Battery active equalization circuit and energy storage system

Abstract

The invention provides a battery active equalization circuit and an energy storage system. The battery active equalization circuit comprises a bidirectional DC conversion module; the first power supply comprises M battery cells, and M is an integer greater than or equal to 2; the M switch assemblies are connected with the M battery cells in a one-to-one correspondence mode, and the switch assemblies are connected between the battery cells and the bidirectional direct current conversion module; the control circuit is connected to the battery cell and the switch assembly; the control circuit is used for controlling the Nth battery cell to provide a control signal for the (N-1) th switch assembly so as to perform voltage equalization on any one of the first battery cell to the (N-1) th battery cell; the power supply module is connected to the Nth switch assembly and is used for providing a control signal for the Nth switch assembly so as to carry out voltage equalization on the Nth battery cell; wherein N is an integer from 2 to M. According to the battery active equalization circuit, the structure and the control process of the battery active equalization circuit can be simplified, and the cost of the battery active equalization circuit is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to a battery active balancing circuit and an energy storage system. Background Art

[0002] In related technologies, such as Figure 1 As shown, the inconsistent voltage of a single cell or multiple cells in the battery pack causes a significant drop in the battery capacity of the entire battery pack. In this case, it is usually necessary to control each switch in the switch matrix to connect the cell to a bidirectional switch circuit, so as to transfer the excess power of the cells with more power to the cells with less power, or to the entire battery string, or to charge the cells with less power separately through the total battery voltage to achieve energy transfer and balance the cell voltage.

[0003] Specifically, if Figure 2 and Figure 3 As shown, in related technologies, a dedicated control chip, such as a dedicated switch matrix driver chip from Goertek, can be used to control the switch matrix, thereby connecting each battery cell to the bidirectional switch circuit, thereby enabling charging or discharging of each battery cell and achieving voltage balancing. However, the high cost of dedicated control chips can increase the overall cost of the energy storage system.

[0004] Or, in some related technologies, such as Figure 4 As shown, an optocoupler metal-oxide semiconductor field-effect transistor (MOS) switch matrix is used in conjunction with a MOS bridge driver circuit to control the connection between each battery cell and the bidirectional switch circuit. However, the configuration of the optocoupler MOS switch matrix and the MOS bridge driver circuit not only increases the cost of the active battery balancing circuit, but also increases the area of the active battery balancing circuit and makes the control process more complicated. Summary of the Invention

[0005] The present invention aims to at least solve the technical problems in the prior art of high cost and complex control process of active battery balancing circuits.

[0006] To this end, a first aspect of the present invention provides a battery active balancing circuit.

[0007] A second aspect of the present invention provides an energy storage system.

[0008] A first aspect of the present invention provides a battery active balancing circuit, comprising: a bidirectional DC conversion module; a first power supply, the first power supply comprising M battery cells, M being an integer greater than or equal to 2; M switch components, the M switch components being connected one-to-one to the M battery cells, the switch components being connected between the battery cells and the bidirectional DC conversion module; a control circuit, connected to the battery cells and the switch components; the control circuit being used to control the Nth battery cell to provide a control signal to the N-1th switch component to control any one of the first to N-1th battery cells to be connected to the bidirectional DC conversion module, so as to perform voltage balancing on any one of the first to N-1th battery cells; a power module, the power module being connected to the Nth switch component, being used to provide a control signal to the Nth switch component to control the Nth battery cell to be connected to the bidirectional DC conversion module, so as to perform voltage balancing on the Nth battery cell; wherein N is an integer from 2 to M.

[0009] The battery active balancing circuit provided by the present invention, through the configuration of a control circuit, can provide a control signal to the Nth switch assembly through the Nth battery cell, thereby establishing connections between the first through Nth battery cells and the bidirectional DC conversion module. Simultaneously, by providing a power module, a control signal can be provided to the Nth switch assembly, establishing connections between the Nth battery cell and the bidirectional DC conversion module. This achieves connections between all battery cells and the bidirectional DC conversion module, thereby enabling voltage balancing across all battery cells. Compared to battery active balancing circuits in related arts, this circuit can effectively utilize the electrical energy provided by the Nth battery cell to provide a control signal to the Nth switch assembly. This allows for control signal transmission using a relatively simple control circuit, eliminating the need for a dedicated custom control chip to control the switch assembly, thereby reducing costs. Furthermore, the control process is relatively simple and easy to implement.

[0010] In some technical solutions, optionally, the control circuit includes: M control switches, wherein the first end of the Nth control switch is connected to the Nth battery cell, and the second end of the Nth control switch is connected to the N-1th switch component; a first controller, including M control ports, and the M control ports are respectively connected to the control ends of the M control switches; wherein the first controller is used to control the second control switch to conduct to the Nth control switch, so as to provide a control signal to the N-1th switch component through the Nth battery cell.

