Active equalization control system

Abstract

The embodiment of the invention provides an active equalization control system, and relates to the technical field of batteries. The system comprises a control end and an execution end, wherein the control end comprises a controller and an optocoupler; the execution end comprises a charging power supply, a battery cell, a bus, a switching element and a polarity switching circuit; the switching element is a solid-state relay or an MOS (Metal Oxide Semiconductor) tube; the bus comprises a first bus and a second bus, and the polarity switching circuit comprises a first switching element group and a second switching element group; the positive electrode of the charging power supply is connected with the first bus through the first switching element group, and the negative electrode of the charging power supply is connected with the second bus through the first switching element group; the positive electrode of the charging power supply is connected with the second bus through the second switching element group, the negative electrode of the charging power supply is connected with the first bus through the second switching element group, and the polarity switching circuit is used for switching the polarity of the charging power supply connected with the bus. According to the method, the problems of relatively high cost and insufficient control precision of an active equalization control system in related technologies are effectively solved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to an active balancing control system. Background Art

[0002] In the field of new energy vehicle technology, a battery management system (BMS) is used to control the charging process of the battery cells in the vehicle to ensure efficiency and safety. To monitor and adapt the charging progress and charging status of each cell during the charging process, control components such as the Analog Front End (AFE) and MOSFETs are combined to actively balance the charging process.

[0003] During the active balancing control process, when the battery cell is connected to the charging circuit, it is easy for the instantaneous voltage to impact the components. Therefore, in the related technology, multiple MOS tubes are redundantly set in the circuit, or components such as resistors and diodes are added to improve the safety of the circuit. This will cause the overall cost of the active balancing control system to increase, and due to the complexity of the system components, the control and monitoring accuracy of the battery cell is reduced. Summary of the Invention

[0004] The present application provides an active balancing control system to solve the problems of high cost and insufficient control accuracy of active balancing control systems in related technologies.

[0005] In a first aspect, the present application provides an active balancing control system, comprising:

[0006] Control side and execution side,

[0007] The control end includes a controller and an optocoupler;

[0008] The execution end includes a charging power supply, a battery cell, a bus, a switching element, and a polarity switching circuit. The switching element is a solid-state relay or a MOS tube.

[0009] The bus includes a first bus and a second bus, and the polarity switching circuit includes a first switching element group and a second switching element group;

[0010] The positive electrode of the charging power supply is connected to the first bus through the first switching element group, and the negative electrode of the charging power supply is connected to the second bus through the first switching element group; the positive electrode of the charging power supply is connected to the second bus through the second switching element group, and the negative electrode of the charging power supply is connected to the first bus through the second switching element group. The polarity switching circuit is used to switch the polarity of the charging power supply connected to the bus;

[0011] There are at least three battery cells, and adjacent battery cells are connected in series. Both ends of each battery cell are connected to a bus through a switching element. The output ends of two adjacent switching elements are connected to different busses respectively. Adjacent electrodes of adjacent battery cells are connected to the output end of the same switching element.

[0012] The interface of the controller is connected to the input end of the switching element through an optocoupler, and the two ends of the battery cell are connected to the interface of the controller. The controller is used to monitor the voltage, current and temperature at both ends of the battery cell, and based on the voltage, current and temperature, controls the conduction state of the switching element to control the charging process of the battery cell.

[0013] In one embodiment of the present disclosure, a first switching element group includes a first switching element and a second switching element, wherein an output end of the first switching element is respectively connected to a first bus and a positive electrode of a charging power supply, and an output end of the second switching element is respectively connected to a second bus and a negative electrode of the charging power supply; a second switching element group includes a third switching element and a fourth switching element, wherein an output end of the third switching element is respectively connected to the second bus and a positive electrode of the charging power supply, and an output end of the fourth switching element is respectively connected to the first bus and a negative electrode of the charging power supply; and input ends of the first switching element, the second switching element, the third switching element, and the fourth switching element are respectively connected to a controller, which is configured to control the conduction states of the first switching element group and the second switching element group.

[0014] In one embodiment of the present disclosure, one end of the input end of the first switching element is connected to the power supply, and the other end is connected to the input end of the second switching element, and the other end of the input end of the second switching element is connected to the controller; the output end of the controller is connected to the input end of the switching element in the polarity switching circuit through a diode, the output end of the controller is connected to the positive pole of the diode, and the input end of the switching element in the polarity switching circuit is connected to the negative pole of the diode, and the controller is used to control the working state of the switching element in the polarity switching circuit.

[0015] In one embodiment of the present disclosure, one end of the input terminal of the switching element connected to the battery cell is grounded, and the other end is connected to the interface of the controller through an OR gate and an optical coupler.

