Active equalization control device

Abstract

The embodiment of the utility model provides an active equalization control device, and relates to the technical field of batteries. The device comprises a control end and an execution end, the control end comprises a control chip, and the control chip is connected with the execution end through an optocoupler; the execution end comprises a charging power supply, at least three battery cells and an MOS (Metal Oxide Semiconductor) tube control circuit, the adjacent battery cells are connected in series, and the control chip is respectively connected with two poles of each battery cell through a chip interface; the MOS tube control circuit comprises a left arm bridge connected with the positive electrode of each battery cell and a right arm bridge connected with the negative electrode of each battery cell, the left arm bridge and the right arm bridge respectively comprise an MOS tube and a diode which are connected in series, the source electrode of the MOS tube is connected with the positive electrode of the diode, and the base electrode of the MOS tube is connected with the optocoupler. According to the method provided by the invention, the problems of easy element damage and insufficient safety when the cell connector is connected to the loop communicated with the charging power supply in the prior art are effectively solved.

Description

Active equalization control device Technical Field

[0001] This application relates to the field of battery technology, and in particular to an active balancing control device. Background Technology

[0002] In the field of new energy vehicle technology, a battery management system (BMS) is used to control the charging process of battery cells in the vehicle to ensure the efficiency and safety of the charging process. In order to ensure the monitoring and adaptation of different charging progress and charging status of each cell during the charging process, active equalization control of the cell charging process is performed by combining analog front-end (AFE) and MOSFET control elements.

[0003] In related technologies, during the active balancing control process, when the battery cell connector is connected to the circuit where the charging power supply is located, control components such as MOSFETs are prone to damage due to instantaneous voltage breakdown or short circuits in the corresponding branches, resulting in insufficient overall equipment safety. Summary of the Invention

[0004] This application provides an active balancing control device to solve the problem in related technologies where component damage and insufficient safety are prone to occur when the battery cell connector is connected to a circuit connected to the charging power supply.

[0005] In a first aspect, this application provides an active equalization control device, comprising:

[0006] Control end and execution end,

[0007] The control unit includes a control chip, which is connected to the execution unit via an optocoupler;

[0008] The execution end includes a charging power supply, battery cells, and MOSFET control circuitry. There are at least three battery cells, with adjacent cells connected in series. The control chip is connected to the two poles of each battery cell through a chip interface.

[0009] The MOSFET control circuit includes a left-hand bridge connected to the positive terminal of each battery cell and a right-hand bridge connected to the negative terminal of each battery cell. The left-hand bridge and the right-hand bridge each include a MOSFET and a diode connected in series. The source of the MOSFET is connected to the positive terminal of the diode, and the base of the MOSFET is connected to the optocoupler. The drain of the MOSFET in the left-hand bridge is connected to the positive terminal of the charging power supply, and the drain of the MOSFET in the right-hand bridge is connected to the negative terminal of the battery cell.

[0010] The negative terminal of the diode in the left arm bridge is connected to the positive terminal of the battery cell, and the negative terminal of the diode in the right arm bridge is connected to the negative terminal of the charging power supply. A safety capacitor and a safety resistor are connected in parallel between the source and gate of the MOSFET, and the safety capacitor and the safety resistor are connected in parallel with each other.

[0011] In one embodiment of this disclosure, the optocoupler includes an input terminal and an output terminal. The input terminal is a light-emitting diode disposed at the control terminal, and the output terminal is a photoresistor disposed at the execution terminal.

[0012] In one embodiment of this disclosure, the negative terminal of the light-emitting diode is connected to the chip interface of the control chip, the positive terminal of the light-emitting diode is connected to the positive and negative terminals of two adjacent cells respectively, one end of the photoresistor is connected to the constant current power supply, and the other end of the photoresistor is connected to the base of the MOS transistor in the left and right arm bridges respectively.

[0013] In one embodiment of this disclosure, the bases of the MOSFETs in the left and right arm bridges are connected to a photoresistor via diodes, the base of the MOSFET in the left arm bridge is connected to the negative terminal of the corresponding diode, and the base of the MOSFET in the right arm bridge is connected to the negative terminal of the corresponding diode.

