Multi-string BMS charging reverse connection protection circuit

Abstract

The invention relates to a multi-string BMS (battery management system) charging reverse connection protection circuit, which comprises a BMS control system, a switch management module, a reverse connection detection module and a switch driving module, and is characterized in that a driving signal output end of the BMS control system is connected with a driving signal input end of the switch driving module; the signal output end of the reverse connection detection module is connected with the detection signal input end of the BMS control system and the first enable signal input end of the switch driving module, and the enable signal output end of the BMS control system is connected with the second enable signal input end of the switch driving module. And the enable signal output end of the switch driving module is connected with the enable signal input end of the switch management module so as to control the on-off of the switch management module. After the switch driving module receives signals from the reverse connection detection module and the BMS control system at the same time, on-off of the switch management module can be immediately controlled, the BMS control system makes a protection response, and therefore the safety and reliability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of a multi-string BMS charging reverse connection protection circuit, and in particular to a multi-string BMS charging reverse connection protection circuit. Background Art

[0002] At present, the reverse charging protection mechanism is generally missing in the multi-string BMS circuits used in the current industry. Since lithium battery packs are usually composed of multiple cells connected in series (such as 48V, 60V, 72V and other systems), when the positive and negative poles of the charger are reversed, if the BMS circuit does not have a perfect protection design, the battery pack will be subjected to reverse current shock, which will cause damage to the cell, internal short circuit, and even thermal runaway risk. At the same time, the charger itself also burns the rectifier bridge or power switch tube due to reverse voltage, damages the core circuit of the charger, and affects the service life. For example, in applications such as electric bicycles, electric motorcycles, and energy storage devices, users mistakenly reverse P+ and P- due to operational errors during charging. In a BMS system without reverse connection protection, the reverse current flows directly into the battery, causing it to charge at abnormal polarity, causing serious damage to the battery pack. At the same time, due to abnormal current, the MOS tube, fuse, and PCB harness inside the BMS are overheated or even burned. On the other hand, the charger has internal current reflux in the reverse connection state, burning the rectifier bridge or MOS tube, causing the entire charging system to fail. Therefore, a BMS that lacks reverse charging protection not only affects the battery life, but also poses a safety hazard. Summary of the invention

[0003] In order to solve the problem that the reverse charging protection mechanism in a multi-string BMS circuit is generally missing, resulting in reduced battery life and high safety risks, the present application provides a multi-string BMS reverse charging protection circuit.

[0004] A multi-string BMS charging reverse connection protection circuit, the multi-string BMS charging reverse connection protection circuit comprising a battery module, a BMS control system, a switch management module, a reverse connection detection module and a switch driving module, the battery module, the switch management module and the charger are connected in sequence to form a power supply circuit for powering the charger, the balanced signal output end of the battery module is connected to the balanced signal input end of the BMS control system, the drive signal output end of the BMS control system is connected to the drive signal input end of the switch driving module, the signal input end of the reverse connection detection module is connected to a common node in the power supply circuit, the signal output end of the reverse connection detection module is respectively connected to the detection signal input end of the BMS control system and the first enable signal input end of the switch driving module, the enable signal output end of the BMS control system is connected to the second enable signal input end of the switch driving module, and the enable signal output end of the switch driving module is connected to the enable signal input end of the switch management module to control the on and off of the switch management module.

[0005] By adopting the above technical solution, by introducing the reverse connection detection module, when the reverse connection detection module detects that the charger polarity is wrong, it immediately sends a signal to the detection signal input end of the BMS control system, so that the BMS control system responds to protection, and synchronously sends a first enable signal to the switch drive module. At the same time, the enable signal output end of the BMS control system also provides an additional control signal to the switch drive module to ensure that the drive module correctly performs the protection operation. After receiving these signals, the switch drive module will further send a control instruction to the switch management module to quickly cut off the power supply circuit to prevent the wrong connection of the charger from damaging the battery or BMS system. It can quickly cut off the circuit to prevent the current backflow caused by misoperation, and avoid thermal runaway, MOS tube breakdown or PCB overcurrent burning caused by reverse current entering the battery pack. In addition, the solution establishes a multi-level protection logic between the BMS control system and the switch drive module, so that the system has a dual insurance mechanism of independent hardware detection + MCU logic judgment. Even when the MCU fails or the control logic is abnormal, the hardware can still ensure that the power supply path is cut off, thereby improving the safety and reliability of the entire system. The implementation of this reverse connection protection circuit enables the multi-string BMS charging system to operate more stably in complex application scenarios (such as electric vehicles, electric motorcycles, energy storage systems, etc.), and effectively reduces the risk of equipment damage caused by user misoperation or external factors.