[0016] In one embodiment of the present disclosure, the output end of the OR gate is connected to the input end of the switching element, including a first type of OR gate and a second type of OR gate. The switching element corresponding to the first type of OR gate is connected to the positive pole of a battery cell and is not connected to the negative pole of other battery cells. The switching element corresponding to the second type of OR gate is respectively connected to the positive pole and negative pole of two adjacent battery cells; the input end of the first type of OR gate is respectively connected to the ground point and the output end of the optocoupler, and the input end of the second type of OR gate is respectively connected to the output ends of two adjacent optocouplers; one input end of adjacent OR gates is respectively connected to the output end of the same optocoupler; the input end of the optocoupler is respectively connected to two different interfaces of the controller, and each interface of the controller is respectively connected to an electrode of the battery cell.

[0017] In one embodiment of the present disclosure, a transistor is arranged between the interface of the controller corresponding to the positive pole of the same battery cell and the controller interface corresponding to the negative pole of the battery cell, the collector of the transistor is connected to the optocoupler input end, the other end of the optocoupler input end is connected to the controller interface corresponding to the positive pole of the battery cell, the base of the transistor is connected to the controller interface, the emitter of the transistor is connected to the controller interface corresponding to the negative pole of the battery cell, and the controller interface connected to the base of the transistor is adjacent to the controller interface corresponding to the positive and negative poles of the battery cell respectively.

[0018] In one embodiment of the present disclosure, a resistor, a capacitor and a diode are connected in parallel between the base and the emitter of the transistor, the anode of the diode is connected to the emitter of the transistor, and the cathode of the diode is connected to the base of the transistor.

[0019] In one embodiment of the present disclosure, the controller includes an analog front-end chip and a control chip. The analog front-end chip is connected to the battery cell and the switching element, and the control chip is connected to the analog front-end chip. The analog front-end chip is used to monitor the voltage, current and temperature at both ends of the battery cell and transmit them to the control chip. The control chip is used to transmit control instructions to the analog front-end chip based on the voltage, current and temperature. The control instructions are used to instruct the analog front-end chip to control the conduction state of the switching element; the control chip and the analog front-end chip are interconnected through a daisy chain circuit.

[0020] In one embodiment of the present disclosure, the control chip includes a battery management unit, or the control chip includes a micro control unit and a battery management unit connected to each other, the micro control unit and the battery management unit are connected through a universal serial bus, and the micro control unit and the universal serial bus are respectively connected to corresponding power supplies.

[0021] In one embodiment of the present disclosure, the analog front-end chip is connected to the battery cell and the switching element through a multiplexer switch.

[0022] The active balancing control system provided by the embodiment of the present disclosure, by setting up a polarity switching circuit and a bus, enables the switching element connected to the battery cell to be connected to both the positive pole and the negative pole of the charging power supply, thereby enabling the same switching element to simultaneously meet the control requirements of two adjacent switching elements. Therefore, on the basis of controlling the state of whether the battery cell is connected to the charging circuit through the switching element, the demand for the number of switching elements is reduced. Therefore, on the basis of avoiding the addition of additional structures, the controller monitors the relevant indicators of the battery cell and controls the state of the switching element, thereby realizing precise active balancing control of the charging state of multiple battery cells. At the same time, by isolating the controller and the execution end through the optical coupler, the impact of instantaneous voltage on the control end can be avoided, which not only improves the control accuracy but also reduces the structural cost, thereby ensuring the reliability and practicality of the active balancing control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0024] Figure 1 A diagram of an application scenario of the active balancing control system provided by an embodiment of the present disclosure;

[0025] Figure 2 A schematic structural diagram of an active balancing control system provided by one embodiment of the present disclosure;

[0026] Figure 3 A schematic diagram of the control end structure of an active balancing control system provided in yet another embodiment of the present disclosure;

[0027] Figure 4 A schematic diagram of the coordination relationship between various control elements provided in yet another embodiment of the present disclosure.

[0028] Among them, 100, battery management module, 111, control module, 120, connected optical coupler;

[0029] 200. Active balancing control system;

[0030] 210. Control terminal, 211. Controller, 212. Interface, 213. Power supply, 214. Analog front-end chip, 215. Control chip, 216. Battery management unit, 217. Microcontroller unit, 218. Universal serial bus, 219. Multiplexer switch, 220. Optocoupler, 230. OR gate, 231. First type OR gate, 232. Second type OR gate;

[0031] 300, execution end, 310, charging power supply, 320, battery cell, 321, switching element, 330, bus, 331, first bus, 332, second bus, 340, polarity switching circuit, 341, first switching element group, 342, second switching element group, 343, first switching element, 344, second switching element, 345, third switching element, 346, fourth switching element.