[0011] In this technical solution, the control circuit may include M control switches and a first controller, wherein the M control switches are the first to Nth control switches, where M is an integer greater than or equal to 2, and N is an integer from 2 to M, and the M control switches are connected to the M battery cells in a one-to-one correspondence. Specifically, the first end of the Nth control switch is connected to the Nth battery cell, and the second end of the Nth control switch is connected to the N-1th switch assembly. That is, when the Nth control switch is turned on, the power provided by the Nth battery cell can be transmitted to the N-1th switch assembly, thereby providing a control signal to the N-1th switch assembly through the Nth battery cell.

[0012] Furthermore, the control circuit also includes a first controller, which includes M control ports, and the M control ports are respectively connected to the control ends of the control switches. That is, through the first controller, the conduction and disconnection of each control switch can be controlled, thereby realizing the connection and disconnection between the Nth battery cell and the N-1th switch component, and then realizing charging or discharging of each battery cell to achieve voltage balance of the battery cells.

[0013] In some technical solutions, optionally, the control switch includes: a transistor, wherein the first end of the Nth transistor is connected to the Nth battery cell, the second end of the Nth transistor is connected to the control end of the N-1th switch component, and the control end of the Nth transistor is connected to the first controller.

[0014] In this technical solution, the control switch can be a transistor, that is, the first transistor to the Nth transistor, wherein the first end of the Nth transistor is connected to the Nth battery cell, the second end of the Nth transistor is connected to the control end of the N-1th switch component, and accordingly, the control end of the Nth transistor is connected to the first controller.

[0015] By setting the control switch as a transistor, a control signal can be transmitted to the control end of the transistor through the first controller to control the conduction state between the first end and the second end of the transistor, and then control the conduction state between the Nth battery cell and the N-1th switch component to provide a control signal for the N-1th switch component.

[0016] In some technical solutions, optionally, the control switch further includes: a current-limiting resistor connected to the first end of the transistor and the control end of the transistor.

[0017] In this technical solution, each control switch may further include a current-limiting resistor, which is connected between the first end and the control end of the transistor, thereby limiting the current between the first end and the control end of the transistor, thereby preventing the current between the first end and the control end of the transistor from being too large and causing damage to the transistor.

[0018] In some technical solutions, optionally, the first controller includes: a control chip; a plurality of switching tubes, wherein the control ends of the switching tubes are connected to the control chip; wherein one end of the Nth switching tube is connected to the control ends of the Nth battery cell and the Nth transistor, and the control chip is used to control the Nth switching tube to be turned on so that the control end of the Nth transistor receives a low-level signal and the Nth transistor is turned on so that the Nth battery cell provides a control signal for the N-1th switching component.

[0019] In this technical solution, the first controller may include a control chip and a plurality of switch tubes, and the control ends of the plurality of switch tubes are connected to the control chip, so that the conduction state of each switch tube is controlled by the control chip.

[0020] Specifically, the number of switching tubes is also M, where M is an integer greater than or equal to 2, wherein one end of the Nth switching tube is connected to the control end of the Nth battery cell and the Nth transistor, and the control chip can control the Nth switching tube to be turned on, so that the electric energy provided by the Nth battery cell can flow through the Nth switching tube, and then the level state of the control end of the Nth transistor is switched from a high level state to a low level state, so that the first end and the second end of the Nth transistor are turned on. At this time, the electric energy of the Nth battery cell can be transmitted to the N-1th switching component through the Nth transistor, so that the N-1th switching component can receive a high level signal, and the N-1th switching component is turned on to connect the N-1th battery cell to the bidirectional DC conversion module, thereby realizing voltage balancing of the N-1th battery cell.

[0021] In some technical solutions, optionally, the power supply module includes: a first isolation transformer, one end of the first isolation transformer is connected to the second power supply, and the other end of the first isolation transformer is connected to the Nth switch component.

[0022] In this technical solution, the power module may include a second power supply and a first isolation transformer, wherein one end of the first isolation transformer is connected to the second power supply, and the other end of the first isolation transformer is connected to an Nth switch assembly. When voltage balancing of the Nth battery cell is required, the first isolation transformer can be driven to transmit power provided by the second power supply to the Nth switch assembly, thereby controlling the conduction state of the Nth switch assembly to achieve voltage balancing for the Nth battery cell.

[0023] Furthermore, by providing the first isolation transformer, the current between the first power supply and the second power supply can be isolated, thereby preventing the current between the first power supply and the second power supply from being directly connected and causing damage to the battery active balancing circuit.

[0024] In some technical solutions, optionally, the power supply module further includes: a second controller connected to the first isolation transformer, configured to control the first isolation transformer to transmit the control signal provided by the second power supply to the Nth switch component.