[0006] Preferably, the BMS control system includes a power management front-end module and a main control module, the power management front-end module includes a passive balancing unit, a front-end management chip AFE1 and a front-end management chip AFE2, the balancing signal input end of the passive balancing unit is connected to the balancing signal output end of the battery cell module, the first balancing detection output end of the passive balancing unit is connected to the balancing detection input end of the front-end management chip AFE1, the second balancing detection output end of the passive balancing unit is connected to the balancing detection input end of the front-end management chip AFE2, the data communication end of the front-end management chip AFE1 is connected to the first data communication end of the main control module, the data communication end of the front-end management chip AFE2 is connected to the second data communication end of the main control module, the drive signal output end of the front-end management chip AFE1 is connected to the drive signal input end of the switch drive module, the detection signal input end of the main control module is connected to the signal output end of the reverse connection detection module, and the enable signal output end of the main control module is connected to the second enable signal input end of the switch drive module.

[0007] By adopting the above technical solution, the functions of balanced management, data collection and intelligent control are realized through the combination of the power management front-end module and the main control module. The front-end management chip AFE1 and the front-end management chip AFE2 monitor the status of different cells respectively to ensure balanced charging and discharging of the battery pack. At the same time, the data is centrally processed through the main control module, thereby improving the system's ability to perceive abnormal situations. When abnormal situations such as reverse charging or overcurrent are detected, the BMS can make quick decisions and perform protection actions through the switch drive module to achieve more accurate charging and discharging management and improve battery life and safety.

[0008] Preferably, the switch management module includes a charging switch module and a discharging switch module which are sequentially connected to the power supply circuit, and the switch driving module includes a discharging driving management unit and a charging driving management unit. The enable signal output end of the discharging driving management unit is connected to the enable signal input end of the discharging switch module, and the enable signal output end of the charging driving management unit is connected to the enable signal input end of the charging switch module. Both the discharging driving management unit and the charging driving management unit are controlled by the enable signal of the front-end management chip AFE1, thereby controlling the on and off of the charging switch module or the discharging switch module.

[0009] By adopting the above technical solution, the switch management module and the switch drive module can be used to accurately control the on and off of the charging and discharging paths. The independent control strategy of the discharge switch module and the charging switch module can quickly switch between the charging and discharging modes, and quickly disconnect the corresponding path under abnormal conditions to ensure charging and discharging safety. At the same time, the front-end management chip AFE1 uniformly controls charging and discharging, so that the system can adjust the switch state in real time, improve the response speed, and prevent false triggering or protection failure.

[0010] Preferably, the discharge drive management unit includes a drive chip U2, a transistor Q4 and a resistor R14, the drive signal input end of the drive chip U2 is connected to the drive signal output end of the front-end management chip AFE1, the common node between the drive signal input end of the drive chip U2 and the drive signal output end of the front-end management chip AFE1 is connected to the first conduction end of the transistor Q4, the second conduction end of the transistor Q4 is grounded, the controlled end of the transistor Q4 is connected to the signal output end of the reverse connection detection module, the enable signal input end of the drive chip U2 is connected to the enable signal output end of the main control module, the output end of the drive chip U2 is connected to the first end of the resistor R14, the second end of the resistor R14 is connected to the enable signal input end of the discharge switch module, and the common node between the output end of the drive chip U2 and the first end of the resistor R14 is connected to the power input end of the charging drive management unit.

[0011] By adopting the above technical solution, a highly efficient discharge drive management unit is formed by combining the driver chip U2 with the transistor Q4, which can stably drive the discharge switch module and quickly close the discharge path when the reverse connection detection module is triggered. As a signal switch, the transistor Q4 can directly pull down the driver chip U2 drive signal when the reverse connection occurs, so that the MOS tube is quickly turned off, which greatly improves the protection response speed of the circuit and avoids battery damage or thermal runaway caused by reverse current.