[0032] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0033] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0034] In the field of new energy vehicle technology, a battery management system (BMS) is used to control the charging process of the battery cells in the vehicle to ensure efficiency and safety. To monitor and adapt the charging progress and charging status of each cell during the charging process, control components such as the Analog Front End (AFE) and MOSFETs are combined to control the charging process of the battery cells, a process known as active balancing control.

[0035] During the active balancing control process, when the battery cell is connected to the charging circuit, it is easy for the instantaneous voltage to impact the components. Therefore, in order to ensure the safety of the system, in the relevant technology, multiple MOS tubes are redundantly set in the circuit, or components such as resistors and diodes are added to improve the safety of the circuit. This will cause the overall cost of the active balancing control system to increase, and due to the complexity of the composition of the system components, the control and monitoring accuracy of the battery cell is reduced.

[0036] The active balancing control system provided in the present application, by setting a control end and an execution end, enables the control end to control the state of the switching element of the execution end through the controller, thereby controlling whether each battery cell is connected to the charging circuit. By coordinating the bus with the polarity switching circuit, it is possible to use fewer switching elements to control whether a large number of battery cells are connected to the charging circuit. The control accuracy is guaranteed by the coordination of the controller and the switching element, thereby improving the reliability and practicality of the system.

[0037] Figure 1 The following is a schematic diagram of the application scenario of the active balancing control system provided in this application, such as Figure 1 As shown, in the active balancing control system 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 is charged and when it stops charging. When there are multiple battery cells to be charged, the active balancing control process is achieved by controlling the charging state of each battery cell.

[0038] It should be noted that Figure 1The scenario shown includes a battery management module, a control module, an interconnected optocoupler, and battery cells to be charged, and only one or a specific number of them are used as examples for illustration, but the present disclosure is not limited to this. That is, the number of battery management modules, control modules, interconnected optocouplers, and battery cells to be charged can be arbitrary.

[0039] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0040] Figure 2 The schematic diagram of the active balancing control system provided in this application is as follows: Figure 2 As shown, it includes:

[0041] The control terminal 210 and the execution terminal 300,

[0042] The control end 210 includes a controller 211 and an optical coupler 220;

[0043] The execution end 300 includes a charging power supply 310, a battery cell 320, a bus 330, a switching element 321 and a polarity switching circuit 340. The switching element is a solid-state relay or a MOS tube.

[0044] The bus 330 includes a first bus 331 and a second bus 332 , and the polarity switching circuit 340 includes a first switching element group 341 and a second switching element group 342 ;

[0045] The positive electrode of the charging power source 310 is connected to the first bus 331 via the first switching element group 341, and the negative electrode of the charging power source 310 is connected to the second bus 332 via the first switching element group 341. The positive electrode of the charging power source 310 is connected to the second bus 332 via the second switching element group 344 342, and the negative electrode of the charging power source 310 is connected to the first bus 331 via the second switching element group 344 342. The polarity switching circuit 340 is used to switch the polarity of the charging power source 310 connected to the bus 330.

[0046] There are at least three battery cells 320, and adjacent battery cells 320 are connected in series. The two ends of each battery cell 320 are connected to the bus 330 through a switching element 321. The output ends of two adjacent switching elements 321 are respectively connected to different bus lines 330, and adjacent electrodes of adjacent battery cells 320 are connected to the output ends of the same switching element 321.

[0047] The interface 212 of the controller 211 is connected to the input end of the switching element 321 through the optocoupler 220, and the two ends of the battery cell 320 are connected to the interface 212 of the controller 211. The controller 211 is used to monitor the voltage, current and temperature at both ends of the battery cell 320, and based on the voltage, current and temperature, control the conduction state of the switching element to control the charging process of the battery cell 320.

[0048] Specifically, Figure 2 It is mainly for the display of the execution end. Figure 3 It is a structural diagram of the control end, therefore, Figure 2 The middle execution end is to show the specific connection relationship between the controller 211 and the battery cell 320 and the switching element 321, for example, Figure 2 and Figure 3 , RAT1 in Figure 2 One end is connected to the positive terminal of U1, and the other end is connected to the positive terminal of U1. Figure 3 In the embodiment, the interface 212 of the controller 211 indicated by the reference numeral S1 is connected; for example, CTR1 is connected to the interface 212 of the controller 211 indicated by the reference numeral S1; Figure 2 The middle point is the input end of the switching element 321. Figure 3 The middle is connected to the output terminal of the first type OR gate 231. Figure 3 The specific connection relationship includes components such as resistors, diodes, transistors, optocouplers, capacitors, and controllers.

