Energy storage assembly, balance control method and balance control device thereof and energy storage system

Abstract

The invention provides an energy storage assembly, a balance control method and device thereof and an energy storage system, and relates to the technical field of battery energy storage. The energy storage assembly comprises an energy storage module, and the energy storage module comprises N battery cells; the active equalization module comprises a one-way flyback power supply; the first switch matrix comprises N first switch units; a passive equalization module, wherein the passive equalization module comprises N equalization resistors; a second switch matrix; the control module is electrically connected with the battery cells, the active equalization module and the passive equalization module, and the control module is used for controlling the active equalization module to carry out active charging equalization on the N battery cells according to the battery cell voltages of the N battery cells; and / or controlling the passive equalization module to carry out passive discharge equalization on the N battery cells. According to the invention, discharging equalization of the battery cells with relatively high battery cell voltage and charging equalization of the battery cells with relatively low battery cell voltage can be realized at the same time, and the battery cell electric quantity equalization efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of battery energy storage technology, and in particular to an energy storage component and a balancing control method thereof, a balancing control device, and an energy storage system. Background Art

[0002] As the capacity of energy storage cells continues to increase, researchers are beginning to focus on voltage consistency within each cell to prevent a significant drop in the overall battery pack capacity due to a voltage mismatch within a single cell. Due to the increased capacity of individual cells, earlier passive balancing solutions are no longer able to adequately meet these cell consistency requirements.

[0003] In order to achieve consistency between different battery cells, balancing control methods generally include active balancing and passive balancing. Figure 5 The figure shows the circuit topology of a typical single cell passive balancing solution in the related art. Figure 6 The following figure shows the circuit topology of a typical single-cell active charge balancing solution in related technologies. Active balancing transfers power from cells with high charge to cells with low charge. Passive balancing dissipates excess energy from high-voltage cells through methods such as heat dissipation. However, the active charge balancing method described above is only applicable to balancing a single cell at a time and cannot balance multiple cells simultaneously, resulting in low balancing efficiency. Passive balancing can only discharge and balance cells with high cell voltages and cannot charge and balance cells with low cell voltages. Summary of the Invention

[0004] The present application aims to at least solve the technical problem of low cell balancing efficiency in the prior art or related art.

[0005] To this end, a first aspect of the present application provides an energy storage assembly.

[0006] A second aspect of the present application provides a method for balancing control of an energy storage component.

[0007] A third aspect of the present application provides a balancing control device for an energy storage component.

[0008] A fourth aspect of the present application provides an energy storage system.

[0009] In view of this, the first aspect of the present application provides an energy storage component, including: an energy storage module, the energy storage module includes N battery cells, N is a positive integer greater than 1; an active balancing module, the active balancing module includes: a unidirectional flyback power supply; a first switch matrix, the first switch matrix includes N first switch units, the first end of each of the N first switch units is electrically connected to the unidirectional flyback power supply, and the second end of each of the N first switch units is electrically connected to the N battery cells; a passive balancing module, the passive balancing module includes: N balancing resistors; a second switch matrix, the second switch matrix includes N second switch units; wherein each of the N balancing resistors is electrically connected to a corresponding battery cell through a corresponding second switch unit; a control module, the control module is electrically connected to the battery cell, the active balancing module and the passive balancing module, and the control module is used to control the active balancing module to actively charge and balance the N battery cells according to the battery cell voltages of the N battery cells; and / or control the passive balancing module to passively discharge and balance the N battery cells.

[0010] The energy storage assembly of the present application is provided with both an active balancing module and a passive balancing module, so that the battery cells with higher battery voltages and the battery cells with lower battery voltages can be simultaneously balanced, thereby improving the battery cell balance efficiency.

[0011] In some technical solutions of the present application, optionally, the control module includes: a controller, which is communicatively connected to the unidirectional flyback power supply; an optocoupler drive module, which is communicatively connected to the controller and to the active balancing module; wherein the controller is used to control the unidirectional flyback power supply to start working when the cell voltage of the first battery cell among N battery cells is less than the cell voltages of other battery cells among the N battery cells, and the difference between the cell voltage of the first battery cell and the cell voltages of the other battery cells is greater than the active balancing threshold, and output an enable signal to the optocoupler drive module, so that the optocoupler drive module controls the first switch unit electrically connected to the first battery cell to close, so as to charge and balance the first battery cell through the unidirectional flyback power supply.

[0012] By setting up an optocoupler drive module, this application can achieve signal isolation between the MCU side and the energy storage circuit side, block common-mode interference and ground loop current, and improve system safety and anti-interference capabilities.

[0013] In some technical solutions of the present application, optionally, the control module also includes: an analog front-end module, which maintains electrical connection with N battery cells and is communicatively connected with the controller, and the analog front-end module is used to collect the cell voltage of each battery cell; wherein, when the cell voltage of the second battery cell among the N battery cells is greater than the cell voltages of other battery cells among the N battery cells, and the difference between the cell voltage of the second battery cell and the cell voltage of the other battery cells is greater than the passive balancing threshold, the analog front-end module controls the second switch unit electrically connected to the second battery cell to close, so as to discharge and balance the second battery cell through the balancing resistor.

[0014] This application uses an analog front-end module to collect the cell voltage of a single battery cell. When the cell voltage of the second battery cell is too high, the second switch unit is controlled to close to turn on the discharge circuit between the second battery cell and the balancing resistor, and the balancing resistor is heated to achieve passive discharge balancing of the battery cell with too high cell voltage.

[0015] In some technical solutions of the present application, optionally, the optocoupler driving module includes N digital isolation optocouplers, which are electrically connected to the control ends of the N first switch units respectively, and the digital isolation optocouplers are used to control the first switch units to close or open.

[0016] This application provides independent digital isolation optocouplers to actively control the charge balancing of each individual battery cell, thereby improving system safety and reliability and enhancing the system's anti-interference ability.