[0025] In this technical solution, the power supply module may further include a second controller, and the second controller is connected to the first isolation transformer. Through the setting of the second controller, the first isolation transformer can be determined. When voltage balancing of the Nth battery cell is required, the first isolation transformer can be driven by the second controller to transmit the electric energy provided by the second power supply to the Nth switch component, and then the Nth battery cell is connected to the bidirectional DC conversion module to achieve voltage balancing of the Nth battery cell.

[0026] In some technical solutions, optionally, the switch assembly includes: a first switch element, wherein the first end of the first switch element is connected to the negative pole of the battery cell; a second switch element, wherein the first end of the second switch element is connected to the second end of the first switch element, and the second end of the second switch element is connected to the negative pole of the bidirectional DC conversion module; a third switch element, wherein the first end of the third switch element is connected to the positive pole of the battery cell; a fourth switch element, wherein the first end of the fourth switch element is connected to the second end of the third switch element, and the second end of the fourth switch element is connected to the positive pole of the bidirectional DC conversion module; wherein, in the first switch assembly to the N-1th switch assembly, the control end of the first switch element, the control end of the second switch element, the control end of the third switch element and the control end of the fourth switch element are all connected to the control circuit, and in the Nth switch assembly, the control end of the first switch element, the control end of the second switch element, the control end of the third switch element and the control end of the fourth switch element are all connected to the power module.

[0027] In this technical solution, the switch assembly may include a first switch element, a second switch element, a third switch element, and a fourth switch element. The first and second switches can be used to control the conduction state between the negative electrode of the battery cell and the negative electrode of the bidirectional DC conversion module. The third and fourth switches can be used to control the conduction state between the positive electrode of the battery cell and the positive electrode of the bidirectional DC conversion module.

[0028] Furthermore, in the first through N-1th switch assemblies, the control terminals of the first, second, third, and fourth switch elements are all connected to the control circuit. That is, in the first through N-1th switch assemblies, the control circuit can control the conduction states of the first, second, third, and fourth switch elements to transfer power from the Nth battery cell to the N-1th switch assembly, thereby achieving voltage balancing for the first through N-1th battery cells.

[0029] In the Nth switch assembly, the control terminals of the first switch element, the second switch element, the third switch element, and the fourth switch element are all connected to the power module. In other words, the Nth switch assembly can be controlled by the power module to achieve voltage balancing for the Nth battery cell.

[0030] In some technical solutions, optionally, the bidirectional DC conversion module includes: a second isolation transformer, one end of the second isolation transformer is connected to M switching components; a bidirectional DC conversion circuit, one end of the bidirectional DC conversion circuit is connected to the other end of the second isolation transformer, and the other end of the bidirectional DC conversion circuit is used to connect to a second power supply.

[0031] In this technical solution, the bidirectional DC conversion module may include a second isolation transformer and a bidirectional DC conversion circuit. One end of the second isolation transformer is connected to M switch assemblies, thereby controlling the conduction state between each battery cell and the second isolation transformer through the M switch assemblies, thereby achieving voltage balancing for each battery cell.

[0032] Furthermore, one end of the bidirectional DC conversion circuit is connected to the other end of the second isolation transformer, and the other end of the bidirectional DC conversion circuit is connected to the second power supply. By setting the bidirectional DC conversion circuit, the current direction can be switched. That is, when any battery cell needs to be charged, the bidirectional DC conversion circuit controls the current direction so that the electric energy of the second power supply flows to the corresponding battery cell. Conversely, when any battery cell needs to be discharged, the bidirectional DC conversion circuit controls the current direction so that the electric energy of the battery cell flows to the second power supply.

[0033] A second aspect of the present invention provides an energy storage system, comprising a battery active balancing circuit as described in any one of the above technical solutions.

[0034] The energy storage system provided by the present invention includes the battery active balancing circuit of any one of the above technical solutions. Therefore, the energy storage system includes all the beneficial effects of the battery active balancing circuit, which will not be described in detail here.

[0035] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0037] Figure 1 The structure block diagram of the active battery balancing circuit in the related art is shown;

[0038] Figure 2One of the circuit diagrams of a battery active balancing circuit in the related art is shown;

[0039] Figure 3 The second circuit diagram of the battery active balancing circuit in the related art is shown;

[0040] Figure 4 The third circuit diagram of the battery active balancing circuit in the related art is shown;

[0041] Figure 5 A circuit diagram of an active battery balancing circuit according to an embodiment of the present invention is shown;

[0042] Figure 6 A structural block diagram of an energy storage system according to an embodiment of the present invention is shown.