[0049] The above examples illustrate the connection relationships of related structures. The accompanying drawings and examples only show some of the structures. In actual applications, the number of structures is not limited by the numbers in the accompanying drawings. For example, only cells U1 to U5 are shown, but there can actually be more, such as U10 and U16. The same is true for related connection points. For example, the number of RATs can be extended to match the number of cells. The relevant principles can be understood and replicated by those skilled in the art without requiring creative effort, and will not be elaborated on here.

[0050] In this solution, the control end 210 is a part used to achieve active balancing control by outputting a control signal during the charging process of the battery cell 320. The controller 211 can be a control unit (BCU, full name Battery Control Unit) in a battery management system (BMS, full name Battery Management System), or a separately set micro control unit (MCU), or a combination of an analog front end (AFE, full name Analog Front End) 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 generates a control instruction based on the processing of the monitoring results (i.e., sending electrical signals of different levels to the switching element 321 through the optocoupler 220 to control the conduction state of the switching element 321, and then 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.

[0051] The function of the optocoupler 220 is to transmit control instructions between the control terminal 210 and the execution terminal 300 and to achieve electrical isolation of the signal, thereby ensuring that the control signal is not interfered with by the outside world during transmission, and at the same time avoiding the influence of excessively high voltage values at the execution terminal 300 on the controller 211, thereby improving the safety and reliability of the system.

[0052] The execution end 300 is used to control whether the battery cell 320 is connected to the corresponding circuit of the charging power source 310 according to the control instruction sent by the control end 210.

[0053] 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.

[0054] The two ends of the battery cell 320 are connected to the bus 330 through the switching element 321, and then connected to the charging power supply 310 through the bus 330. Therefore, when the switching element 321 is in the on state, a charging circuit can be formed between the battery cell 320 and the charging power supply 310 to charge the battery cell 320; the input end of the switching element 321 is connected to the controller 211, so that the controller 211 can control the on state of the switching element 321.

[0055] The controller 211 is connected to the two poles of each battery cell 320 respectively, so that the analog controller 211 monitors the voltage, current and temperature of each battery cell 320 to determine the charging state of the battery cell 320, and then controls the conduction state of the switching element 321 according to the charging state, thereby realizing active balancing control.

[0056] The switching element 321 can be a solid-state relay or a MOS tube, both of which can realize the control function. For the convenience of demonstration, in this solution, only the switching element 321 is shown as a solid-state relay. However, to actually replace it with a solid-state relay, it is only necessary to remove the power supply structure at the input end of the switching element 321. Other parts do not need to be adjusted. The relevant changes are work that can be completed by technical personnel in this field without creative labor, so they will not be repeated here.

[0057] The polarity switching circuit 340 is configured to select one of the first switching element group 341 and the second switching element group 342 to be in an active state (and the other to be in an inactive state) based on control by the controller 211. For example, when the first switching element group 341 is in an active state, the first bus 331 is connected to the positive electrode of the charging power source 310, and the second bus 332 is connected to the negative electrode of the charging power source 310. The switching element 321 connected to the first bus 331 is connected to the positive electrode of the charging power source 310, and the switching element 321 connected to the second bus 332 is connected to the negative electrode of the charging power source 310. When the second switching element 342 is in an active state, the polarity of the charging power source 310 connected to the switching element 321 is reversed. Thus, the polarity of the charging power source 310 connected to each switching element 321 can be controlled by the polarity switching circuit 340.

[0058] For the switching element 321 shared by two adjacent battery cells 320, when it is necessary to charge the battery cell whose negative pole is connected to the switching element 321, the bus 330 connected to the switching element 321 can be switched to be connected to the negative pole of the charging power source 310 through the polarity switching circuit 340; when it is necessary to charge the battery cell whose positive pole is connected to the switching element 321, the bus 330 connected to the switching element 321 can be switched to be connected to the negative pole of the charging power source 310 through the polarity switching circuit 340. In this way, the same switching element 321 can meet the different charging requirements of adjacent battery cells 320, thereby reducing the number of switching elements 320 without affecting the normal charging function.

[0059] There is usually only one controller 211, but there are multiple interfaces 212. For example, through each interface 212 ( Figure 2 The controller 211 also includes a separate interface 212, which is connected to the switching element 321 in the polarity switching circuit 340 to control the conduction state of the switching element 321.