[0017] In some technical solutions of the present application, optionally, the energy storage component further includes: a power supply module, the power supply module is electrically connected to the optocoupler driving module, and the power supply module is used to supply power to the optocoupler driving module.

[0018] In this technical solution, the energy storage component includes a power supply module, which can power the optocoupler driver module, specifically each digital isolation optocoupler in the optocoupler driver module. Exemplarily, the power supply module is a DC power supply module.

[0019] In some technical solutions of the present application, optionally, the first switching unit includes: a first sub-switch device, the first end of the first sub-switch device is electrically connected to the positive pole of the unidirectional flyback power supply, and the second end of the first sub-switch device is electrically connected to the positive pole of the battery cell; a second sub-switch device, the second end of the second sub-switch device is electrically connected to the negative pole of the unidirectional flyback power supply, and the second end of the second sub-switch device is electrically connected to the negative pole of the battery cell; wherein the switching states of the first sub-switch device and the second sub-switch device are the same.

[0020] The present application can improve the reliability of the active balancing module by separately providing the first sub-switch device and the second sub-switch device.

[0021] In some technical solutions of the present application, optionally, the first sub-switching device and the second sub-switching device are both N-type metal-oxide-semiconductor transistors.

[0022] In this technical solution, both the first and second sub-switching devices are N-type metal-oxide-semiconductor (NMOS) transistors. Active balancing of cells with lower voltages is achieved through a first switch matrix consisting of a controller, an optocoupler driver module, a unidirectional flyback power supply, and NMOS. This simple logic solves the relatively complex logic execution problem in scenarios where a single cell has low voltage.

[0023] In some technical solutions of the present application, optionally, the second switching unit is a P-type metal-oxide-semiconductor transistor.

[0024] In this technical solution, the second switching unit is a P-type metal-oxide-semiconductor transistor (P-Meta-Oxied-Semiconductor, PMOS). By controlling the second switch matrix composed of PMOS by the AFE module and combining it with a passive balancing strategy for balancing resistance heating, efficient cell discharge and heating balancing can be achieved. By combining the passive balancing control method of the second switch matrix composed of PMOS with the AFE module, and the active balancing control method of the first switch matrix composed of a controller, an optocoupler drive module, a unidirectional flyback power supply and NMOS, the second cell with an excessively high cell voltage and the first cell with an excessively low cell voltage can be balanced at the same time, thereby improving the cell balancing efficiency.

[0025] The second aspect of the present application provides a balancing control method for an energy storage component, which is executed by the energy storage component provided in any of the above technical solutions. The balancing control method includes: obtaining the cell voltage of each of N battery cells; and performing active charge balancing and / or passive discharge balancing on the N battery cells according to the cell voltage.

[0026] The energy storage assembly of the present application is provided with both an active balancing module and a passive balancing module, so that the battery cells with higher battery voltages and the battery cells with lower battery voltages can be simultaneously balanced, thereby improving the battery cell balance efficiency.

[0027] In some technical solutions of the present application, optionally, the energy storage component includes a unidirectional flyback power supply, which actively charges and balances N battery cells according to the battery cell voltage, including: when the cell voltage of a first battery cell among the N battery cells is less than the cell voltage of other battery cells among the N battery cells, and the difference between the cell voltage of the first battery cell and the cell voltage of the other battery cells is greater than the active balancing threshold, controlling the unidirectional flyback power supply to start working, and controlling the first switch unit electrically connected to the first battery cell to close, so as to charge and balance the first battery cell through the unidirectional flyback power supply.

[0028] In this technical solution, when the cell voltage of the first battery cell is lower than the cell voltage of other battery cells, and the voltage difference between the cell voltage of the first battery cell and the cell voltage of other battery cells exceeds the set active balancing threshold, the controller starts to actively charge and balance the first battery cell. At this time, the controller controls the unidirectional flyback power supply to start working and outputs an enable signal to the optocoupler drive module. When the optocoupler drive module receives the enable signal, it controls the first switch unit connected to the first battery cell to close. At this time, the charging circuit between the first battery cell and the unidirectional flyback power supply is connected, and the unidirectional flyback power supply starts to charge and balance the first battery cell, thereby increasing the cell voltage of the first battery cell and achieving active balancing.

[0029] In some technical solutions of the present application, optionally, passive discharge balancing is performed on N battery cells based on the battery cell voltage, including: when the battery cell voltage of the second battery cell among the N battery cells is greater than the battery cell voltages of other battery cells among the N battery cells, and the difference between the battery cell voltage of the second battery cell and the battery cell voltages of other battery cells is greater than the passive balancing threshold, controlling the second switch unit electrically connected to the second battery cell to close, so as to discharge balance the second battery cell through the balancing resistor.

[0030] In this technical solution, when the cell voltage of the second battery cell is higher than the cell voltage of other battery cells, and the voltage difference between the cell voltage of the second battery cell and the cell voltage of other battery cells exceeds the set passive balancing threshold, the second switch unit electrically connected to the second battery cell is controlled to close. At this time, the discharge circuit between the second battery cell and the balancing resistor is turned on, and the second battery cell will release current to the balancing resistor. This part of the current can form Joule heat on the balancing resistor, thereby consuming part of the energy and achieving passive balancing of the second battery cell.

[0031] The third aspect of the present application provides a balancing control device for an energy storage component, which is applied to an energy storage component provided in any of the above technical solutions. The balancing control device includes: an acquisition module for obtaining the cell voltage of each of N battery cells; and a balancing module for actively charging and / or passively discharging the N battery cells according to the cell voltage.

[0032] The energy storage assembly of the present application is provided with both an active balancing module and a passive balancing module, so that the battery cells with higher battery voltages and the battery cells with lower battery voltages can be simultaneously balanced, thereby improving the battery cell balance efficiency.