[0043] in, Figure 5 and Figure 6 The corresponding relationship between the reference numerals and component names is as follows:

[0044] 100 Battery active balancing circuit, 102 Bidirectional DC conversion module, 104 First power supply, 106 Battery cell, 108 Switch assembly, 110 Control switch, 112 First controller, 114 Transistor, 116 Current-limiting resistor, 118 Control chip, 120 Control circuit, 122 Power module, 124 Second power supply, 126 First isolation transformer, 128 Second controller, 130 First switch element, 132 Second switch element, 134 Third switch element, 136 Fourth switch element, 138 Second isolation transformer, 140 Bidirectional DC conversion circuit, 142 First current-limiting resistor, 144 Second current-limiting resistor, 146 Switch tube, 200 Energy storage system. DETAILED DESCRIPTION

[0045] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0047] Refer to the following Figure 5 and Figure 6 The following describes a battery active balancing circuit and an energy storage system according to some embodiments of the present invention.

[0048] Some embodiments of the present invention provide a battery active balancing circuit 100, such as Figure 5As shown, the battery active balancing circuit 100 includes: a bidirectional DC conversion module 102; a first power source 104, the first power source 104 including M battery cells 106, where M is an integer greater than or equal to 2; M switch components 108, the M switch components 108 being connected to the M battery cells 106 in a one-to-one correspondence, and the switch components 108 being connected between the battery cells 106 and the bidirectional DC conversion module 102; a control circuit 120, connected to the battery cells 106 and the switch components 108; the control circuit 120 is configured to control the Nth battery cell to provide a control signal to the N-1th switch component to control any one of the first to N-1th batteries to be connected to the bidirectional DC conversion module 102, so as to perform voltage balancing on any one of the first to N-1th batteries; and a power module 122, connected to the Nth switch component, configured to provide a control signal to the Nth switch component to control the Nth battery cell to be connected to the bidirectional DC conversion module 102, so as to perform voltage balancing on the Nth battery cell; wherein N is an integer from 2 to M.

[0049] The battery active balancing circuit 100 provided by the present invention includes a bidirectional DC conversion module 102. One side of the bidirectional DC conversion module 102 is connected to a first power source 104. The first power source 104 includes a plurality of battery cells 106. The number of battery cells 106 may be M, namely, the first battery cell to the Nth battery cell, where M is an integer greater than or equal to 2, and N is an integer from 2 to M. Accordingly, M switch assemblies 108, namely, the first switch assembly 108 to the Nth switch assembly, are connected between the bidirectional DC conversion module 102 and the plurality of battery cells 106. The M switch assemblies 108 are connected to the M battery cells 106 in a one-to-one correspondence. The configuration of the switch assemblies 108 enables connection between the battery cells 106 and the bidirectional DC conversion module 102. Specifically, the other side of the bidirectional DC conversion module 102 can also be connected to a second power supply. When the switch component 108 is turned on, the battery cell 106 can be connected to the bidirectional DC conversion module 102, so that any battery cell 106 can be charged or discharged through the second power supply, thereby achieving voltage balance of the battery cell 106.

[0050] Furthermore, the battery active balancing circuit 100 also includes a control circuit 120, which can be connected to the battery cell 106 and the switch component 108. Through the control circuit 120, the power provided by the Nth battery cell can be transmitted to the N-1th switch component, thereby providing a control signal to the N-1th switch component, thereby realizing the connection and disconnection between the N-1th battery cell and the bidirectional DC conversion module 102, and then charging or discharging the N-1th battery cell to achieve a voltage balancing process.

[0051] It is understood that by controlling the connection and disconnection between the Nth cell and the N-1th switch assembly through the control circuit 120, the power provided by the Nth cell can be effectively utilized to provide a control signal to the N-1th switch assembly. As a result, a relatively simple control circuit 120 can be used to transmit the control signal, eliminating the need for a dedicated custom control chip to control the switch assembly 108. This effectively reduces the cost of the active battery balancing circuit 100. For example, the control circuit 120 can directly utilize an analog front-end (AFE) chip, utilizing the passive balancing control pins of the AFE chip to control the connection state between the Nth cell and the N-1th switch assembly. Compared to a dedicated custom control chip, the AFE chip is less expensive, smaller, and occupies less space. Furthermore, by utilizing the power of the cell 106 to provide the control signal, the area occupied by the active battery balancing circuit 100 can be effectively reduced. Furthermore, the control process of the AFE chip is relatively simple and easy to implement.

[0052] Furthermore, in order to control the connection and disconnection between the Nth battery cell and the Nth switch component, the battery active balancing circuit 100 is further provided with a power module 122. Through the power module 122, a control signal can be provided to the Nth switch component, thereby controlling the Nth switch component, and further controlling the connection and disconnection between the Nth battery cell and the bidirectional DC conversion module 102, so as to achieve voltage balancing for the Nth battery cell.