[0060] The active balancing control system provided in the embodiment of the present application, by setting up a polarity switching circuit and bus coordination, enables the switching element connected to the battery cell to be connected to both the positive pole of the charging power supply and the negative pole of the charging power supply, thereby enabling the same switching element to simultaneously meet the control requirements of two adjacent switching elements, thereby reducing the demand for the number of switching elements on the basis of controlling the state of whether the battery cell is connected to the charging circuit through the switching element, thereby avoiding the addition of additional structures, monitoring the battery cell-related indicators through the controller, and controlling the state of the switching element, thereby achieving precise active balancing control of the charging state of multiple battery cells, and at the same time, by isolating the controller and the execution end through the optical coupler, the impact of instantaneous voltage on the control end can be avoided, which not only improves the control accuracy but also reduces the structural cost, thereby ensuring the reliability and practicality of the active balancing control system.

[0061] exist Figure 2 Based on the embodiment, the following Figure 3 , the specific structure of the active balancing control system 200 is described in detail, and the active balancing control system 200 also includes:

[0062] The first switching element group 341 includes a first switching element group 341 and a second switching element 344. The output end of the first switching element group 341 is connected to the first bus 331 and the positive electrode of the charging power source 310, respectively. The output end of the second switching element 344 is connected to the second bus 332 and the negative electrode of the charging power source 310, respectively. The second switching element group 344 includes a third switching element 345 and a fourth switching element 346. The output end of the third switching element 345 is connected to the second bus 332 and the positive electrode of the charging power source 310, respectively. The output end of the fourth switching element 346 is connected to the first bus 331 and the negative electrode of the charging power source 310, respectively. The input ends of the first switching element group 341, the second switching element 344, the third switching element 345, and the fourth switching element 346 are respectively connected to the controller 211. The controller 211 is used to control the conduction state of the first switching element group 341 and the second switching element group 342.

[0063] Specifically, two switching elements 321 form a switching element group to realize the function of connecting the charging power source 310 and different buses 330 respectively. The controller 211 controls the conduction state of each switching element 321 in the polarity switching circuit 340 to realize the switching of the polarity of the bus 330 corresponding to the charging power source 310.

[0064] In one embodiment of the present disclosure, one end of the input end of the first switching element 343 is connected to the power supply 213, and the other end is connected to the input end of the second switching element 344, and the other end of the input end of the second switching element 344 is connected to the controller 211; the output end of the controller 211 is connected to the input end of the switching element in the polarity switching circuit 340 through a diode, the output end of the controller 211 is connected to the positive pole of the diode, and the input end of the switching element in the polarity switching circuit 340 is connected to the negative pole of the diode, and the controller 211 is used to control the working state of the switching element in the polarity switching circuit 340.

[0065] Specifically, the power supply 213 is used to supply power to each switching element 321 to ensure normal operation of the switching element 321 , and a diode is provided to prevent the current of the power supply 213 from flowing back to the controller 211 .

[0066] The input end of the switching element 321 can be a light-emitting diode. When the controller 211 sends an electrical signal with the same voltage as the power supply 213 (such as 5V) to the switching element 321 in the polarity switching circuit 340, at this time, the voltages at both ends of the input end of each switching element 321 are equal, and no current can be formed, so that the light-emitting diode of the switching element 321 does not work, and the output end of the switching element 321 is in a non-conducting state; and when the controller 211 does not output an electrical signal to the switching element 321, the switching element 321 is in a conducting state. At this time, by setting a diode, the current of the power supply 213 can be prevented from flowing back.

[0067] In one embodiment of the present disclosure, one input end of the switching element 321 connected to the battery cell 320 is grounded, and the other end is connected to the interface 212 of the controller 211 through the OR gate 230 and the optocoupler 220 .

[0068] Specifically, since the number of battery cells 320 is less than the number of switching elements 321, and the number of optocouplers 220 corresponds to the number of battery cells 320, the OR gate 230 is set so that the OR gate 230 corresponds to the number of switching elements 321. The interface 212 of the controller 211 is transmitted to the corresponding switching element 321 through the optocoupler 220 through the OR gate 230, thereby realizing the state control of each switching element 321.

[0069] In one embodiment of the present disclosure, the output end of the OR gate 230 is connected to the input end of the switching element, including a first type OR gate 231 and a second type OR gate 232. The switching element corresponding to the first type OR gate 231 is connected to the positive pole of a battery cell 320 and is not connected to the negative pole of other battery cells 320. The switching element corresponding to the second type OR gate 232 is respectively connected to the positive pole and negative pole of two adjacent battery cells 320; the input end of the first type OR gate 231 is respectively connected to the ground point and the output end of the optocoupler 220, and the input end of the second type OR gate 232 is respectively connected to the output ends of two adjacent optocouplers 220; one input end of adjacent OR gates 230 is respectively connected to the output end of the same optocoupler 220; the input end of the optocoupler 220 is respectively connected to two different interfaces 212 of the controller 211, and each interface 212 of the controller 211 is respectively connected to an electrode of the battery cell 320.