[0033] In a fourth aspect, the present application provides an energy storage system, comprising: a battery module comprising a plurality of battery cells; a battery management system comprising an energy storage component as provided in any of the above technical solutions, and performing balanced control of the power of the plurality of battery cells in the battery module based on the energy storage component; and / or executing a balanced control method as proposed in any of the above technical solutions, thereby also achieving the same technical effect. To avoid repetition, it will not be described here. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0035] Figure 1 A structural block diagram of an energy storage assembly in some embodiments of the present application is shown;

[0036] Figure 2 A balancing circuit diagram of an energy storage assembly according to some embodiments of the present application is shown;

[0037] Figure 3 A flow chart showing a method for balancing control of energy storage components according to some embodiments of the present application is provided;

[0038] Figure 4 A structural block diagram of a balancing control device for an energy storage assembly according to some embodiments of the present application is shown;

[0039] Figure 5 The following is a circuit topology diagram of a typical single cell passive balancing solution in the related art;

[0040] Figure 6 The figure shows a typical circuit topology diagram of a single cell active charging and balancing solution in the related art.

[0041] Reference numerals:

[0042] 10 energy storage components, 11 energy storage modules, 112 battery cells;

[0043] 12 active balancing module, 120 unidirectional flyback power supply, 122 first switch matrix, 1220 first switch unit, 1222 first sub-switch device, 1224 second sub-switch device;

[0044] 13 passive balancing module, 130 balancing resistor, 132 second switch matrix, 1320 second switch unit;

[0045] 14 control module, 140 controller, 142 optocoupler driver module, 1422 digital isolation optocoupler, 144 analog front-end module;

[0046] 15 power supply modules. DETAILED DESCRIPTION

[0047] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0048] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0049] Refer to the following Figures 1 to 4 The energy storage assembly 10 and its control method, device, readable storage medium and energy storage system provided according to some embodiments of the present application are described.

[0050] In some embodiments of the present application, an energy storage assembly 10 is provided. Figure 1 shows a structural block diagram of the energy storage assembly 10 of some embodiments of the present application, Figure 2 The balancing circuit diagram of the energy storage assembly 10 of some embodiments of the present application is shown as follows: Figure 1 and Figure 2As shown, the energy storage component 10 includes: an energy storage module 11, the energy storage module 11 includes N battery cells 112, N is a positive integer greater than 1; an active balancing module 12, the active balancing module 12 includes: a unidirectional flyback power supply 120; a first switch matrix 122, the first switch matrix 122 includes N first switch units 1220, the first end of each first switch unit 1220 in the N first switch units 1220 is electrically connected to the unidirectional flyback power supply 120, and the second end of each first switch unit 1220 in the N first switch units 1220 is electrically connected to the N battery cells 112; a passive balancing module 13, the passive balancing module 13 includes: N a balancing resistor 130; a second switch matrix 132, the second switch matrix 132 includes N second switch units 1320; wherein each of the N balancing resistors 130 is electrically connected to a corresponding battery cell 112 through a corresponding second switch unit 1320; a control module 14, the control module 14 is electrically connected to the battery cell 112, the active balancing module 12 and the passive balancing module 13, and the control module 14 is used to control the active balancing module 12 to actively charge and balance the N battery cells 112 according to the battery cell voltages of the N battery cells 112; and / or control the passive balancing module 13 to passively discharge and balance the N battery cells 112.

[0051] In this embodiment, Figure 1 and Figure 2 The arrows shown in the figure indicate the direction of electrical signal transmission. The energy storage assembly 10 includes an energy storage module 11, an active balancing module 12, a passive balancing module 13, and a control module 14. The energy storage module 11 includes N battery cells 112, illustratively connected in parallel. For example, N = 2, 3, 4, etc. During the charging and discharging process of the energy storage assembly 10, due to consistency issues among the different battery cells 112, the charging and discharging speeds of different battery cells 112 may vary, resulting in different battery voltages for different battery cells 112. Due to the "barrel principle," in a discharging scenario, when the battery voltage of one of the battery cells 112 drops below the discharge threshold, all of the battery cells 112 will stop discharging, resulting in energy waste. In a charging scenario, when the battery voltage of one of the battery cells 112 rises above the full charge threshold, all of the battery cells 112 will stop charging, resulting in a decrease in the total charge of the energy storage assembly 10.

[0052] In related technologies, in order to achieve consistency between different cells, balancing control methods generally include active balancing and passive balancing. Among them, the principle of passive balancing of single cells is: for single cells with high voltage, by controlling external switches, the energy of the single cells is dissipated in the form of resistance heat consumption, thereby achieving the purpose of balancing the cells with high voltage. Figure 5As shown in Figure 1, the circuit topology of a typical single-cell passive balancing solution includes single-cells Cell 1, Cell 12, Cell 3, and Cell 4; balancing resistors 1, 2, 3, and 4; and switches 1, 2, 3, and 4. Assuming that the voltage of cell 2 is too high and triggers the set single-cell passive balancing voltage differential threshold, the MCU or AFE controls the closing of switch 2 between cell 2 and cell 1. This controls the discharge of cell 2 through balancing resistor 2 to dissipate heat, thereby achieving passive balancing of cell 2 voltages. When the value of |cell2-cell1| meets the single-cell balancing voltage differential threshold, the MCU or AFE controls the opening of switch 2 between cell 2 and cell 1, ending passive balancing of cell 2.

[0053] This typical passive balancing solution for single cells dissipates the energy of cells with excessively high voltages as heat through heating of the balancing resistors. Due to the heat generation in the balancing resistor area of the BMS board, the balancing current of passive balancing is generally very small, often limited to less than 100mA. This results in slow balancing speeds and makes it difficult to meet balancing requirements in applications requiring high-power charging and discharging.

[0054] Furthermore, this method can only effectively execute this passive balancing strategy for cells with high cell voltages. For low cell voltages, the passive balancing strategy's execution logic is complex and difficult to implement. Furthermore, when two adjacent cells have high voltages, triggering the passive balancing threshold, this passive balancing strategy cannot simultaneously balance the two adjacent cells through the passive balancing resistors.