[0053] The active battery balancing circuit 100 provided by the present invention, through the configuration of the control circuit 120, can provide a control signal to the N-th switch assembly via the N-th battery cell, thereby establishing connections between the first through N-th battery cells and the bidirectional DC conversion module 102. Simultaneously, the power module 122 can provide a control signal to the N-th switch assembly, thereby establishing connections between the N-th battery cell and the bidirectional DC conversion module 102. This effectively connects all battery cells 106 to the bidirectional DC conversion module 102, thereby achieving voltage balancing for all battery cells 106. Compared to the active battery balancing circuit 100 in the related art, this circuit can effectively utilize the power provided by the N-th battery cell to provide a control signal to the N-th switch assembly. This allows for control signal transmission using a relatively simple control circuit 120, eliminating the need for a dedicated custom control chip to control the switch assembly 108, thereby reducing costs. Furthermore, the control process is relatively simple and easy to implement.

[0054] In some embodiments, optionally, as Figure 5As shown, the control circuit 120 includes: M control switches 110, wherein the first end of the Nth control switch is connected to the Nth battery cell, and the second end of the Nth control switch is connected to the N-1th switch component; a first controller 112, including M control ports, and the M control ports are respectively connected to the control ends of the M control switches 110; wherein the first controller 112 is used to control the second control switch 110 to be turned on to provide a control signal to the N-1th switch component through the Nth battery cell.

[0055] In this embodiment, the control circuit 120 may include M control switches 110 and a first controller 112, wherein the M control switches 110 are the first control switch 110 to the Nth control switch, where M is an integer greater than or equal to 2, and N is an integer from 2 to M, and the M control switches 110 are connected one-to-one with the M battery cells 106. Specifically, the first end of the Nth control switch is connected to the Nth battery cell, and the second end of the Nth control switch is connected to the N-1th switch assembly. That is, when the Nth control switch is turned on, it can transmit the power provided by the Nth battery cell to the N-1th switch assembly, thereby providing a control signal to the N-1th switch assembly through the Nth battery cell.

[0056] Furthermore, the control circuit 120 also includes a first controller 112, and the control port of the first controller 112 is connected to the control end of the control switch 110. That is, through the first controller 112, the conduction and disconnection of each control switch 110 can be controlled, thereby realizing the connection and disconnection between the Nth battery cell and the N-1th switch component, and then realizing charging or discharging of each battery cell 106 to achieve voltage balance of the battery cell 106.

[0057] For example, Figure 5 As shown, the number of battery cells 106 can be four, namely cell 1 to cell 4. Correspondingly, the number of switch components 108 is also four, namely the first switch component to the fourth switch component, and the number of control switches 110 is also four, namely the first control switch to the fourth control switch. When the voltage of cell 3 is low or high, the first controller 112 can control the fourth control switch to conduct, thereby transferring the power of cell 4 to the third switch component, and then provide a control signal to the third switch component to conduct the third switch component, so that cell 3 can be connected to the bidirectional DC conversion module 102 to realize charging or discharging of cell 3, thereby achieving voltage balancing of cell 3. Figure 5 VC4 indicates connection to cell4, VC3 indicates connection to cell3, VC2 indicates connection to cell2, and VC1 indicates connection to cell1.

[0058] In some embodiments, optionally, as Figure 5As shown, the control switch 110 includes: a transistor 114, wherein the first end of the Nth transistor is connected to the Nth battery cell, the second end of the Nth transistor is connected to the control end of the N-1th switch component, and the control end of the Nth transistor is connected to the first controller 112.

[0059] In this embodiment, the control switch 110 can be a transistor 114, that is, a first transistor to an Nth transistor, wherein the first end of the Nth transistor is connected to the Nth battery cell, the second end of the Nth transistor is connected to the control end of the N-1th switch component, and accordingly, the control end of the Nth transistor is connected to the first controller 112.

[0060] By setting the control switch 110 to transistor 114, a control signal can be transmitted to the control end of transistor 114 through the first controller 112 to control the conduction state between the first end and the second end of transistor 114, and then control the conduction state between the Nth battery cell and the N-1th switch component to provide a control signal for the N-1th switch component.

[0061] For example, Figure 5 As shown, the number of battery cells 106 can be four, namely cell 1 to cell 4. Correspondingly, the number of switch components 108 is also four, namely the first switch component to the fourth switch component, and the number of transistors 114 is also four, namely the first transistor to the fourth transistor. When the voltage of cell 3 is low or high, the first controller 112 can control the control terminal of the fourth transistor to conduct between the first terminal and the second terminal of the fourth transistor, thereby transmitting the power of cell 4 to the third switch component, and then providing a control signal to the third switch component to conduct the third switch component, so that cell 3 can be connected to the bidirectional DC conversion module 102 to realize charging or discharging of cell 3, thereby realizing voltage balancing of cell 3. Figure 5 VC4 indicates connection to cell4, VC3 indicates connection to cell3, VC2 indicates connection to cell2, and VC1 indicates connection to cell1.

[0062] Furthermore, if Figure 5 As shown, the control switch 110 further includes a current limiting resistor 116 , which is connected to the first terminal of the transistor 114 and the control terminal of the transistor 114 .