[0012] Preferably, the charging drive management unit includes an acceleration shutdown subunit, a MOS tube M1, a MOS tube Q1, a resistor R2, a resistor R3, a resistor R5 and a resistor R6, the first conduction end of the MOS tube M1 is connected to a DC power supply, the second conduction end of the MOS tube M1 is connected to a first end of the acceleration shutdown subunit, the second end of the acceleration shutdown subunit is connected to an enable signal input end of the charging switch module, the first end of the resistor R2 is connected to the power output end of the discharge drive management unit, the first end of the resistor R3 is connected to the MOS A common node between the controlled end of the transistor M1 is connected to the second end of the resistor R2, the second end of the resistor R3 is connected to the first conduction end of the MOS transistor Q1, the second conduction end of the MOS transistor Q1 is grounded, the enable signal output end of the front-end management chip AFE1 is connected to the first end of the resistor R5, the second end of the resistor R5 is connected to the controlled end of the MOS transistor Q1, the common node between the second end of the resistor R5 and the controlled end of the MOS transistor Q1 is connected to the first end of the resistor R6, and the second end of the resistor R6 is grounded.

[0013] By adopting the above technical solution and the multi-level control strategy of the charging drive management unit, the charging path can be stably turned on during normal charging and quickly turned off under abnormal conditions. Through the joint control of MOS tube M1, MOS tube Q1 and current limiting resistor, the opening and closing of the charging switch module is more stable, avoiding damage to the battery caused by charging transient current impact, and also improving the durability and working stability of the charging MOS tube.

[0014] Preferably, the acceleration shutdown subunit includes a transistor Q2, a transistor Q3, a resistor R4, a resistor R7, a diode D1 and a diode D2, a positive terminal of the diode D2 is connected to the second conduction end of the MOS transistor M1, a negative terminal of the diode D2 is connected to the positive terminal of the diode D1, a negative terminal of the diode D1 is connected to the enable signal input terminal of the charging switch module, a common node between the negative terminal of the diode D1 and the enable signal input terminal of the charging switch module is connected to the first end of the resistor R4, a second end of R4 is connected to the first conduction end of the transistor Q2, the second conduction end of the transistor Q2 is connected to the controlled end of the transistor Q3, a common node between the negative terminal of the diode D2 and the positive terminal of the diode D1 is respectively connected to the first end of the resistor R7, the controlled end of the transistor Q2 and the first conduction end of the transistor Q3, a second end of the resistor R7 is grounded, and a second conduction end of the transistor Q3 is grounded.

[0015] By adopting the above technical solution, the circuit introduces an accelerated shutdown subunit in the charging drive management unit to increase the MOS tube shutdown speed and prevent the residual current in the charging circuit from affecting the charging management accuracy. When the charging MOS needs to be turned off, the accelerated shutdown circuit can quickly pull down the control signal to quickly put the MOS into the cut-off state, effectively avoiding the battery from being mischarged due to the MOS hysteresis effect, and improving the rapid response capability and safety performance of the BMS.

[0016] Preferably, the discharge switch module includes a MOS tube MD1 and a MOS tube MD2, and the charging switch module includes a MOS tube MC1 and a MOS tube MC2, the first conductive end of the MOS tube MD1 is connected to the negative end of the battery cell module, the second conductive end of the MOS tube MD1 is connected to the first conductive end of the MOS tube MC1, the second conductive end of the MOS tube MC1 is connected to the negative end of the charger, the first conductive end of the MOS tube MD2 is connected to the negative end of the battery cell module, the second conductive end of the MOS tube MD2 is connected to the first conductive end of the MOS tube MC2, and the second conductive end of the MOS tube MC2 is connected to the negative end of the charger, the enable signal output end of the discharge drive management unit is respectively connected to the controlled end of the MOS tube MD1 and the controlled end of the MOS tube MD2, and the enable signal output end of the charging drive management unit is respectively connected to the controlled end of the MOS tube MC1 and the controlled end of the MOS tube MC2.

[0017] By adopting the above technical solution, an independent MOS tube group is used, MOS tube MD1 and MOS tube MD2 are used as discharge switches, MOS tube MC1 and MOS tube MC2 are used as charging switches, and they are controlled separately by independent drive units, so that the system can manage the charging and discharging paths more accurately. Compared with the structure of sharing MOS tubes in traditional solutions, this design can effectively reduce the problem of MOS tube overheating caused by current direction switching, and can independently control each switch during charging or discharging, thereby improving the safety and durability of the system.