[0055] For the solution of active balancing of single cells, such as Figure 6 As shown in Figure 1, the typical single-cell active balancing circuit topology includes single cells Cell 1, Cell 12, Cell 3, and Cell 4, as well as a switch matrix circuit and a unidirectional switching power supply. Assuming that the voltage of cell 1 is low and triggers the set single-cell active balancing voltage differential threshold, the MCU or AFE controls the switch matrix to actively balance the charge of cell 1 through the high-voltage secondary side.

[0056] This typical single-cell active balancing solution can only balance a single cell at a time and cannot balance multiple cells simultaneously. Furthermore, this active charge balancing strategy can only be effectively executed in scenarios where the cell voltage is low, thereby achieving active balancing for all cells. In scenarios where a single cell voltage is high, this active balancing strategy cannot directly perform an active balancing discharge strategy on the cell with the high voltage.

[0057] To address this issue, a power balancing scheme is set for the energy storage component 10 in the related art. The battery cell power balancing scheme generally includes a single-cell active balancing strategy or a single-cell passive balancing strategy. Among them, the typical single-cell passive balancing strategy is to discharge and balance the battery cell 112 through the balancing resistor 130 when it is found that the voltage of a single cell is too high, thereby reducing the cell voltage of the single cell 112. This strategy completely consumes the energy of the battery cell 112 with excessively high voltage in the form of heat generated by the balancing resistor 130. Considering the heat problem, the balancing current of the passive balancing is very small, generally below 100mA, resulting in slow balancing efficiency. In application scenarios that require high-power charging and discharging, this balancing control method will appear to be very laborious, and consuming energy by generating heat through the balancing resistor 130 will lead to energy waste. At the same time, the passive balancing strategy can only be executed for scenarios with high single-cell voltages. When a scenario with low single-cell voltage occurs, the execution logic is complex and implementation is more difficult. When the voltages of two adjacent battery cells are both too high, the passive balancing strategy cannot achieve passive balancing of the two adjacent battery cells 112 by means of resistive heating at the same time due to heat dissipation requirements.

[0058] A typical single-cell active balancing strategy, when it detects that a cell 112 has a low voltage, will control the high-voltage secondary side to actively charge and balance the low-voltage cell 112. However, this balancing strategy can only balance one cell 112 at a time and cannot actively balance two or more cells 112 simultaneously. Furthermore, this method can only execute the active balancing strategy in scenarios where the voltage of a single cell is low. If the voltage of a single cell is high, the active balancing strategy cannot be directly executed on the cell 112 with the high voltage.

[0059] To this end, the embodiment of the present application combines active balancing and passive balancing in the energy storage component 10, and specifically sets up an active balancing module 12 and a passive balancing module 13. Among them, the active balancing module 12 includes a unidirectional flyback power supply 120 and a first switch matrix 122. The control module 14 controls the first switch matrix 122 to switch the switch state, and can actively charge and balance the battery cells 112 with lower cell voltages. The passive balancing module 13 includes a balancing resistor 130 and a second switch matrix 132. When the cell voltage of a single battery cell 112 is high, the control module 14 controls the second switch matrix 132 to switch the switch state, so that the energy of the single battery cell 112 with a high cell voltage can be released through the balancing resistor 130.

[0060] The active balancing module 12 and the passive balancing module 13 can perform balancing independently or simultaneously, thereby balancing multiple battery cells 112 at the same time.

[0061] In order to achieve the combination of active balancing and passive balancing, the present application sets a control module 14 to manage the operation of the active balancing module 12 and the passive balancing module 13. During operation, the control module 14 detects the cell voltage of each single cell 112 in real time and determines whether to select active balancing or passive balancing based on the detection results, or to start active balancing and passive balancing at the same time.

[0062] For example, when the voltage of one battery cell is too low and the voltage of another battery cell is too high, active balancing can be started for the battery cell with too low voltage, and passive balancing can be started for the battery cell with too high voltage, thereby effectively targeting the real scenario where both battery cells with too low voltage and too high voltage exist at the same time.

[0063] For example, energy storage module 11 includes four battery cells 112, designated cell 1, cell 2, cell 3, and cell 4. Cell 1 has a low voltage, while cell 3 has a high voltage. Active balancing module 12 performs charge balancing on cell 1, achieving active balancing. Meanwhile, passive balancing module 13 performs discharge balancing on cell 3, achieving passive balancing.

[0064] The energy storage assembly 10 of the present application is provided with both an active balancing module 12 and a passive balancing module 13 , so that the battery cells 112 with higher battery voltages and the battery cells 112 with lower battery voltages can be simultaneously balanced, thereby improving the battery cell 112 power balancing efficiency.

[0065] In some embodiments of the present application, optionally, the control module 14 includes: a controller 140, the controller 140 is communicatively connected to the unidirectional flyback power supply 120; an optocoupler drive module 142, the optocoupler drive module 142 is communicatively connected to the controller 140, and is also communicatively connected to the active balancing module 12; wherein, the controller 140 is used to control the unidirectional flyback power supply 120 to start working when the cell voltage of the first battery cell among the N battery cells 112 is less than the cell voltages of the other battery cells 112 among the N battery cells 112, and the difference between the cell voltage of the first battery cell and the cell voltages of the other battery cells 112 is greater than the active balancing threshold, and output an enable signal to the optocoupler drive module 142, so that the optocoupler drive module 142 controls the first switch unit 1220 electrically connected to the first battery cell to close, so as to charge and balance the first battery cell through the unidirectional flyback power supply 120.

[0066] In this embodiment, the control module 14 includes a controller 140 and an optocoupler driver module 142. The controller 140 may be an MCU (Micro Controller Unit). The optocoupler driver module 142, as a digital isolation module, enables digital signal transmission between the weak-current MCU circuit and the strong-current energy storage circuit, and achieves digital isolation between the input and output sides.