[0014] In one embodiment of this disclosure, a resistor is provided between the base of the MOS transistor and the negative terminal of the corresponding diode.

[0015] In one embodiment of this disclosure, the control chip is connected to the two poles of each battery cell via a diode and a resistor through a chip interface; the positive pole of the battery cell is connected to the positive pole of the adjacent diode, and the chip interface is connected in series with the negative pole of the adjacent diode through a resistor.

[0016] In one embodiment of this disclosure, a transistor is connected in parallel between the positive and negative terminals of the battery cell. The base of the transistor is connected to the chip interface through a resistor, the collector of the transistor is connected to the negative terminal of the light-emitting diode of the optocoupler, the positive terminal of the light-emitting diode is connected to the positive terminal of the battery cell through a resistor, and the emitter of the transistor is connected to the negative terminal of the battery cell.

[0017] In one embodiment of this disclosure, the positive terminal of the battery cell is grounded via a capacitor.

[0018] In one embodiment of this disclosure, a capacitor is connected in parallel between the base and emitter of the transistor, the base of the transistor is connected to the negative terminal of an adjacent diode, and the emitter of the transistor is connected to the positive terminal of an adjacent diode.

[0019] In one embodiment of this disclosure, a capacitor is connected between the positive and negative terminals of the battery cell and the corresponding chip interface, and the two ends of the capacitor are connected to the negative terminal of an adjacent diode through a resistor.

[0020] The active balancing control device provided in this embodiment uses a control chip connected to an optocoupler. The control chip sends control signals to a MOSFET via the optocoupler to control the MOSFET's conduction state, thereby controlling whether the battery cell is connected to the charging power supply. Once the battery cell is connected, the control chip monitors voltage changes across the battery cell to determine its charging status, thus achieving active balancing control during charging. Simultaneously, by connecting a capacitor and a resistor in parallel with the MOSFET, the impact of instantaneous voltage on the MOSFET is reduced when the battery cell is connected to the power supply, ensuring the safety of the MOSFET structure and consequently the safety of the entire circuit and the lifespan of the device. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] Figure 1 is an application scenario diagram of the active equalization control device provided in the embodiments of this disclosure;

[0023] Figure 2 is a schematic diagram of the structure of an active equalization control device provided in an embodiment of this disclosure;

[0024] Figure 3 is a schematic diagram of the control terminal structure of an active balancing control device provided in another embodiment of this disclosure.

[0025] Among them, 100 is the battery management module, 111 is the control module, and 120 is the phase-connected optocoupler;

[0026] 200. Active balancing control device;

[0027] 210. Control terminal; 211. Control chip; 212. Chip interface; 213. Control switch; 220. Optocoupler; 221. Input terminal; 222. Output terminal; 223. Constant current power supply; 224. Adjacent diode; 225. Light-emitting diode; 226. Photoresistor.

[0028] 300, Execution end; 310, Charging power supply; 320, Battery cell; 330, MOSFET control circuit; 331, Left arm bridge; 332, Right arm bridge; 333, Safety capacitor; 334, Safety resistor.

[0029] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0031] In the field of new energy vehicle technology, the Battery Management System (BMS) is a key component ensuring the safe and efficient operation of vehicle batteries. The BMS improves charging efficiency and ensures safety by monitoring and controlling the charging process of battery cells. Specifically, to ensure the monitoring and adaptation of different charging progress and states of each cell during the charging process, analog front-end (AFE) and MOSFET control elements are used to actively sample the voltage in the charging circuit. Based on the voltage of each cell, the corresponding charging state is controlled, thereby achieving active balancing control of the charging process. Circuits based on active balancing control typically connect the charging power supply and the cell through MOSFETs to control the conduction of the circuit containing the cell, thus controlling the charging state of the cell.

[0032] During active balancing control, when the cell connector is connected to a circuit connected to the charging power supply, the control terminal voltage of the parasitic capacitor connected in parallel with the MOSFET in the branch connected to the cell may exceed the turn-on voltage and break down, causing a short circuit between the gate and source of the MOSFET. This can lead to a false short circuit in the circuit connected to the cell, which can easily damage the components.