[0018] Preferably, the power management front-end module also includes a power management unit, and the power input end of the power management unit is connected to the positive end of the battery cell module. The power output end of the power management unit outputs power to the front-end management chip AFE2 and the main control module for power supply on the one hand, and converts it into DC power and outputs it to the charging drive management unit for power supply on the other hand.

[0019] By adopting the above technical solution, the circuit introduces a power management unit, which is responsible for providing stable power to the front-end management chip AFE2 and the main control module, and provides DC power to the charging drive management unit, ensuring that the entire BMS can obtain reliable power supply in different states. Compared with the traditional BMS method of directly drawing power from the battery, this design reduces the impact of battery voltage fluctuations on the power supply of the management chip, thereby improving the reliability of the system and reducing false protection caused by unstable power supply.

[0020] Preferably, the current detection signal input terminal of the front-end management chip AFE1 is connected to a shunt unit, and the shunt unit is located between the switch management module and the negative terminal of the battery module.

[0021] By adopting the above technical solution, a shunt unit is added to the current detection signal input end of the front-end management chip AFE1 to accurately measure the battery charging and discharging current, providing more accurate SOC calculation and overcurrent protection. Compared with the traditional current detection method, this solution uses a low-resistance and high-precision shunt to reduce measurement errors and improve the accuracy of overcurrent protection, thereby improving the overall safety of the system and optimizing the battery life.

[0022] Preferably, the reverse connection detection module includes an optocoupler U4 and a diode D3, the positive terminal of the light-emitting diode part of the optocoupler U4 is connected to the negative terminal of the battery core module, the negative terminal of the light-emitting diode part of the optocoupler U4 is connected to the positive terminal of the diode D3, the negative terminal of the diode D3 is connected to the positive terminal of the battery core module, the first conduction end of the transistor part of the optocoupler U4 is connected to the power supply, and the second conduction end of the transistor part of the optocoupler U4 serves as the signal output end of the reverse connection detection module.

[0023] By adopting the above technical solution, the reverse connection detection module of the circuit detects the voltage status between P / C- and the battery module in real time through optocoupler isolation. When the charger is reversely connected, the optocoupler U4 is turned on and sends a protection signal to the BMS to ensure that the charging path can be quickly disconnected when reversely connected to prevent damage to the BMS or charger. Compared with the traditional pure MCU software judgment reverse connection solution, optocoupler detection can achieve faster response speed at the hardware level and has stronger anti-interference ability, improving the safety and reliability of the system.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: This application introduces a reverse connection detection module. When the reverse connection detection module detects that the charger polarity is wrong, it immediately sends a signal to the detection signal input terminal of the BMS control system, so that the BMS control system responds to protection and sends a first enable signal to the switch drive module synchronously. At the same time, the enable signal output terminal of the BMS control system also provides an additional control signal to the switch drive module to ensure that the drive module correctly performs the protection operation. After receiving these signals, the switch drive module will further send a control instruction to the switch management module to quickly cut off the power supply circuit to prevent the wrong connection of the charger from damaging the battery or BMS system. It can quickly cut off the circuit to prevent the current from flowing back due to misoperation, and avoid thermal runaway, MOS tube breakdown or PCB overcurrent burning caused by reverse current entering the battery pack. In addition, the scheme establishes a multi-level protection logic between the BMS control system and the switch drive module, so that the system has a dual insurance mechanism of independent hardware detection + MCU logic judgment. Even when the MCU fails or the control logic is abnormal, the hardware can still ensure that the power supply path is cut off, thereby improving the safety and reliability of the entire system. The implementation of this reverse connection protection circuit enables the multi-string BMS charging system to operate more stably in complex application scenarios (such as electric vehicles, electric motorcycles, energy storage systems, etc.), and effectively reduces the risk of equipment damage caused by user misoperation or external factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a multi-string BMS charging reverse connection protection circuit in one embodiment of the present application.