[0067] Among them, when the cell voltage of the first battery cell is lower than the cell voltage of the other battery cells 112, and the voltage difference between the cell voltage of the first battery cell and the cell voltage of the other battery cells 112 exceeds the set active balancing threshold, the controller 140 starts to actively charge and balance the first battery cell. At this time, the controller 140 controls the unidirectional flyback power supply 120 to start working, and outputs an enable signal to the optocoupler drive module 142. When the optocoupler drive module 142 receives the enable signal, it controls the first switch unit 1220 connected to the first battery cell to close. At this time, the charging circuit between the first battery cell and the unidirectional flyback power supply 120 is connected, and the unidirectional flyback power supply 120 starts to charge and balance the first battery cell, thereby increasing the cell voltage of the first battery cell and achieving active balancing.

[0068] By setting up an optocoupler driving module 142, the present application can achieve signal isolation between the MCU side and the energy storage circuit side, block common-mode interference and ground loop current, and improve system safety and anti-interference capabilities.

[0069] In some embodiments of the present application, optionally, the control module 14 also includes: an analog front-end module 144, the analog front-end module 144 is electrically connected to the N battery cells 112, and is communicatively connected to the controller 140, and the analog front-end module 144 is used to collect the battery cell voltage of each battery cell 112; wherein, when the battery cell voltage of the second battery cell among the N battery cells 112 is greater than the battery cell voltages of the other battery cells 112 among the N battery cells 112, and the difference between the battery cell voltage of the second battery cell and the battery cell voltages of the other battery cells 112 is greater than the passive balancing threshold, the analog front-end module 144 controls the second switch unit 1320 electrically connected to the second battery cell to close, so as to discharge and balance the second battery cell through the balancing resistor 130.

[0070] In this embodiment, the control module 14 of the energy storage component 10 also includes an analog front-end (AFE) module. The AFE module is capable of collecting the cell voltage of each individual cell 112 and sending the collected cell voltage to the controller 140. When the analog front-end module 144 collects that the cell voltage of the second cell is higher than the cell voltage of the other cells 112, and the voltage difference between the cell voltage of the second cell and the cell voltage of the other cells 112 exceeds the set passive balancing threshold, the second switch unit 1320 electrically connected to the second cell is controlled to be closed. At this time, the discharge circuit between the second cell and the balancing resistor 130 is turned on, and the second cell will release current to the balancing resistor 130. This part of the current can form Joule heat on the balancing resistor 130, thereby consuming part of the energy and achieving passive balancing of the second cell.

[0071] For example, Figure 2 As shown, it is assumed that there are four cells 112 in the energy storage component 10, which are respectively labeled cell 1, cell 2, cell 3, and cell 4. The AFE module collects the cell voltages of each cell 112 in real time, which are 2.8V, 3.3V, 3.7V, and 3.3V, respectively, and transmits them to the MCU in real time. When the MCU detects that the cell voltage of cell 3 is too high at 3.7V, and the voltage difference between the cell voltage of cell 3 and the voltage of other cells exceeds the passive balancing threshold of 0.3V, the MCU sends a command to the AFE module. The AFE module outputs a high level of 3.3V to the GS pole of NMOS3, driving the DS pole of NMOS3 to turn on. The voltage across resistor R3 is divided by 1.6V, and the SG pole of PMOS3, which is electrically connected to cell 3, is divided. The SD pole of PMOS3 is turned on, and cell 3 forms a loop through the SD pole of PMOS3 and the balancing resistor R3. The balancing resistor R3 continues to heat up and passively discharges and balances the cell 3 monomer.

[0072] Afterwards, the AEF module collects the cell voltage of cell 3 in real time and transmits it to the MCU. When the MCU detects that the voltage difference between cell 3 and the cell voltages of other cells 112 is less than or equal to the 0.1V threshold for stopping passive balancing, the MCU sends a command to the AFE module, which outputs a low level of 0V to the GS pole of NMOS3. The DS pole of NMOS3 is disconnected, and there is no voltage divider on both sides of resistor R3, that is, there is no voltage divider on the SG pole of PMOS3. The SD pole of PMOS3 is disconnected, and the passive discharge balancing circuit of cell 3 is disconnected, and passive balancing stops.

[0073] The present application uses an analog front-end module 144 to collect the cell voltage of a single battery cell 112. When the cell voltage of the second battery cell is too high, the second switch unit 1320 is controlled to close to conduct the discharge circuit between the second battery cell and the balancing resistor 130, thereby achieving passive discharge balancing of the battery cell 112 with too high cell voltage.

[0074] In some embodiments of the present application, optionally, the optocoupler driving module 142 includes N digital isolation optocouplers 1422, and the N digital isolation optocouplers 1422 are electrically connected to the control ends of the N first switch units 1220 respectively, and the digital isolation optocouplers 1422 are used to control the first switch unit 1220 to close or open.

[0075] In this embodiment, the optocoupler driver module 142 is specifically provided with N digital isolation optocouplers 1422 corresponding one to one with the N battery cells 112. Each digital isolation optocoupler 1422 is electrically connected to a first switch unit 1220 and is used to control the closing or opening of a first switch unit 1220.

[0076] For example, Figure 2 As shown, assume that there are four cells 112 in the energy storage assembly 10, designated cell 1, cell 2, cell 3, and cell 4. The AFE module collects the cell voltages of each cell 112 in real time, which are 2.8V, 3.3V, 3.7V, and 3.3V, respectively, and transmits them to the MCU in real time. When the MCU detects that the cell voltage of cell 1 is too low at 2.8V, and the voltage difference between cell 1 and the other cell voltages exceeds the active balancing threshold of 0.3V, the MCU's EN5 pin outputs a high voltage of 3.3V, driving the unidirectional flyback power supply 120 to begin operation. The MCU's EN1 pin outputs a high voltage of 3.3V to the light-emitting diode side of optocoupler 1, turning on the CE terminal of optocoupler 1. The E terminal outputs a high voltage of 5V, driving the NMOS 1 on the voltage output side of cell 1 to close. Cell 1 is then connected to the input side of the unidirectional flyback power supply 120 module, and the unidirectional flyback power supply 120 module begins charging and balancing cell 1.