[0033] As a critical switching element in a circuit, the parasitic capacitance of a MOSFET can induce unwanted current paths during high-speed switching, leading to short circuits or even component damage. The challenge lies in handling MOSFET false turn-on without affecting charging efficiency or circuit complexity. Traditional solutions often require additional protection circuitry, which not only increases system complexity but may also reduce overall efficiency.

[0034] The active balancing control device provided in this application achieves signal isolation and accurate transmission by setting up a control terminal and an execution terminal, with the control terminal connected to the execution terminal via an optocoupler. The execution terminal includes a charging power supply, battery cell, and MOSFET control circuitry, with a safety capacitor and a safety resistor connected in parallel between the source and gate of the MOSFET to prevent accidental short circuits. This ensures the safety and reliability of the charging process while maintaining the simplicity and efficiency of the circuit.

[0035] Figure 1 is a schematic diagram of the application scenario of the active balancing control device provided in this application. As shown in Figure 1, in the active balancing control process of the prior art, in the battery management module 100, the control module 110 controls the state of the connected optocoupler 120, thereby controlling when the battery cell U0 to be charged starts charging and when it stops charging. When there are multiple battery cells to be charged, the active balancing control process is realized by controlling the charging state of each battery cell.

[0036] It should be noted that the scenario shown in Figure 1 includes a battery management module, a control module, a connected optocoupler, and a battery cell to be charged, which are only used as examples of one or a specific number. However, this disclosure is not limited to this. That is to say, the number of battery management modules, control modules, connected optocouplers, and battery cells to be charged can be arbitrary.

[0037] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0038] Figure 2 is a schematic diagram of the active balancing control device provided in this application. As shown in Figure 2, the device includes:

[0039] Control terminal 210 and execution terminal 300,

[0040] The control terminal 210 includes interconnected control chips 211, which are connected to the execution terminal 300 via optocouplers 220.

[0041] The execution end 300 includes a charging power supply 310, a battery cell 320 and a MOSFET control circuit 330. There are at least three battery cells 320, and adjacent battery cells 320 are connected in series with each other. The control chip 211 is connected to the two poles of each battery cell 320 through the chip interface 212.

[0042] The MOSFET control circuit 330 includes a left arm bridge 331 connected to the positive terminal of each battery cell 320 and a right arm bridge 332 connected to the negative terminal of each battery cell 320. The left arm bridge 331 and the right arm bridge 332 each include a MOSFET and a diode connected in series. The source of the MOSFET is connected to the positive terminal of the diode, and the base of the MOSFET is connected to the optocoupler 220. The drain of the MOSFET in the left arm bridge 331 is connected to the positive terminal of the charging power supply 310, and the drain of the MOSFET in the right arm bridge 332 is connected to the negative terminal of the battery cell 320.

[0043] The negative terminal of the diode in the left arm bridge 331 is connected to the positive terminal of the battery cell 320, and the negative terminal of the diode in the right arm bridge 332 is connected to the negative terminal of the charging power supply 310. A safety capacitor 333 and a safety resistor 334 are connected in parallel between the source and gate of the MOSFET, and the safety capacitor 333 and the safety resistor 334 are connected in parallel with each other.

[0044] Specifically, Figure 2 mainly shows the execution end, while Figure 3 is a structural diagram of the control end. Therefore, the execution end in Figure 2 shows the control chip 211 and its specific connections. For example, combining Figures 2 and 3, one end of VC1 in Figure 2 is connected to the positive terminal of U1, and the other end in Figure 3 is connected to the adjacent diode indicated by label 224. The connection between S2 and VC2 is only shown as LED 225 in Figure 2, while in Figure 3, the specific connection includes components such as resistors, diodes, transistors, and capacitors. The relevant structural connections can be referred to in the above example, which will be further described below.

