 100 and the second end of the first switch device 410 corresponding to the second battery module 100.

[0048] Optionally, the first end of the first switch device 410 and the first end of the second switch device 420 are both drains of the corresponding switch devices. The second end of the first switch device 410 and the second end of the second switch device 420 are both sources of the corresponding switch devices.

[0049] Optionally, the number of the second bidirectional equalizing circuits 300 is equal to the number of the first bidirectional equalizing circuits 200 minus one.

[0050] In order to more clearly illustrate the energy storage battery balancing circuit provided by some embodiments of the present disclosure, Figure 3 In the figure, it is illustrated by taking the first battery unit 110 and the second battery unit 120 as the same battery unit, and the first switch device 410 and the second switch device 420 as the same switch device as an example.

[0051] Please refer to Figure 3 As shown, the energy storage battery consists of n battery cells (e.g., B1, B2, B3, ..., B n ) are connected in series in sequence, where n is an even number and is greater than or equal to 4; the battery cells corresponding to the odd numbers (e.g. B1, B3, ..., B n-1) is the first battery cell 110, and the battery cells corresponding to the even numbers (e.g., B2, B4, ..., B n ) is the second battery cell 120. In addition, the positive electrode of the first battery cell serves as the positive electrode of the entire energy storage battery, and the negative electrode of the nth battery cell serves as the negative electrode of the entire energy storage battery. The first switch device 410 and the second switch device 420 can be identified as S1, S2, S3, ..., S according to the series connection sequence of their corresponding battery cells. n , where the odd-numbered switching devices (e.g. S1, S3, ..., S n-1 ) is the first switch device 410, and the switch devices corresponding to the even numbers (such as S2, S4, ..., S n ) is the second switching device 420.

[0052] Accordingly, please refer to Figure 3 As shown, the number of the first bidirectional balancing circuits 200 is n / 2, and the number of the second bidirectional balancing circuits 300 is (n-2) / 2. In the j / 2th (j=2, 4, 6, ..., n) first bidirectional balancing circuit, the battery cell B j-1 The positive electrode and the switching device S j-1 A first end (eg, drain) of the first energy storage capacitor C1 j / 2 The first end of the battery cell B is connected to the first end of the battery cell B, which can be used as the first terminal of the first bidirectional balancing circuit 200; j-1 The negative electrode of the battery cell B j The positive electrode and energy storage inductor L j / 2 The first end of the energy storage inductor L j / 2 The second end of the switch device S j-1 The second end (eg, source) of the switching device S j The first end (eg, drain) of the battery cell B is connected to the first end (eg, drain) of the battery cell B, which can be used as the second terminal of the first bidirectional balancing circuit 200; j The negative electrode and the switching device S j The second end (eg, source) of the first energy storage capacitor C1 j / 2 The second end of the first bidirectional equalizing circuit 200 is connected to the second end of the first bidirectional equalizing circuit 200, which can serve as the third terminal of the first bidirectional equalizing circuit 200. Moreover, when j≠2, the first terminal of the j / 2th first bidirectional equalizing circuit 200 is connected to the third terminal of the (j / 2)-1th first bidirectional equalizing circuit 200.