[0077] At the same time, the AFE module monitors the cell voltage of cell 1 in real time and transmits it to the MCU. When the MCU detects that the voltage difference between cell 1 and the voltages of other cells 112 is less than or equal to the 0.1V threshold for stopping active balancing, the MCU first drives the unidirectional flyback power supply 120 to stop operating. The MCU's EN1 pin then outputs a low level of 0V, the light-emitting diode of optocoupler 1 turns off, the CE terminal of optocoupler 1 disconnects, the E side of optocoupler 1 outputs a low level of 0V, NMOS 1 disconnects, and active balancing stops.

[0078] The present application provides an independent digital isolation optocoupler 1422 to perform active charge balancing control on each individual battery cell 112 , thereby improving system safety and reliability, and enhancing the system's anti-interference capability.

[0079] In some embodiments of the present application, optionally, the energy storage assembly 10 further includes: a power supply module 15 , which is electrically connected to the optocoupler driving module 142 , and is used to supply power to the optocoupler driving module 142 .

[0080] In this embodiment, the energy storage assembly 10 includes a power supply module 15, which can power the optocoupler driver module 142, specifically each digital isolation optocoupler 1422 in the optocoupler driver module 142. Exemplarily, the power supply module 15 is a DC power supply module 15.

[0081] In some embodiments of the present application, optionally, the first switching unit 1220 includes: a first sub-switch device 1222, wherein the first end of the first sub-switch device 1222 is electrically connected to the positive pole of the unidirectional flyback power supply 120, and the second end of the first sub-switch device 1222 is electrically connected to the positive pole of the battery cell 112; a second sub-switch device 1224, wherein the second end of the second sub-switch device 1224 is electrically connected to the negative pole of the unidirectional flyback power supply 120, and the second end of the second sub-switch device 1224 is electrically connected to the negative pole of the battery cell 112; wherein the switching states of the first sub-switch device 1222 and the second sub-switch device 1224 are the same.

[0082] In this embodiment, the first switching unit 1220 includes a first sub-switching device 1222 and a second sub-switching device 1224. The first sub-switching device 1222 is connected to the positive electrode of the unidirectional flyback power supply 120 and the positive electrode of the battery cell 112, respectively. The second sub-switching device 1224 is connected to the negative electrode of the unidirectional flyback power supply 120 and the negative electrode of the battery cell 112, respectively. When the first sub-switching device 1222 is closed, the positive electrode of the unidirectional flyback power supply 120 is connected to the positive electrode of the battery cell 112. When the second sub-switching device 1224 is closed, the negative electrode of the unidirectional flyback power supply 120 is connected to the negative electrode of the battery cell 112. The charging circuit between the unidirectional flyback power supply 120 and the battery cell 112 is conductive only when both the first sub-switching device 1222 and the second sub-switching device 1224 are closed.

[0083] The present application can improve the reliability of the active balancing module 12 by separately providing the first sub-switch device 1222 and the second sub-switch device 1224 .

[0084] In some embodiments of the present application, optionally, the first sub-switching device 1222 and the second sub-switching device 1224 are both N-type metal-oxide-semiconductor transistors.

[0085] In this embodiment, both the first sub-switch device 1222 and the second sub-switch device 1224 are N-type metal-oxide-semiconductor (NMOS) transistors. Active balancing of the battery cells 112 with lower cell voltages is achieved through the first switch matrix 122, which is composed of the controller 140, the optocoupler driver module 142, the unidirectional flyback power supply 120, and the NMOS. This simple implementation logic solves the problem of relatively complex execution logic in scenarios where the cell voltage of a single battery cell 112 is low.

[0086] In some embodiments of the present application, optionally, the second switch unit 1320 is a P-type metal-oxide-semiconductor transistor.

[0087] In this embodiment, the second switch unit 1320 is a P-Meta-Oxied-Semiconductor (PMOS) transistor. By controlling the second switch matrix 132 composed of PMOS by the AFE module and combining the passive balancing strategy of heating the balancing resistor 130, efficient discharge and heating balancing of the battery cell 112 can be achieved. By combining the passive balancing control method of the second switch matrix composed of PMOS by the AFE module and the active balancing control method of the first switch matrix 122 composed of the controller 140, the optocoupler driver module 142, the unidirectional flyback power supply 120 and the NMOS, the second battery cell with an overly high battery cell voltage and the first battery cell with an overly low battery cell voltage can be balanced at the same time, thereby improving the balancing efficiency of the battery cell 112.

[0088] In some embodiments of the present application, a method for balancing control of an energy storage assembly is provided, and the method is executed by the energy storage assembly provided in any of the above embodiments. Figure 3 A flow chart showing a method for balancing control of energy storage components according to some embodiments of the present application is shown. Figure 3 As shown, the balancing control method includes:

[0089] Step 302, obtaining the cell voltage of each cell in the N cells;

[0090] Step 304 : performing active charge balancing and / or passive discharge balancing on the N battery cells according to the battery cell voltages.

[0091] In this embodiment, active balancing and passive balancing are combined in the energy storage component, and active balancing modules and passive balancing modules are set up specifically. Among them, the active balancing module includes a unidirectional flyback power supply and a first switch matrix. The control module controls the switching state of the first switch matrix to actively charge and balance the battery cells with lower cell voltages. The passive balancing module includes a balancing resistor and a second switch matrix. When the cell voltage of a single cell is high, the control module controls the switching state of the second switch matrix to enable the energy of the single cell with a high cell voltage to be released through the balancing resistor.

[0092] Among them, the active balancing module and the passive balancing module can balance independently or work simultaneously, thereby balancing multiple battery cells at the same time.