[0045] In this scheme, the control terminal 210 is used to achieve active balancing control by outputting control signals during the charging process of the battery cell 320. The control chip 211 can be a control unit (BCU) in the battery management system (BMS), a separate microcontroller unit (MCU), or a combination of an analog front end (AFE) and a control unit. The analog front end is usually used to monitor the voltage of the battery cell 320 and transmit the monitoring results to the control unit so that the control unit can generate control commands based on the processing of the monitoring results (i.e., send electrical signals of different levels to the MOSFET through the optocoupler 220 to control the conduction state of the MOSFET, thereby connecting or disconnecting the battery cell 320 from the circuit where the charging power supply 310 is located), thereby achieving the effect of active balancing control.

[0046] The function of optocoupler 220 is to transmit control commands between the control terminal 210 and the execution terminal 300, and to achieve electrical isolation of the signals, ensuring that the control signals are not affected by external interference during transmission, while avoiding the influence of excessively high voltage values ​​at the execution terminal 300 on the control chip 211, thereby improving the safety and reliability of the system.

[0047] The actuator 300 controls whether the battery cell 320 is connected to the circuit corresponding to the charging power supply 310 according to the control command sent by the controller 210. There are at least three battery cells 320, and adjacent battery cells 320 are connected in series. This series structure helps to increase the total voltage of the battery pack and is suitable for high-voltage applications, such as battery packs for new energy vehicles.

[0048] The control chip 211 is connected to the two poles of each cell 320, thereby enabling the simulation control chip 211 to monitor the voltage of each cell 320 to determine the charging state of the cell 320, and then to achieve active equalization control based on the charging state.

[0049] There is usually only one control chip 211, but it has multiple interfaces. For example, it can be connected to the optocoupler 220 corresponding to each battery cell 320 through each chip interface 212 (S1, S2, S3, and S4 in Figure 2 represent chip interfaces). Alternatively, it can be connected to the optocoupler 220 corresponding to each chip 320 through a structure such as a multiplexer switch to complete the corresponding signal transmission.

[0050] The MOS transistor control circuit 330 consists of a left arm bridge 331 and a right arm bridge 332 (Figure 2 shows three cells U1, U2, and U3; only the left arm bridge 331 and right arm bridge 332 corresponding to U3 are shown in the figure, but U1 and U2 also have corresponding structures, and these structures have the same relative positions, connections, and composition, so they are not marked repeatedly). These structures are connected to the positive and negative terminals of the cell 320, respectively. The cell 320 is connected to the charging power supply 310 through the left and right arm bridges (in actual applications, the charging power supply 310 can also be combined with rectifier circuits, filter circuits, amplifiers, etc. In this scheme, it is not the focus of protection, so it is only simplified). When the left and right arm bridges are turned on according to the instructions of the control chip 211, a charging circuit can be formed between the cell 320 and the charging power supply 310, realizing the charging process of the cell 320.

[0051] The left arm bridge 331 and the right arm bridge 332 each include a MOSFET and a diode connected in series. The source of the MOSFET is connected to the anode of the diode, and the base is connected to the output of the optocoupler 220 to receive control commands sent by the control terminal 210 and switch the conduction state of the MOSFET according to the control commands.

[0052] The drain of the MOSFET in the left arm bridge 331 is connected to the positive terminal of the charging power supply 310, while the drain of the MOSFET in the right arm bridge 332 is connected to the negative terminal of the battery cell 320, so that when the MOSFET is turned on, the battery cell 320 and the charging power supply 310 form a power-on circuit.

[0053] The negative terminal of the diode in the left arm bridge 331 is connected to the positive terminal of the battery cell 320, and the negative terminal of the diode in the right arm bridge 332 is connected to the negative terminal of the charging power supply 310, so that a charging circuit is formed between the battery cell 320 and the charging power supply 310 to avoid reverse current.

[0054] A safety capacitor 333 and a safety resistor 334 are connected in parallel between the source and gate of each MOSFET to suppress the effects of parasitic capacitance and prevent the MOSFET from being accidentally short-circuited due to instantaneous voltage when the battery cell 320 is connected to the circuit where the charging power supply 310 is located. This protects the safety and lifespan of the structure in the circuit (in practical applications, the lifespan can be further extended by replacing the MOSFET with one that has higher reliability).