[0070] Specifically, the output end of the optocoupler 220 that is not connected to the OR gate 230 is connected to the power supply 213 .

[0071] For the first type OR gate 231 , when the signal at the output of the optocoupler 220 reaches the input of the first type OR gate 231 , the first type OR gate 231 directly outputs the electrical signal from the output because the other input is grounded.

[0072] For the second type of OR gate 232 , when the optocoupler 220 connected to any input terminal thereof sends a signal, the OR gate 230 can output an electrical signal, thereby switching the corresponding switching element 321 of the OR gate 230 to the on state.

[0073] By connecting one input end of adjacent OR gates 230 to the output end of the same optocoupler 220 , one optocoupler 220 can simultaneously control two adjacent OR gates 230 , thereby achieving control of the switching elements 321 on both sides of the battery cell 320 corresponding to one optocoupler 220 .

[0074] The two interfaces 212 of the controller 211 are connected to the input end of the optocoupler 220 so that the optocoupler 220 can receive signals and ensure the normal operation of the optocoupler 220. The interface 212 of each controller 211 is connected to an electrode of the battery cell 320 respectively so that the controller 211 can receive the signal transmitted by the battery cell 320 and realize the monitoring of the status of the battery cell 320.

[0075] At the same time, the connection point between the battery cell 320 and the controller 211 also corresponds to the input end of the optocoupler 220. Since the optocoupler 220 corresponds to the battery cell 320, when the battery cell 320 is in a charging state, the current at both ends will flow into the input end of the optocoupler 220, so that the optocoupler 220 corresponding to the battery cell 320 is in a continuous working state, thereby ensuring that the optocoupler 220 continues to output a control signal to the switching element 321 through the corresponding two OR gates 230, so that the switching element 321 is continuously in a conductive state, thereby ensuring the continuation of the charging process.

[0076] When the battery cell 320 no longer needs to be charged, a high level is output through the controller 211 interface connected to the other end (i.e., the negative terminal) of the output end of the optocoupler 220 that is connected to the light-emitting diode (the input end of the optocoupler 220 is a light-emitting diode, and the output end is a photoresistor), so that there is no forward potential difference between the two ends of the light-emitting diode in the optocoupler 220, and it no longer works, thereby cutting off the current flowing to the OR gate 230 and the switching element 321, and switching the switching element 321 to a non-conducting state.

[0077] In one embodiment of the present disclosure, a transistor is arranged between the interface 212 of the controller 211 corresponding to the positive pole of the same battery cell 320 and the interface 212 of the controller 211 corresponding to the negative pole of the battery cell 320, the collector of the transistor is connected to the input end of the optocoupler 220, the other end of the input end of the optocoupler 220 is connected to the interface 212 of the controller 211 corresponding to the positive pole of the battery cell 320, the base of the transistor is connected to the interface 212 of the controller 211, the emitter of the transistor is connected to the interface 212 of the controller 211 corresponding to the negative pole of the battery cell 320, and the interface 212 of the controller 211 connected to the base of the transistor is adjacent to the interface 212 of the controller 211 corresponding to the positive and negative poles of the battery cell 320 respectively.

[0078] Specifically, by setting up a transistor and connecting the base of the transistor to the interface 212 of the controller 211, the electrical signal corresponding to the light-emitting diode of the optocoupler 220 at the collector is enhanced through the base, thereby enhancing the driving ability of the light-emitting diode, ensuring the driving ability of the optocoupler 220 on the switching element 321, and improving the stability and control accuracy of the control ability of the active balancing control system 200.

[0079] In one embodiment of the present disclosure, a resistor, a capacitor and a diode are connected in parallel between the base and the emitter of the transistor, the anode of the diode is connected to the emitter of the transistor, and the cathode of the diode is connected to the base of the transistor.

[0080] Specifically, since the adjacent electrodes of adjacent battery cells 320 (the positive electrode of one battery cell 320 and the negative electrode of another adjacent battery cell 320) are connected to the same interface 212 of the controller 211, voltages in opposite directions may appear between the emitter and base of the same transistor. In order to avoid the influence of reverse voltage resistance on the transistor and other components on the circuit, a capacitor can be connected in parallel between the base and emitter of the transistor, and then combined with a diode to maximize the prevention of the influence of reverse current and transient voltage on components, thereby improving the service life of the active balancing control system 200.