[0093] For example, an energy storage module includes four cells, designated cell 1, cell 2, cell 3, and cell 4. Cell 1's voltage is low, while cell 3's voltage is high. The active balancing module performs charge balancing on cell 1, achieving active charge balancing. Simultaneously, the passive balancing module performs discharge balancing on cell 3, achieving passive discharge balancing.

[0094] The energy storage assembly of the present application is provided with both an active balancing module and a passive balancing module, so that the battery cells with higher battery voltages and the battery cells with lower battery voltages can be simultaneously balanced, thereby improving the battery cell balance efficiency.

[0095] In some embodiments of the present application, optionally, the energy storage component includes a unidirectional flyback power supply, which actively charges and balances N battery cells according to the battery cell voltage, including: when the battery cell voltage of a first battery cell among the N battery cells is less than the battery cell voltage of other battery cells among the N battery cells, and the difference between the battery cell voltage of the first battery cell and the battery cell voltage of the other battery cells is greater than the active balancing threshold, controlling the unidirectional flyback power supply to start working, and controlling the first switch unit electrically connected to the first battery cell to close, so as to charge and balance the first battery cell through the unidirectional flyback power supply.

[0096] In this embodiment, when the cell voltage of the first battery cell is lower than the cell voltage of other battery cells, and the voltage difference between the cell voltage of the first battery cell and the cell voltage of other battery cells exceeds the set active balancing threshold, the controller starts to actively charge and balance the first battery cell. At this time, the controller controls the unidirectional flyback power supply to start working and outputs an enable signal to the optocoupler drive module. When the optocoupler drive module receives the enable signal, it controls the first switch unit connected to the first battery cell to close. At this time, the charging circuit between the first battery cell and the unidirectional flyback power supply is connected, and the unidirectional flyback power supply starts to charge and balance the first battery cell, thereby increasing the cell voltage of the first battery cell and achieving active balancing.

[0097] In some embodiments of the present application, optionally, passive discharge balancing is performed on N battery cells based on the battery cell voltage, including: when the battery cell voltage of the second battery cell among the N battery cells is greater than the battery cell voltages of the other battery cells among the N battery cells, and the difference between the battery cell voltage of the second battery cell and the battery cell voltages of the other battery cells is greater than the passive balancing threshold, controlling the second switch unit electrically connected to the second battery cell to close, so as to discharge balance the second battery cell through the balancing resistor.

[0098] In this embodiment, when the cell voltage of the second battery cell is higher than the cell voltage of other battery cells, and the voltage difference between the cell voltage of the second battery cell and the cell voltage of other battery cells exceeds the set passive balancing threshold, the second switch unit electrically connected to the second battery cell is controlled to close. At this time, the discharge loop between the second battery cell and the balancing resistor is turned on, and the second battery cell will release current to the balancing resistor. This part of the current can form Joule heat on the balancing resistor, thereby consuming part of the energy and achieving passive balancing of the second battery cell.

[0099] In some embodiments of the present application, a balancing control device for an energy storage assembly is provided, which is applied to the energy storage assembly provided in any of the above embodiments. Figure 4 The structural block diagram of the balancing control device of the energy storage assembly of some embodiments of the present application is shown as follows: Figure 4 As shown, the balancing control device 400 includes: an acquisition module 402 for acquiring the cell voltage of each of the N battery cells; and a balancing module 404 for performing active charge balancing and / or passive discharge balancing on the N battery cells according to the cell voltage.

[0100] In this embodiment, active balancing and passive balancing are combined in the energy storage component, and active balancing modules and passive balancing modules are set up specifically. Among them, the active balancing module includes a unidirectional flyback power supply and a first switch matrix. The control module controls the switching state of the first switch matrix to actively charge and balance the battery cells with lower cell voltages. The passive balancing module includes a balancing resistor and a second switch matrix. When the cell voltage of a single cell is high, the control module controls the switching state of the second switch matrix to enable the energy of the single cell with a high cell voltage to be released through the balancing resistor.

[0101] Among them, the active balancing module and the passive balancing module can balance independently or work simultaneously, thereby balancing multiple battery cells at the same time.

[0102] For example, an energy storage module includes four cells, designated cell 1, cell 2, cell 3, and cell 4. Cell 1's voltage is low, while cell 3's voltage is high. The active balancing module performs charge balancing on cell 1, achieving active charge balancing. Simultaneously, the passive balancing module performs discharge balancing on cell 3, achieving passive discharge balancing.

[0103] The energy storage assembly of the present application is provided with both an active balancing module and a passive balancing module, so that the battery cells with higher battery voltages and the battery cells with lower battery voltages can be simultaneously balanced, thereby improving the battery cell balance efficiency.

[0104] In some embodiments of the present application, a readable storage medium is provided on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the balancing control method provided in any of the above embodiments are implemented, and thus the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0105] In some embodiments of the present application, an energy storage system is provided, including: a battery module, including multiple battery cells; a battery management system, including an energy storage component as provided in any of the above embodiments, which performs balanced control of the power of multiple battery cells in the battery module based on the energy storage component; and / or executes the balanced control method proposed in any of the above embodiments, thereby achieving the same technical effect. To avoid repetition, it will not be described here.

[0106] The methods may be implemented in various ways depending on the specific features and / or example applications. For example, the methods may be implemented through a combination of hardware, firmware, and / or software. For example, in a hardware implementation, the processor may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, electronic devices, other equipment units for performing the above functions, and / or combinations thereof.

[0107] A computer-readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. A computer-readable storage medium may be, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. A non-exhaustive list of more specific examples of computer-readable storage media includes: a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM) or flash memory, a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory card, a floppy disk, an encoding mechanical device (such as a punched card or a groove having a raised structure with instructions recorded thereon), and any suitable combination of the above. The computer-readable storage medium used herein should not be understood as a transmission signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagated through waveguides or other transmission media, or electrical signals transmitted through wires.