[0055] The active balancing control device provided in this application embodiment uses a control chip connected to an optocoupler. The control chip sends control signals to a MOSFET via the optocoupler to control the MOSFET's conduction state, thereby controlling whether the battery cell is connected to the charging power supply. Once the battery cell is connected, the control chip monitors voltage changes across the battery cell to determine its charging status, thus achieving active balancing control during the charging process. Simultaneously, by connecting a capacitor and resistor in parallel with the MOSFET, the impact of instantaneous voltage on the MOSFET is reduced when the battery cell is connected to the power supply, ensuring the safety of the MOSFET structure and consequently the safety of the entire circuit and the lifespan of the device.

[0056] Based on the embodiment shown in Figure 2, the specific structure of the active balancing control device 200 will be described in detail below with reference to Figure 3. The active balancing control device 200 also includes:

[0057] The optocoupler 220 includes an input terminal 221 and an output terminal 222. The input terminal 221 is a light-emitting diode 225 located at the control terminal 210, and the output terminal 222 is a photoresistor 226 located at the execution terminal 300.

[0058] Specifically, the structure of optocoupler 220 includes a light-emitting diode 225 as the input terminal 221 (refer to Figure 2, the input terminal 221, i.e., the part of optocoupler 220 belonging to the control terminal 210, and the output terminal 222, i.e. the part of optocoupler 220 belonging to the execution terminal 300) and a photoresistor 226 as the output terminal 222. When the light-emitting diode 225 is not energized, the photoresistor 226 is not illuminated, its resistance is extremely high, and the circuit containing the photoresistor 226 is in a state similar to an open circuit.

[0059] When the control chip 211 powers on the light-emitting diode 225, the light-emitting diode 225 works, and the light it produces shines on the photoresistor 226, causing the resistance of the photoresistor 226 to drop rapidly, thus making the circuit containing the photoresistor 226 conductive.

[0060] Based on this principle, the control chip 211 can control the working state of the photoresistor 226 without being directly connected to the actuator where the photoresistor 226 is located, thereby achieving electrical isolation.

[0061] In one embodiment of this disclosure, the negative terminal of the light-emitting diode 225 is connected to the chip interface 212 of the control chip 211, the positive terminal of the light-emitting diode 225 is connected to the positive and negative terminals of two adjacent cells 320 respectively, one end of the photoresistor 226 is connected to the constant current power supply 223, and the other end of the photoresistor 226 is connected to the base of the MOS transistor in the left arm bridge 331 and the right arm bridge 332 respectively.

[0062] Specifically, when the electrical signal at input terminal 221 indicates that the photoresistor 226 at output terminal 222 is turned on, the constant current power supply 223 supplies power to the base of the MOSFETs in the left and right arm bridges, causing the MOSFETs to switch to the on state. At this time, the battery cell 320 corresponding to the optocoupler 220 can be connected to the corresponding circuit of the charging power supply 310, thereby realizing the charging of the battery cell 320. At this time, the current will also flow through the light-emitting diode 225 connected to the positive and negative terminals of the battery cell 320, thereby continuously supplying power to the light-emitting diode 225, so that the charging process can continue.

[0063] In some embodiments, a control switch 213 is provided between the two chip interfaces 212 corresponding to the same battery cell 320 in the control chip 211. The control switch 213 is in the open state when the battery cell 320 is charging. When it is necessary to stop charging, the control switch 213 can be closed directly to divert the current flowing through the light-emitting diode 225, thereby reducing the brightness of the light-emitting diode 225. At this time, the resistance of the photoresistor 226 increases, which reduces the current flowing from the constant current power supply 223 to the base of the MOSFET. The MOSFET switches to the open state, thereby achieving the effect of stopping the charging of the battery cell 320.

[0064] Therefore, by controlling the working state of the light-emitting diode 225 through the control chip 211, the photoresistor 226 is controlled, and the conduction state of the MOSFET is controlled, thereby realizing the control function in active equalization control.