[0053] Please continue to refer to Figure 3As shown, the structure of the [(k-2) / 2]th (k=j, k≥4) second bidirectional balancing circuit 300 is a circuit derived from the j / 2th first bidirectional balancing circuit 200, that is, the [(k-2) / 2]th (k=j, k≥4) second bidirectional balancing circuit 300 and the j / 2th first bidirectional balancing circuit 200 have a common circuit, and the common circuit can be represented by the following connection, for example: battery cell B j The negative electrode of the battery cell B in the adjacent battery module 100 j+1 The positive electrode, the switching device S j The second end (eg, source) of the battery cell B in the adjacent battery module 100 j+1 Corresponding switch device S j+1 The first end (eg, drain) of the battery cell B is connected; j The positive electrode and the energy storage inductor L j / 2 The first end of the energy storage inductor L j / 2 The second end of the switch device S j The first end (eg, drain) of the adjacent battery module 100 is connected to the second terminal of the j / 2 first bidirectional balancing circuit 200; the battery cell B in the adjacent battery module 100 j+1 The negative electrode and the corresponding energy storage inductor L (j / 2)+1 The first end of the energy storage inductor L (j / 2)+1 The second end of the corresponding switch device S j+1 The second end (eg, source) of the first bidirectional equalizing circuit 200 is connected to the second terminal (eg, source) of the first bidirectional equalizing circuit 200. On this basis, the second terminal of the first bidirectional equalizing circuit 200 of the first bidirectional equalizing circuit 200 of the second energy storage capacitor C2 is connected to the second terminal (eg, source) of the first bidirectional equalizing circuit 200 of the second energy storage capacitor C2. j / 2 The first end of the (j / 2)+1th first bidirectional equalizing circuit 200 is connected to the second energy storage capacitor C2 j / 2 The second end of is connected to each other, so that the [(k-2) / 2]th (k=j, k≥4) second bidirectional equalizing circuit 300 can be obtained.

[0054] It is worth mentioning that in some embodiments of the present disclosure, please continue to refer to Figure 3 As shown, each first switch device 410 (eg, S1, S3, ..., S n-1 ) and each second switching device 420 (eg, S2, S4, ..., S n ) also have a control terminal (such as a gate). The energy storage battery balancing circuit also includes: a control module ( Figure 3The control module is connected to the control end of each first switch device 410 and each second switch device 420, and is configured to: output a first control signal to each first switch device 410, and output a second control signal to each second switch device 420, so as to control the conduction and disconnection of the corresponding switch device respectively; wherein the first control signal and the second control signal are complementary control signals.

[0055] Optionally, the first control signal and the second control signal are both pulse width modulation (PWM) control signals, and the control waveforms of the first control signal and the second control signal are complementary.

[0056] Optionally, the control module can be, for example, a device for outputting level signals (such as an external power supply, etc.), which can control the on and off of each switching device by outputting a high level signal or a low level signal to the control end (such as a gate) of each switching device.

[0057] From the above, when the cell voltages of any one or more battery cells in the series-connected battery cells in the energy storage battery are inconsistent, the energy storage battery balancing circuit provided in the embodiment of the present disclosure can realize the energy transfer between the battery cells by controlling the first switch devices 410 and the second switch devices 420 (that is, all the switch devices). In addition, in the embodiment of the present disclosure, the control method of each switch device is simple, that is: the first switch devices 410 corresponding to the odd number are controlled by the same first control signal, and the second switch devices 420 corresponding to the even number are controlled by the same second control signal; the occurrence of control error rate can be effectively reduced.

[0058] For example, see Figure 4 As shown, under the action of the first control signal, when each first switch device 410 is turned on (for example, S1, S3, ..., S n-1 )'s gate-source drive voltages are uGS1, uGS3, ..., uGS n-1 Under the action of the second control signal, each second switch device 420 (eg, S2, S4, ..., S n ) are turned on, the gate-source drive voltages are uGS2, uGS4, ..., uGS n Correspondingly, each energy storage inductor L in the energy storage battery balancing circuit j / 2 The voltage uL across (j=2, 4, 6, ..., n) j / 2 and current iL j / 2 The waveform can be Figure 4 In addition, within a balancing cycle T of the energy storage battery balancing circuit (the balancing cycle T includes a first stage T1 and a second stage T2), the topological operation mode diagrams of the energy storage battery balancing circuit are respectively as shown in Figure 5and Figure 8 As shown in, Figure 5 Schematic diagram of the energy storage battery balancing circuit in operation mode 1 in the first stage T1. Figure 8 FIG. 1 is a schematic diagram of the energy storage battery balancing circuit in the second stage T2 in the operating mode 2. The loops formed by the energy storage battery balancing circuit in the operating modes 1 and 2 and the corresponding current flows can be seen marked in the figure.