[0108] In the description of this application, the term "plurality" refers to two or more, unless otherwise expressly defined. The orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship described in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application; the terms "connect", "install", "fixed", etc. 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0109] In the description of this application, the terms "one embodiment," "some embodiments," "specific embodiments," etc., 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 this application. In this application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in any one or more embodiments or examples.

[0110] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An energy storage component, characterized in that: include: An energy storage module, wherein the energy storage module includes N battery cells, where N is a positive integer greater than 1; An active balancing module, the active balancing module comprising: Unidirectional flyback power supply; a first switch matrix, the first switch matrix comprising N first switch units, wherein a first end of each of the N first switch units is electrically connected to the unidirectional flyback power supply, and a second end of each of the N first switch units is electrically connected to the N battery cells; A passive balancing module, the passive balancing module comprising: N balancing resistors; a second switch matrix, the second switch matrix comprising N second switch units; wherein each of the N balancing resistors is electrically connected to a corresponding battery cell through a corresponding second switch unit; A control module is electrically connected to the battery cells, the active balancing module, and the passive balancing module. The control module is used to control the active balancing module to actively charge and balance the N battery cells according to the battery cell voltages of the N battery cells; and / or control the passive balancing module to passively discharge and balance the N battery cells.

2. The energy storage assembly according to claim 1, characterized in that The control module includes: A controller, the controller being communicatively connected to the unidirectional flyback power supply; an optical coupler driving module, the optical coupler driving module being communicatively connected to the controller and to the active balancing module; Wherein, the controller is used to control the unidirectional flyback power supply to start working when the cell voltage of the first cell among the N cell is lower than the cell voltage of the other cell among the N cell, and the difference between the cell voltage of the first cell and the cell voltage of the other cell is greater than the active balancing threshold, and output an enable signal to the optocoupler drive module so that the optocoupler drive module controls the first switch unit electrically connected to the first cell to close, so as to charge and balance the first cell through the unidirectional flyback power supply.

3. The energy storage assembly according to claim 2, characterized in that: The control module further includes: An analog front-end module, the analog front-end module is electrically connected to the N battery cells and is in communication with the controller, and the analog front-end module is used to collect the battery cell voltage of each battery cell; Among them, when the cell voltage of the second battery cell among the N battery cells is greater than the cell voltages of the other battery cells among the N battery cells, and the difference between the cell voltage of the second battery cell and the cell voltage of the other battery cells is greater than the passive balancing threshold, the analog front-end module controls the second switch unit electrically connected to the second battery cell to close, so as to discharge and balance the second battery cell through the balancing resistor.

4. The energy storage assembly according to claim 2, characterized in that The optocoupler driving module includes N digital isolation optocouplers, which are electrically connected to the control ends of the N first switch units respectively. The digital isolation optocouplers are used to control the first switch units to be closed or opened.

5. The energy storage assembly according to claim 2, characterized in that: Also includes: A power supply module is electrically connected to the optocoupler driving module and is used to supply power to the optocoupler driving module.

6. The energy storage assembly according to any one of claims 1 to 5, characterized in that: The first switch unit includes: a first sub-switching device, wherein a first end of the first sub-switching device is electrically connected to the positive electrode of the unidirectional flyback power supply, and a second end of the first sub-switching device is electrically connected to the positive electrode of the battery cell; a second sub-switching device, wherein the second end of the second sub-switching device is electrically connected to the negative electrode of the unidirectional flyback power supply, and the second end of the second sub-switching device is electrically connected to the negative electrode of the battery cell; The switching states of the first sub-switching device and the second sub-switching device are the same.

7. The energy storage assembly according to claim 6, characterized in that: The first sub-switching device and the second sub-switching device are both N-type metal-oxide-semiconductor transistors.

8. The energy storage assembly according to any one of claims 1 to 5, characterized in that: The second switch unit is a P-type metal-oxide-semiconductor transistor.

9. A method for balancing control of an energy storage component, characterized in that: The balancing control method is performed by the energy storage assembly according to any one of claims 1 to 8, and the balancing control method includes: Obtaining the cell voltage of each of the N cell; Active charge balancing and / or passive discharge balancing are performed on the N battery cells according to the battery cell voltages.

10. The balancing control method according to claim 9, characterized in that: The energy storage component includes a unidirectional flyback power supply, and the active charging and balancing of the N battery cells according to the battery cell voltage includes: When the cell voltage of a first cell among the N cell cells is lower than the cell voltages of the other cell cells among the N cell cells, and the difference between the cell voltage of the first cell and the cell voltages of the other cell cells is greater than the active balancing threshold, the unidirectional flyback power supply is controlled to start working, and the first switch unit electrically connected to the first cell is controlled to close, so as to charge and balance the first cell through the unidirectional flyback power supply.

11. The balancing control method according to claim 9, wherein: The passive discharge balancing of the N battery cells according to the battery cell voltages includes: When the cell voltage of the second battery cell among the N battery cells is greater than the cell voltages of the other battery cells among the N battery cells, and the difference between the cell voltage of the second battery cell and the cell voltages of the other battery cells is greater than the passive balancing threshold, the second switch unit electrically connected to the second battery cell is controlled to be closed to discharge and balance the second battery cell through the balancing resistor.

12. A balancing control device for an energy storage component, characterized in that: Applicable to the energy storage assembly according to any one of claims 1 to 8, the balancing control device comprises: An acquisition module, configured to acquire a cell voltage of each of the N cell; The balancing module is used to perform active charge balancing and / or passive discharge balancing on the N battery cells according to the battery cell voltages.

13. An energy storage system, characterized in that: include: A battery module, including multiple battery cells; A battery management system comprising the energy storage component according to any one of claims 1 to 8, which performs balanced control of the power of the multiple battery cells in the battery module based on the energy storage component; and / or Execute the balancing control method according to any one of claims 9 to 11.

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