[0063] In this embodiment, each control switch 110 may further include a current-limiting resistor 116, which is connected between the first end and the control end of the transistor 114, thereby limiting the current between the first end and the control end of the transistor 114, thereby preventing the current between the first end and the control end of the transistor 114 from being too large and causing damage to the transistor 114.

[0064] Specifically, the current limiting resistor 116 may include a first current limiting resistor 142 and a second current limiting resistor 144, wherein one end of the first current limiting resistor 142 is connected to the first end of the transistor 114, one end of the second current limiting resistor 144 is connected to the other end of the first current limiting resistor 142, and the other end of the second current limiting resistor 144 is connected to the control end of the transistor 114.

[0065] In some embodiments, optionally, as Figure 5 As shown, the first controller 112 includes: a control chip 114; a plurality of switch tubes 146, and the control end of the switch tube 146 is connected to the control chip 114; wherein, one end of the Nth switch tube is connected to the control end of the Nth battery cell and the Nth transistor, and the control chip 114 is used to control the Nth switch tube to be turned on so that the control end of the Nth transistor receives a low-level signal and the Nth transistor is turned on, so that the Nth battery cell provides a control signal for the N-1th switch component.

[0066] In this embodiment, the first controller 112 may include a control chip 114 and multiple switch tubes 146 , and the control ends of the multiple switch tubes 146 are connected to the control chip 114 , so that the conduction state of each switch tube 146 is controlled by the control chip 114 .

[0067] Specifically, the number of switching tubes 146 is also M, where M is an integer greater than or equal to 2, wherein one end of the Nth switching tube is connected to the control end of the Nth battery cell and the Nth transistor, and the control chip 114 can control the Nth switching tube to be turned on, so that the electric energy provided by the Nth battery cell can flow through the Nth switching tube, and then the level state of the control end of the Nth transistor is switched from a high level state to a low level state, so that the first end and the second end of the Nth transistor are turned on. At this time, the electric energy of the Nth battery cell can be transmitted to the N-1th switching component through the Nth transistor, so that the N-1th switching component can receive a high level signal, and the N-1th switching component is turned on to connect the N-1th battery cell to the bidirectional DC conversion module 102, thereby achieving voltage balancing of the N-1th battery cell.

[0068] For example, Figure 5As shown, the number of battery cells 106 can be four, namely cell 1 to cell 4. Correspondingly, the number of switch components 108 is also four, namely the first to fourth switch components, the number of transistors 114 is also four, namely the first to fourth transistors, and the number of switch tubes 146 is also four, namely the first to fourth switch tubes. When the voltage of cell 3 is low or high, the control chip 114 controls the fourth switch tube to conduct, thereby allowing the power of cell 4 to flow through the fourth switch tube, thereby causing the level state of the control terminal of the fourth transistor to change from a high level state to a low level state, thereby conducting between the first terminal and the second terminal of the fourth transistor, thereby transmitting the power of cell 4 to the third switch component, and then providing a high level signal to the third switch component to conduct the third switch component, so that cell 3 can be connected to the bidirectional DC conversion module 102 to charge or discharge cell 3, thereby achieving voltage balancing of cell 3. Figure 5 VC4 indicates connection to cell4, VC3 indicates connection to cell3, VC2 indicates connection to cell2, and VC1 indicates connection to cell1.

[0069] In some embodiments, optionally, as Figure 5 As shown, the power module 122 includes a first isolation transformer 126 , one end of the first isolation transformer 126 is connected to the second power source 124 , and the other end of the first isolation transformer 126 is connected to the Nth switch assembly.

[0070] In this embodiment, the power module 122 may include a second power supply 124 and a first isolation transformer 126, wherein one end of the first isolation transformer 126 is connected to the second power supply 124, and the other end of the first isolation transformer 126 is connected to the Nth switch assembly. When voltage balancing of the Nth battery cell is required, the first isolation transformer 126 may be driven to transmit power provided by the second power supply 124 to the Nth switch assembly, thereby controlling the conduction state of the Nth switch assembly to achieve voltage balancing for the Nth battery cell.

[0071] Furthermore, the first isolation transformer 126 can be used to isolate the current between the first power source 104 and the second power source 124 , thereby preventing the current between the first power source 104 and the second power source 124 from being directly connected and causing damage to the active battery balancing circuit 100 .

[0072] Furthermore, if Figure 5 As shown, the power module 122 further includes: a second controller 128 connected to the first isolation transformer 126, for controlling the first isolation transformer 126 to transmit the control signal provided by the second power supply 124 to the Nth switch component.