[0065] In one embodiment of this disclosure, the bases of the MOS transistors in the left arm bridge 331 and the right arm bridge 332 are connected to the output terminal 222 of the optocoupler 220 via diodes. The base of the MOS transistor in the left arm bridge 331 is connected to the negative terminal of the corresponding diode, and the base of the MOS transistor in the right arm bridge 332 is connected to the negative terminal of the corresponding diode.

[0066] Specifically, when the output terminal 222 of the optocoupler 220 is not turned on, in order to avoid mutual interference between the MOSFETs of the left and right arm bridges, a diode can be placed between the base of the MOSFET of the left and right arm bridges and the output terminal 222 to prevent the reverse current from interfering with the MOSFET, and to ensure the accuracy and stability of the control of the MOSFET's working state based on the control chip 211.

[0067] In one embodiment of this disclosure, a resistor is provided between the base of the MOS transistor and the negative terminal of the corresponding diode.

[0068] Specifically, by setting a resistor in conjunction with the optocoupler 220 and the diode, the current flowing through the base of the MOSFET is limited, preventing damage to the MOSFET due to overcurrent and improving the reliability and lifespan of the system.

[0069] The aforementioned improvements to the structure of the execution terminal 210 effectively enhance the service life and reliability of the MOS transistor control circuit 330, thereby improving the overall reliability of the active equalization control device 200.

[0070] In one embodiment of this disclosure, the control chip 211 is connected to the two poles of each battery cell 320 via a diode and a resistor through a chip interface 212; the positive pole of the battery cell 320 is connected to the positive pole of the adjacent diode 224, and the chip interface 212 is connected in series with the negative pole of the adjacent diode 224 through a resistor.

[0071] Specifically, the control chip 211 needs to monitor the voltage change of the battery cell 320 to determine the charging state of the battery cell 320 and feed back the charging state to the control chip 211 so that the control chip 211 can control the conduction state of the battery cell 320 with the charging power supply 310 according to the charging state of different battery cells 320, thereby achieving the effect of active equalization control.

[0072] Therefore, the control chip 211 is equipped with multiple chip interfaces 212 to monitor the voltage changes of each different battery cell 320. Each chip interface 212 is connected to the positive or negative terminal of a battery cell 320 (two chip interfaces 212 can be connected to the positive and negative terminals of the same battery cell 320 respectively), thereby realizing voltage monitoring of the battery cell 320.

[0073] Since the cells 320 are connected in series, the same chip interface 214 can be connected to the negative terminal of one cell 320 and the positive terminal of another adjacent cell 320 at the same time. Therefore, only N+1 chip interfaces 214 are needed to obtain the voltage changes of N cells 320, thereby reducing the number of components required for the overall device and saving costs.

[0074] Furthermore, by connecting a diode and a resistor in series between the battery cell 320 and the chip interface 212, the unidirectional conductivity of the diode is used to prevent the reverse current from affecting the chip interface 212 (for example, if the diode is not provided, a reverse current may be generated on the chip interface 212 when the control switch 213 is closed). The resistor is used to limit the current and divide the voltage, thus protecting the chip interface 212 from the effects of overcurrent and overvoltage.

[0075] This structural design improves the accuracy of the control chip 211 in monitoring voltage changes in the battery cell 320 and reduces abnormal detection caused by electrical interference.

[0076] The adjacent diode 221 is the diode connected to the chip interface 212 in the control terminal 210 through a resistor. To distinguish it from the diode in the execution terminal 300 and the light-emitting diode 225 in the optocoupler 220, it is referred to as the adjacent diode 221.

[0077] These diodes are all connected with their positive terminals to the battery cell 320 (one of the positive and negative terminals), and their negative terminals are connected to the chip interface 212 through a resistor. This prevents the instantaneous voltage across the battery cell 320 from accidentally turning on other components in the circuit (including the MOS transistors of the execution terminal 300 connected to other battery cells 320) when the battery cell 320 is connected to the charging power circuit. This ensures the stability and anti-interference capability of the chip interface 212 in acquiring the voltage across the battery cell 320.