[0059] See also Figure 5 , Figure 6 and Figure 7 As shown, in the first stage T1, each first switch device 410 (for example, S1, S3, ..., S n-1 ) are turned on at the same time, and each second switch device 420 (for example, S2, S4, ..., S n ) are turned off at the same time. Battery unit B1, switch device S1 and energy storage inductor L1 form a loop in sequence, battery unit B3, switch device S3 and energy storage inductor L2 form a loop in sequence, ..., battery unit B j-1 , Switching device S j-1 and energy storage inductor L j / 2 The circuits are formed in sequence so that the battery cells B in each circuit j-1 Give the energy storage inductor L j / 2 At the same time, the battery unit B2, the energy storage inductor L1, the switch device S1 and the first energy storage capacitor C11 sequentially form a loop ①, the battery unit B4, the energy storage inductor L2, the switch device S3 and the first energy storage capacitor C12 sequentially form a loop ①, ..., the battery unit B j , energy storage inductor L j / 2 , Switching device S j-1 and the first energy storage capacitor C1 j / 2 Forming loop ①, so that the energy stored in the first energy storage capacitor C1 j / 2 The energy in the circuit can be transferred to the energy storage inductor L through the circuit ①. j / 2 and battery cell B j At the same time, the battery unit B2, the energy storage inductor L1, the second energy storage capacitor C21 and the switch device S3 sequentially form a loop ②, the battery unit B4, the energy storage inductor L2, the second energy storage capacitor C22 and the switch device S5 sequentially form a loop ②, ..., the battery unit B k-2 , energy storage inductor L (k / 2)-1 , the second energy storage capacitor C2 (k-2) / 2 and the switching device S k-1 The circuit ② is formed in sequence so that the energy stored in the second energy storage capacitor C2 (k-2) / 2 The energy in the circuit can be transferred to the energy storage inductor L through the circuit ②. (k / 2)-1 and battery cell B k-2 Charging is performed (k=j and k≥4).

[0060] See also Figure 8 , Fig. 9 and Fig.10 As shown, in the second stage T2, each first switch device 410 (for example, S1, S3, ..., S n-1 ) are turned off at the same time, and each second switch device 420 (for example, S2, S4, ..., S n ) are turned on at the same time. Battery cell B2, energy storage inductor L1 and switch device S2 form a loop in sequence, battery cell B4, energy storage inductor L2 and switch device S2 form a loop in sequence, ..., battery cell B j , energy storage inductor L j / 2 and the switching device S j The circuit is formed in sequence so that the energy stored in the energy storage inductor L j / 2 The energy in the battery is fed to the battery unit B through each circuit. j At the same time, the battery unit B1, the first energy storage capacitor C11, the switch device S2 and the energy storage inductor L1 sequentially form a loop ①, the battery unit B3, the first energy storage capacitor C12, the switch device S4 and the energy storage inductor L2 sequentially form a loop ①, ..., the battery unit B j-1 , the first energy storage capacitor C1 j / 2 , Switching device S j and energy storage inductor L j / 2 Form a loop ① so that the energy stored in the energy storage inductor L j / 2 Energy and battery cell B j-1 Through loop ①, the first energy storage capacitor C1 is supplied j / 2 At the same time, the battery unit B3, the switch device S2, the second energy storage capacitor C21 and the energy storage inductor L2 sequentially form a loop ②, the battery unit B5, the switch device S4, the second energy storage capacitor C22 and the energy storage inductor L3 sequentially form a loop ②, ..., the battery unit B k-1 , Switching device S k-2 , the second energy storage capacitor C2 (k-2) / 2 and energy storage inductor L k / 2 The circuit ② is constructed in sequence so that the energy stored in the energy storage inductor L k / 2 Energy and battery cell B k-1 Together through loop ② to the second energy storage capacitor C2 (k -2) / 2 for charging (k=j and k≥4).