[0073] Specifically, the power supply module 122 can also include a second controller 128, and the second controller 128 is connected to the first isolation transformer 126. Through the setting of the second controller 128, the first isolation transformer 126 can be determined. When it is necessary to perform voltage balancing on the Nth battery cell, the first isolation transformer 126 can be driven by the second controller 128 to transmit the electric energy provided by the second power supply 124 to the Nth switch component, and then connect the Nth battery cell to the bidirectional DC conversion module 102 to achieve voltage balancing of the Nth battery cell.

[0074] In some embodiments, optionally, as Figure 5 As shown, the switch assembly 108 includes: a first switch 130, a first end of the first switch 130 is connected to the negative electrode of the battery cell 106; a second switch 132, a first end of the second switch 132 is connected to the second end of the first switch 130, and a second end of the second switch 132 is connected to the negative electrode of the bidirectional DC conversion module 102; a third switch 134, a first end of the third switch 134 is connected to the positive electrode of the battery cell 106; a fourth switch 136, a first end of the fourth switch 136 is connected to the second end of the third switch 134, and a fourth switch The second end of the switch element 136 is connected to the positive pole of the bidirectional DC conversion module 102; wherein, in the first switch component to the N-1 switch component, the control end of the first switch component 130, the control end of the second switch component 132, the control end of the third switch component 134 and the control end of the fourth switch component 136 are all connected to the control circuit 120, and in the Nth switch component, the control end of the first switch component 130, the control end of the second switch component 132, the control end of the third switch component 134 and the control end of the fourth switch component 136 are all connected to the power module 122.

[0075] In this embodiment, the switch assembly 108 may include a first switch 130, a second switch 132, a third switch 134, and a fourth switch 136. The first end of the first switch 130 is connected to the negative electrode of the battery cell 106, the first end of the second switch 132 is connected to the second end of the first switch 130, and the second end of the second switch 132 is connected to the negative electrode of the bidirectional DC conversion module 102. In other words, the first and second switches 130, 132 are used to control the conduction state between the negative electrode of the battery cell 106 and the negative electrode of the bidirectional DC conversion module 102. Accordingly, the first end of the third switch 134 is connected to the positive electrode of the battery cell 106, the first end of the fourth switch 134 is connected to the second end of the third switch 134, and the second end of the fourth switch 136 is connected to the positive electrode of the bidirectional DC conversion module 102. In other words, the third and fourth switches 134, 136 are used to control the conduction state between the positive electrode of the battery cell 106 and the positive electrode of the bidirectional DC conversion module 102. When the first switch 130 , the second switch 132 , the third switch 134 and the fourth switch 136 are all turned on, the positive and negative electrodes of the battery cell 106 are respectively connected to the positive and negative electrodes of the bidirectional DC conversion module 102 , thereby enabling charging and discharging of the battery cell 106 .

[0076] Furthermore, in the first to N-1th switch assemblies, the control end of the first switch element 130, the control end of the second switch element 132, the control end of the third switch element 134, and the control end of the fourth switch element 136 are all connected to the control circuit 120. That is, in the first to N-1th switch assemblies, the conductive states of the first switch element 130, the second switch element 132, the third switch element 134, and the fourth switch element 136 can be controlled by the control circuit 120 to transmit the power of the Nth battery cell to the N-1th switch assembly, thereby achieving voltage balancing of the first to N-1th battery cells.

[0077] In the Nth switch assembly, the control terminals of the first switch element 130, the second switch element 132, the third switch element 134, and the fourth switch element 136 are all connected to the power module 122. That is, the Nth switch assembly can be controlled by the power module 122 to achieve voltage balancing for the Nth battery cell.

[0078] In some embodiments, optionally, as Figure 5 As shown, the bidirectional DC conversion module 102 includes: a second isolation transformer 138, one end of the second isolation transformer 138 is connected to M switch components 108; a bidirectional DC conversion circuit 140, one end of the bidirectional DC conversion circuit 140 is connected to the other end of the second isolation transformer 138, and the other end of the bidirectional DC conversion circuit 140 is used to connect to the second power supply 124.

[0079] In this embodiment, the bidirectional DC conversion module 102 may include a second isolation transformer 138 and a bidirectional DC conversion circuit 140. One end of the second isolation transformer 138 is connected to M switch components 108, so that the M switch components 108 can control the conduction state between each battery cell 106 and the second isolation transformer 138, thereby achieving voltage balancing for each battery cell 106.

[0080] Furthermore, one end of the bidirectional DC conversion circuit 140 is connected to the other end of the second isolation transformer 138, and the other end of the bidirectional DC conversion circuit 140 is connected to the second power source 124. The bidirectional DC conversion circuit 140 is configured to switch the direction of the current. That is, when any battery cell 106 needs to be charged, the bidirectional DC conversion circuit 140 controls the direction of the current so that the power from the second power source 124 flows to the corresponding battery cell 106. Conversely, when any battery cell 106 needs to be discharged, the bidirectional DC conversion circuit 140 controls the direction of the current so that the power from the battery cell 106 flows to the second power source 124.