[0078] In one embodiment of this disclosure, a transistor is connected in parallel between the positive and negative terminals of the battery cell 320. The base of the transistor is connected to the chip interface 212 of the control chip 211 through a resistor. The collector of the transistor is connected to the negative terminal of the light-emitting diode 225 of the optocoupler 220. The positive terminal of the light-emitting diode 225 is connected to the positive terminal of the battery cell 320 through a resistor. The emitter of the transistor is connected to the negative terminal of the battery cell 320.

[0079] Specifically, in this solution, the light-emitting diode 225 of the optocoupler 220 is not directly placed on the circuit where the positive and negative terminals of the battery cell 320 are connected to the chip interface 212, so as to avoid the instantaneous voltage of the battery cell 320 being connected to the circuit where the charging power supply 310 is located from impacting the light-emitting diode 225.

[0080] Alternatively, the LED 225 and the control chip 210 are connected in parallel (and also in parallel with the corresponding battery cell 320). In this case, the current flowing through the LED 225 is relatively small. To ensure the driving performance of the LED 225, a transistor can be placed between the negative terminal of the LED 225 and the chip interface 212 of the adjacent control chip 211. The negative terminal of the LED 225 is connected to the collector of the transistor, and the base of the transistor is connected to the chip interface 212. This enhances the electrical signal corresponding to the LED 225 at the collector through the base, thereby enhancing the driving capability of the LED 225, ensuring the driving capability of the optocoupler 220 for the MOS transistor control circuit, and improving the stability and accuracy of the control capability of the active equalization control device 200.

[0081] In practical applications, the ability to prevent false power-on can be further enhanced by adjusting the RC parameters of the transistor control terminal, thereby improving system safety.

[0082] In one embodiment of this disclosure, the positive terminal of the battery cell 320 is grounded via a capacitor.

[0083] Specifically, by connecting a capacitor in series with the positive terminal of the battery cell 320 and then grounding it, a stable voltage reference point can be provided for the control chip 211 to monitor the voltage change of the battery cell 320, thereby ensuring the accuracy of monitoring the voltage change of the battery cell 320 and thus ensuring the control accuracy of the active equalization control during the charging process of the battery cell 320.

[0084] By grounding the positive terminal of the battery cell 320, it can absorb voltage spikes of instantaneous voltage when the battery cell 320 is connected to the charging power supply 310 circuit, thus further protecting the optocoupler 220.

[0085] In one embodiment of this disclosure, a capacitor is connected in parallel between the base and emitter of the transistor, the base of the transistor is connected to the negative terminal of the adjacent diode 224, and the emitter of the transistor is connected to the positive terminal of the adjacent diode 224.

[0086] Specifically, since adjacent cells 320 (the positive terminal of one cell 320 and the negative terminal of another adjacent cell 320) are connected to the same chip interface 212 through the same adjacent diode and the same resistor, the emitter and base of the same transistor may have voltages in opposite directions. In order to avoid the reverse withstand voltage from affecting the transistor and other components on the circuit, a capacitor can be connected in parallel between the base and emitter of the transistor, and combined with the adjacent diode 224, to minimize the impact of reverse current and instantaneous voltage on the components and improve the service life of the active equalization control device 200.

[0087] In one embodiment of this disclosure, a capacitor is connected between the positive and negative terminals of the battery cell 320 and the corresponding chip interface 212. The two ends of the capacitor are connected to the negative terminal of the adjacent diode 224 through a resistor.

[0088] Specifically, by connecting a capacitor in parallel between the chip interfaces 212, the electrical signal received by the control chip 211 can be filtered to smooth signal fluctuations, better ensure the control chip 211's monitoring of the charging status of the battery cell 320, and thus ensure the control accuracy of the active balancing control device 200.