[0061] In summary, the energy storage battery balancing circuit provided by the embodiment of the present disclosure can greatly improve its overall balancing efficiency, and can also effectively realize the power transfer between battery packs when a small number of battery cells are connected in series in the battery pack. The embodiment of the present disclosure uses a combination of a first bidirectional balancing circuit and a second bidirectional balancing circuit in the energy storage battery balancing circuit to transfer the charge and discharge energy of the energy storage battery. The structure is clear and compact, and it is easy to realize modular expansion. It can effectively reduce the loss of energy transfer between battery cells or between battery packs, so as to improve the utilization rate of battery energy and realize more charge and discharge cycles, ensuring that the energy storage battery can have a longer service life and provide users with a better experience effect.

[0062] Some embodiments of the present disclosure also provide an energy storage battery equalizer, including the energy storage battery equalization circuit as described in any of the above embodiments. The energy storage battery equalizer of this embodiment can ensure that the voltages of each battery cell tend to be consistent more quickly and effectively to eliminate the differences in voltages between different battery cells, and is easy to improve the equalization speed, equalization efficiency and battery energy utilization, and effectively reduce the number of components used in the energy storage battery equalization circuit, and is also conducive to reducing the energy transfer loss between battery cells, thereby reducing costs and reducing the circuit volume, so as to achieve miniaturization and modular expansion of the energy storage battery equalization circuit and the energy storage battery equalizer.

[0063] Some embodiments of the present disclosure also provide an energy storage battery balancing method, which can be implemented by the energy storage battery balancing circuit and energy storage battery equalizer as described in any of the above embodiments. The energy storage battery balancing method can be applied to the aforementioned multiple first battery cells and multiple second battery cells alternately connected in series, and each first battery cell and the second battery cell connected in series with it constitute a battery module. Please refer to Fig.11 As shown, the energy storage battery balancing method includes the following steps S10 and S20.

[0064] S10, controlling a first bidirectional balancing circuit to balance a voltage of a first battery cell and a voltage of a second battery cell in a battery module.

[0065] S20, controlling the second bidirectional balancing circuit to balance the voltage of the second battery cell in the first battery module of any two adjacent battery modules and the voltage of the first battery cell in the second battery module of any two adjacent battery modules.

[0066] For example, the first bidirectional balancing circuit and the second bidirectional balancing circuit share a first switch device connected to the first battery unit and share a second switch device connected to the second battery unit to synchronously perform voltage balancing.

[0067] For example, in steps S10 and S20, controlling the first bidirectional balancing circuit and the second bidirectional balancing circuit to perform voltage balancing includes: sending a first control signal to each first switching device, and outputting a second control signal to each second switching device to respectively control the on and off of the corresponding switching device; wherein the first control signal and the second control signal are complementary control signals.

[0068] For example, the first control signal and the second control signal can be generated and output by the control module in the aforementioned embodiment. In addition, the relevant features of the battery module, the control module, the first bidirectional balancing circuit, the second bidirectional balancing circuit, etc. can all refer to the relevant introductions in some of the aforementioned embodiments, which will not be repeated here.

[0069] It should be understood that, although each step in the flow chart of the above-described embodiment is shown in sequence according to the indication of the arrow, these steps are not necessarily performed in sequence according to the order indicated by the arrow. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flow chart of the above-described embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0070] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0071] The technical features of the above embodiments may be arbitrarily combined. 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.

[0072] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A storage battery equalization circuit, characterized in that: Applicable to a plurality of first battery cells and a plurality of second battery cells alternately connected in series, wherein each of the first battery cells and the second battery cells connected in series therewith constitute a battery module; The energy storage battery balancing circuit comprises: A plurality of first bidirectional balancing circuits; the first bidirectional balancing circuits are connected to the battery modules correspondingly and are configured to: balance the voltage of the first battery cell and the voltage of the second battery cell in the battery module; A plurality of second bidirectional balancing circuits; the second bidirectional balancing circuits are connected to any two adjacent battery modules and are configured to: balance the voltage of the second battery cell in the first battery module of the any two adjacent battery modules and the voltage of the first battery cell in the second battery module of the any two adjacent battery modules; Wherein, the energy storage battery balancing circuit further includes: a first switch device connected to each of the first battery cells, and a second switch device connected to each of the second battery cells; The first bidirectional balancing circuit includes: a first energy storage capacitor connected in parallel to both ends of the battery module, and an energy storage inductor having a first end connected between the first battery unit and the second battery unit in the battery module and a second end connected to both ends of the first energy storage capacitor through the first switch device and the second switch device respectively; The second bidirectional balancing circuit includes: a second energy storage capacitor connected in parallel to the second ends of the two energy storage inductors corresponding to the two adjacent battery modules.