[0081] Some embodiments of the present invention provide an energy storage system 200, such as Figure 6 As shown, the energy storage system 200 includes: a battery active balancing circuit 100 as any one of the above technical solutions.

[0082] The energy storage system 200 provided by the present invention includes the active battery balancing circuit 100 of any one of the above technical solutions. Therefore, the energy storage system 200 includes all the beneficial effects of the active battery balancing circuit 100, which will not be described in detail here.

[0083] In the description of the present invention, the term "plurality" refers to two or more than two. Unless otherwise expressly defined, the orientations or positional relationships indicated by the terms "upper" and "lower" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "connect," "install," and "fix" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0084] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0085] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A battery active balancing circuit, characterized in that: include: Bidirectional DC conversion module; A first power supply, comprising M battery cells, where M is an integer greater than or equal to 2; M switch assemblies, the M switch assemblies being connected to the M battery cells in a one-to-one correspondence, and the switch assemblies being connected between the battery cells and the bidirectional DC conversion module; a control circuit connected to the battery cell and the switch assembly; The control circuit is used to control the Nth battery cell to provide a control signal to the N-1th switch component, so as to control any one of the first battery cell to the N-1th battery cell to be connected to the bidirectional DC conversion module, so as to perform voltage balancing on any one of the first battery cell to the N-1th battery cell; a power module connected to an Nth switch assembly, configured to provide a control signal to the Nth switch assembly to control the Nth battery cell to be connected to the bidirectional DC conversion module, so as to perform voltage balancing on the Nth battery cell; Wherein, N is an integer from 2 to M.

2. The battery active balancing circuit according to claim 1, wherein: The control circuit comprises: M control switches, wherein a first end of the Nth control switch is connected to the Nth battery cell, and a second end of the Nth control switch is connected to the N-1th switch assembly; A first controller includes M control ports, wherein the M control ports are respectively connected to the control ends of the M control switches; The first controller is used to control the second control switch to turn on the Nth control switch, so as to provide a control signal to the N-1th switch component through the Nth battery cell.

3. The battery active balancing circuit according to claim 2, wherein: The control switch includes: A transistor, wherein a first end of the Nth transistor is connected to the Nth battery cell, a second end of the Nth transistor is connected to a control end of an N-1th switch component, and the control end of the Nth transistor is connected to the first controller.

4. The battery active balancing circuit according to claim 3, wherein: The control switch further includes: A current limiting resistor, wherein two ends of the current limiting resistor are connected to the first end of the transistor and the control end of the transistor.

5. The battery active balancing circuit according to claim 2, wherein: The first controller includes: Control chip; A plurality of switch tubes, wherein control ends of the switch tubes are connected to the control chip; Among them, one end of the Nth switching tube is connected to the Nth battery cell and the control end of the Nth transistor, and the control chip is used to control the conduction of the Nth switching tube so that the control end of the Nth transistor receives a low-level signal, and the Nth transistor is turned on, so that the Nth battery cell provides a control signal for the N-1th switching component.

6. The battery active balancing circuit according to any one of claims 1 to 5, characterized in that: The power module includes: A first isolation transformer, one end of the first isolation transformer is connected to a second power source, and the other end of the first isolation transformer is connected to the Nth switch component.

7. The battery active balancing circuit according to claim 6, wherein: The power module further includes: The second controller is connected to the first isolation transformer and is used to control the first isolation transformer to transmit the control signal provided by the second power supply to the Nth switch component.

8. The battery active balancing circuit according to any one of claims 1 to 5, characterized in that: The switch assembly comprises: a first switch element, wherein a first end of the first switch element is connected to the negative electrode of the battery cell; a second switch element, wherein a first end of the second switch element is connected to a second end of the first switch element, and a second end of the second switch element is connected to a negative electrode of the bidirectional DC conversion module; a third switch element, wherein a first end of the third switch element is connected to the positive electrode of the battery cell; a fourth switch element, wherein a first end of the fourth switch element is connected to the second end of the third switch element, and a second end of the fourth switch element is connected to the positive electrode of the bidirectional DC conversion module; Among them, in the first switch component to the N-1th switch component, the control end of the first switch component, the control end of the second switch component, the control end of the third switch component and the control end of the fourth switch component are all connected to the control circuit, and in the Nth switch component, the control end of the first switch component, the control end of the second switch component, the control end of the third switch component and the control end of the fourth switch component are all connected to the power module.

9. The battery active balancing circuit according to any one of claims 1 to 5, characterized in that: The bidirectional DC conversion module includes: a second isolation transformer, one end of the second isolation transformer being connected to the N switch assemblies; A bidirectional DC conversion circuit, one end of which is connected to the other end of the second isolation transformer, and the other end of which is used to be connected to a second power supply.

10. An energy storage system, characterized in that: include: The battery active balancing circuit according to any one of claims 1 to 9.

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