[0081] In one embodiment of the present disclosure, the controller 211 includes an analog front-end chip 214 and a control chip 215. The analog front-end chip 214 is connected to the battery cell 320 and the switching element, and the control chip 215 is connected to the analog front-end chip 214. The analog front-end chip 214 is used to monitor the voltage, current and temperature at both ends of the battery cell 320 and transmit them to the control chip 215. The control chip 215 is used to transmit control instructions to the analog front-end chip 214 based on the voltage, current and temperature. The control instructions are used to instruct the analog front-end chip 214 to control the conduction state of the switching element; the control chip 215 and the analog front-end chip 214 are interconnected through a daisy chain circuit.

[0082] Specifically, refer to Figure 4 , which is a schematic diagram of the coordination relationship between various control components. Figure 4 To illustrate, the analog front-end chip 214 is responsible for signal monitoring to improve the accuracy of signal monitoring, and the control chip 215 is used to independently perform data processing and signal transmission to ensure the accuracy of data processing, thereby ensuring the accuracy and reliability of the control end 210's control of the charging process of the execution end 300; communication is carried out through a daisy chain structure to simplify wiring, and at the same time, capacitance isolation is achieved between the analog front-end chip 214 and the control chip 215. When the analog front-end chip 214 is abnormal, the safety of the control chip 215 is guaranteed, thereby improving the overall reliability of the system.

[0083] In one embodiment of the present disclosure, the control chip 215 includes a battery management unit 216, or the control chip 215 includes a microcontroller unit 217 and a battery management unit 216 connected to each other, the microcontroller unit 217 and the battery management unit 216 are connected via a universal serial bus 218, and the microcontroller unit 217 and the universal serial bus 218 are respectively connected to the corresponding power supply 213.

[0084] Specifically, as described in the aforementioned embodiments, the microcontroller unit 217 and the battery management unit 216 are combined to control the charging process according to a predetermined cell charging strategy or active balancing control strategy. These strategies are typically stored in the BCU. For example, a strategy may be to prioritize pausing the charging of a cell 320 after it is 80% full, and then charging other cells 320 with less than 20% charge until the other cells 320 are also 80% full, at which point charging of that cell 320 resumes. Alternatively, a cell 320 may be fully charged before charging the other cells 320. Alternatively, adjacent cells 320 may not be charged simultaneously to ensure safety. The battery management unit 216 then breaks down the strategy into instructions and sends them to the microcontroller unit 217. Based on the instructions, the microcontroller unit 217 sends specific level signals to the analog front-end chip 214 via a daisy chain to implement specific control of the charging process.

[0085] In one embodiment of the present disclosure, the analog front-end chip 214 is connected to the battery cell 320 and the switching element 321 through the multiplexing switch 219 .

[0086] Specifically, a multiplexing switch 219 is set to realize the connection between the analog front-end chip 214 and the battery cell 320 and the switching element 321, so as to solve the problem that the analog front-end chip 214 usually does not have so many interfaces 212, and ensure the signal transmission between the analog front-end chip 214 and the battery cell 320 and the switching element 321.

[0087] The active balancing control system provided by the embodiment of the present disclosure further optimizes the performance of the active balancing control system by introducing a variety of elements at the execution end and the control end, such as switching elements, diodes, resistors, capacitors, transistors, OR gates and optocouplers. Through the cooperation of OR gates and optocouplers, the state control of the switching elements at both ends of the battery cell is realized, and through the cooperation of the battery cell and the transistor, the signal of the battery cell can only drive the optocoupler to work, ensuring the continuation of the charging process of the active balancing control and ensuring the accuracy and stability of the control. Through the combination of these structures, not only the safety and reliability of the system are improved, but also the accuracy and stability of signal transmission are enhanced, solving the problems of high cost and insufficient control accuracy of the active balancing control system in the prior art, and improving the availability of active balancing control of the battery management system.

[0088] In the above embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in a particular embodiment, please refer to the relevant description of other embodiments. The technical features of the above embodiments can be combined in any way. To keep the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0090] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. An active balancing control system, characterized in that: The steps include: Control side and execution side, The control end includes a controller and an optical coupler; The execution end includes a charging power supply, a battery cell, a bus, a switching element and a polarity switching circuit, and the switching element is a solid-state relay or a MOS tube; The bus includes a first bus and a second bus, and the polarity switching circuit includes a first switching element group and a second switching element group; The positive electrode of the charging power source is connected to the first bus through a first switching element group, and the negative electrode of the charging power source is connected to the second bus through the first switching element group; the positive electrode of the charging power source is connected to the second bus through a second switching element group, and the negative electrode of the charging power source is connected to the first bus through the second switching element group. The polarity switching circuit is used to switch the polarity of the charging power source connected to the bus; There are at least three battery cells, adjacent battery cells are connected in series, both ends of each battery cell are connected to a bus via a switching element, the output ends of two adjacent switching elements are connected to different buses, and adjacent electrodes of adjacent battery cells are connected to the output end of the same switching element; The interface of the controller is connected to the input end of the switching element through an optocoupler, and the two ends of the battery cell are connected to the interface of the controller. The controller is used to monitor the voltage, current and temperature at both ends of the battery cell, and based on the voltage, current and temperature, controls the conduction state of the switching element to control the charging process of the battery cell.