2. The energy storage battery equalization circuit according to claim 1, characterized in that: The first bidirectional balancing circuit and the second bidirectional balancing circuit share the first switching device connected to the first battery unit, and share the second switching device connected to the second battery unit.

3. The energy storage battery equalization circuit according to claim 2, characterized in that: The negative electrode of the first battery cell is connected to the positive electrode of the second battery cell, and the negative electrode of the second battery cell is connected to the positive electrode of the first battery cell in the adjacent battery module; the first switching device and the second switching device both have a first end and a second end; wherein, The first energy storage capacitor has a first end and a second end; the first end of the first energy storage capacitor is connected to the positive electrode of the first battery unit and the first end of the first switch device, and the second end of the first energy storage capacitor is connected to the negative electrode of the second battery unit and the second end of the second switch device; The energy storage inductor has a first end and a second end; the first end of the energy storage inductor is connected to the negative electrode of the first battery unit and the positive electrode of the second battery unit, and the second end of the energy storage inductor is connected to the second end of the first switching device and the first end of the second switching device.

4. The energy storage battery equalization circuit according to claim 3, characterized in that: The second energy storage capacitor has a first end and a second end; the first end of the second energy storage capacitor is connected to the second end of the energy storage inductor corresponding to the first battery module of any two adjacent battery modules and the first end of the second switching device corresponding to the first battery module; the second end of the second energy storage capacitor is connected to the second end of the energy storage inductor corresponding to the second battery module of any two adjacent battery modules and the second end of the first switching device corresponding to the second battery module.

5. The energy storage battery equalization circuit according to claim 3, characterized in that: The first end of the first switching device and the first end of the second switching device are both drains of corresponding switching devices; the second end of the first switching device and the second end of the second switching device are both sources of corresponding switching devices.

6. The energy storage battery equalization circuit according to any one of claims 2 to 5, characterized in that: The first switch device and the second switch device both have a control terminal; the energy storage battery balancing circuit also includes: a control module connected to the control terminals of the first switching devices and the second switching devices, and configured to: output a first control signal to each of the first switching devices, and output a second control signal to each of the second switching devices, so as to respectively control the on and off of the corresponding switching devices; The first control signal and the second control signal are complementary control signals.

7. An energy storage battery equalizer, characterized in that: The invention comprises the energy storage battery equalization circuit as claimed in any one of claims 1 to 6.

8. A method for balancing an energy storage battery, characterized in that: Applicable to the energy storage battery equalization circuit as described in any one of claims 1 to 6; The energy storage battery balancing method comprises: Controlling a first bidirectional balancing circuit to balance the voltage of the first battery cell and the voltage of the second battery cell in the battery module; The second bidirectional balancing circuit is controlled to balance the voltage of the second battery cell in the first battery module of any two adjacent battery modules and the voltage of the first battery cell in the second battery module of any two adjacent battery modules.

9. The energy storage battery equalization method according to claim 8, characterized in that: The first bidirectional balancing circuit and the second bidirectional balancing circuit share a first switch device connected to the first battery unit and a second switch device connected to the second battery unit to synchronously perform voltage balancing.

10. The energy storage battery equalization method according to claim 9, characterized in that: Controlling the first bidirectional balancing circuit and the second bidirectional balancing circuit to perform voltage balancing, including: sending a first control signal to each of the first switching devices, and outputting a second control signal to each of the second switching devices, so as to respectively control the conduction and disconnection of the corresponding switching devices; The first control signal and the second control signal are complementary control signals.

Images