[0089] The active balancing control device provided in this disclosure further optimizes its performance by introducing various components, such as diodes, resistors, capacitors, and transistors, from both the execution and control ends. By placing diodes in the signal transmission path, unidirectionality is ensured, preventing reverse current interference to the optocoupler and control chip. Resistors limit instantaneous current, protecting the MOSFET and control chip from overcurrent damage. Capacitors filter and absorb voltage spikes, providing circuit stability and anti-interference capabilities. Transistors enhance signal driving capability, ensuring effective signal transmission. This combination of structures not only improves system safety and reliability but also enhances signal transmission accuracy and stability, solving the problems of false connection and short circuit caused by parasitic capacitance and voltage fluctuations in the prior art, and improving the effectiveness of active balancing control in the battery management system.

[0090] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0091] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0092] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An active balancing control device, characterized in that, include: The system comprises a control terminal and an execution terminal. The control terminal includes a control chip connected to the execution terminal via an optocoupler. The execution terminal includes a charging power supply, battery cells, and a MOSFET control circuit. There are at least three battery cells connected in series with adjacent cells. The control chip is connected to the two terminals of each battery cell via a chip interface. The MOSFET control circuit includes a left-hand bridge connected to the positive terminal of each battery cell and a right-hand bridge connected to the negative terminal of each battery cell. The left-hand bridge and the right-hand bridge each include a MOSFET and a diode connected in series. The source of the transistor is connected to the anode of the diode, the base of the MOSFET is connected to the optocoupler, the drain of the MOSFET in the left arm bridge is connected to the anode of the charging power supply, and the drain of the MOSFET in the right arm bridge is connected to the cathode of the battery cell; the cathode of the diode in the left arm bridge is connected to the anode of the battery cell, and the cathode of the diode in the right arm bridge is connected to the cathode of the charging power supply; a safety capacitor and a safety resistor are connected in parallel between the source and gate of the MOSFET, and the safety capacitor and the safety resistor are connected in parallel with each other.

2. The active balancing control device according to claim 1, characterized in that, The optocoupler includes an input terminal and an output terminal. The input terminal is a light-emitting diode located at the control terminal, and the output terminal is a photoresistor located at the execution terminal.

3. The active balancing control device according to claim 2, characterized in that, The negative terminal of the light-emitting diode is connected to the chip interface of the control chip, and the positive terminal of the light-emitting diode is connected to the positive and negative terminals of two adjacent cells respectively. One end of the photoresistor is connected to the constant current power supply, and the other end of the photoresistor is connected to the base of the MOS transistor in the left arm bridge and the right arm bridge respectively.

4. The active balancing control device according to claim 3, characterized in that, The bases of the MOS transistors in the left and right arm bridges are connected to the photoresistor via diodes. The base of the MOS transistor in the left arm bridge is connected to the negative terminal of the corresponding diode, and the base of the MOS transistor in the right arm bridge is connected to the negative terminal of the corresponding diode.

5. The active balancing control device according to claim 4, characterized in that, A resistor is provided between the base of the MOS transistor and the negative terminal of the corresponding diode.

6. The active balancing control device according to any one of claims 1 to 5, characterized in that, The control chip is connected to the two poles of each battery cell via a diode and a resistor through a chip interface; the positive pole of the battery cell is connected to the positive pole of the adjacent diode, and the chip interface is connected in series with the negative pole of the adjacent diode through a resistor.

7. The active balancing control device according to claim 6, characterized in that, A transistor is connected in parallel between the positive and negative terminals of the battery cell. The base of the transistor is connected to the chip interface through a resistor. The collector of the transistor is connected to the negative terminal of the light-emitting diode of the optocoupler. The positive terminal of the light-emitting diode is connected to the positive terminal of the battery cell through a resistor. The emitter of the transistor is connected to the negative terminal of the battery cell.

8. The active balancing control device according to claim 7, characterized in that, The positive terminal of the battery cell is grounded through a capacitor.

9. The active balancing control device according to claim 7, characterized in that, A capacitor is connected in parallel between the base and emitter of the transistor. The base of the transistor is connected to the negative terminal of the adjacent diode, and the emitter of the transistor is connected to the positive terminal of the adjacent diode.

10. The active equalization control device according to claim 6, characterized in that, A capacitor is connected between the positive and negative terminals of the battery cell and the corresponding chip interface. The two ends of the capacitor are connected to the negative terminal of the adjacent diode through a resistor.

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