2. The active balancing control system according to claim 1, characterized in that: The first switching element group includes a first switching element and a second switching element, wherein the output end of the first switching element is connected to the first bus and the positive electrode of the charging power supply respectively, and the output end of the second switching element is connected to the second bus and the negative electrode of the charging power supply respectively; The second switching element group includes a third switching element and a fourth switching element, wherein the output end of the third switching element is connected to the second bus and the positive electrode of the charging power supply, respectively, and the output end of the fourth switching element is connected to the first bus and the negative electrode of the charging power supply, respectively. Input ends of the first switching element, the second switching element, the third switching element, and the fourth switching element are respectively connected to a controller, and the controller is used to control the conduction states of the first switching element group and the second switching element group.

3. The active balancing control system according to claim 2, characterized in that: One end of the input end of the first switching element is connected to the power supply, and the other end is connected to the input end of the second switching element, and the other end of the input end of the second switching element is connected to the controller; The output end of the controller is connected to the input end of the switching element in the polarity switching circuit through a diode. The output end of the controller is connected to the positive pole of the diode, and the input end of the switching element in the polarity switching circuit is connected to the negative pole of the diode. The controller is used to control the working state of the switching element in the polarity switching circuit.

4. The active balancing control system according to claim 1, characterized in that: One end of the input end of the switching element connected to the battery cell is grounded, and the other end is connected to the interface of the controller through an OR gate and an optical coupler.

5. The active balancing control system according to claim 4, characterized in that: The output end of the OR gate is connected to the input end of the switching element, which includes a first type of OR gate and a second type of OR gate. The switching element corresponding to the first type of OR gate is connected to the positive electrode of a battery cell and is not connected to the negative electrode of other battery cells. The switching element corresponding to the second type of OR gate is respectively connected to the positive electrode and negative electrode of two adjacent battery cells; the input end of the first type of OR gate is respectively connected to the ground point and the output end of the optocoupler, and the input end of the second type of OR gate is respectively connected to the output ends of two adjacent optocouplers; One input terminal of adjacent OR gates is respectively connected to the output terminal of the same optocoupler; The input end of the optical coupler is connected to two different interfaces of the controller respectively, and the interface of each controller is connected to an electrode of the battery cell respectively.

6. The active balancing control system according to claim 5, characterized in that: A transistor is arranged between the interface of the controller corresponding to the positive pole of the same battery cell and the controller interface corresponding to the negative pole of the battery cell. The collector of the transistor is connected to the optocoupler input end, and the other end of the optocoupler input end is connected to the controller interface corresponding to the positive pole of the battery cell. The base of the transistor is connected to the controller interface, and the emitter of the transistor is connected to the controller interface corresponding to the negative pole of the battery cell. The controller interface connected to the base of the transistor is adjacent to the controller interface corresponding to the positive and negative poles of the battery cell respectively.

7. The active balancing control system according to claim 6, characterized in that: A resistor, a capacitor and a diode are connected in parallel between the base and the emitter of the transistor, the anode of the diode is connected to the emitter of the transistor, and the cathode of the diode is connected to the base of the transistor.

8. The active balancing control system according to any one of claims 1 to 7, characterized in that: The controller includes an analog front-end chip and a control chip, the analog front-end chip is connected to the battery cell and the switching element, the control chip is connected to the analog front-end chip, the analog front-end chip is used to monitor the voltage, current and temperature at both ends of the battery cell, and transmit them to the control chip, the control chip is used to transmit control instructions to the analog front-end chip based on the voltage, current and temperature, and the control instructions are used to instruct the analog front-end chip to control the conduction state of the switching element; The control chip and the analog front-end chip are connected to each other via a daisy chain circuit.

9. The active balancing control system according to claim 8, characterized in that: The control chip includes a battery management unit, or The control chip includes a micro control unit and a battery management unit that are connected to each other. The micro control unit and the battery management unit are connected via a universal serial bus. The micro control unit and the universal serial bus are respectively connected to corresponding power supplies.

10. The active balancing control system according to claim 8, characterized in that: The analog front-end chip is connected to the battery cell and the switching element through a multiplex switch.

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