[0026] Figure 2 This is a partial circuit structure diagram of a BMS control system and a power supply circuit in a multi-string BMS charging reverse connection protection circuit in one embodiment of the present application; Figure 3 It is a schematic diagram of a partial circuit structure of a discharge drive management unit in a multi-string BMS charging reverse connection protection circuit in one embodiment of the present application; Figure 4 This is a schematic diagram of a partial circuit structure of a charging drive management unit in a multi-string BMS charging reverse connection protection circuit in one embodiment of the present application; Figure 5 This is a schematic diagram of a partial circuit structure of a switch management module in a multi-string BMS charging reverse connection protection circuit in one embodiment of the present application; Figure 6 This is a partial circuit structure diagram of a reverse connection detection module in a multi-string BMS charging reverse connection protection circuit in one embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with the accompanying drawings.

[0028] In one embodiment, if Figure 1 As shown, the present application discloses a multi-string BMS charging reverse connection protection circuit, which includes a battery cell module, a BMS control system, a switch management module, a reverse connection detection module and a switch driving module. The battery cell module, the switch management module and the charger are connected in sequence to form a power supply circuit for powering the charger. The balanced signal output end of the battery cell module is connected to the balanced signal input end of the BMS control system, the drive signal output end of the BMS control system is connected to the drive signal input end of the switch driving module, the signal input end of the reverse connection detection module is connected to a common node in the power supply circuit, the signal output end of the reverse connection detection module is respectively connected to the detection signal input end of the BMS control system and the first enable signal input end of the switch driving module, the enable signal output end of the BMS control system is connected to the second enable signal input end of the switch driving module, and the enable signal output end of the switch driving module is connected to the enable signal input end of the switch management module to control the on and off of the switch management module.

[0029] In this embodiment, the circuit realizes automatic detection and protection of reverse charging through signal transmission between the battery module, BMS control system, switch management module, reverse connection detection module and switch drive module, ensuring the safe operation of the charger and battery. The battery module contains multiple battery cells connected in series, and provides a balanced signal output terminal, which is directly connected to the balanced signal input terminal of the BMS control system, so that the BMS control system can monitor the voltage imbalance inside the battery pack in real time and take a balanced strategy to adjust the battery cell voltage. The drive signal output terminal of the BMS control system is connected to the drive signal input terminal of the switch drive module, so that the BMS control system can send a control signal to the switch drive module to determine the switch state of the discharge or charging path. The signal input terminal of the reverse connection detection module is connected to the common node in the power supply circuit, which is used to monitor the voltage polarity and current direction in the power supply path in real time to ensure that the positive and negative poles of the charger are correctly connected. When the reverse connection detection module detects an abnormal reverse connection in the power supply circuit, its signal output terminal simultaneously sends a signal to the detection signal input terminal of the BMS control system and the first enable signal input terminal of the switch drive module to notify the system of a reverse connection event. After receiving the abnormal signal from the reverse connection detection module, the BMS control system immediately sends a signal to the second enable signal input terminal of the switch driver module to put it into protection mode to prevent incorrect charging. After receiving the signals from the reverse connection detection module and the BMS control system at the same time, the switch driver module will immediately control the on and off of the switch management module, and send a control signal to the enable signal input terminal of the switch management module through its enable signal output terminal, thereby closing the charging or discharging path and disconnecting the power supply circuit. The control logic of the entire system ensures that when the charger is connected in reverse, it can respond quickly and cut off the power supply path to avoid damage caused by reverse current entering the battery pack, and at the same time prevent the internal current of the charger from flowing back to the BMS system to cause circuit burning, thereby achieving reliable reverse charging protection.

[0030] In summary, by introducing the reverse connection detection module, when the reverse connection detection module detects that the charger polarity is wrong, it immediately sends a signal to the detection signal input terminal of the BMS control system, so that the BMS control system responds to protection, and simultaneously sends a first enable signal to the switch drive module. At the same time, the enable signal output terminal of the BMS control system also provides an additional control signal to the switch drive module to ensure that the drive module correctly performs the protection operation. After receiving these signals, the switch drive module will further send a control instruction to the switch management module to quickly cut off the power supply circuit to prevent the wrong connection of the charger from damaging the battery or BMS system. It can quickly cut off the circuit to prevent the current from flowing back due to misoperation, and avoid thermal runaway, MOS tube breakdown or PCB overcurrent burning caused by reverse current entering the battery pack. In addition, the solution establishes a multi-level protection logic between the BMS control system and the switch drive module, so that the system has a dual insurance mechanism of independent hardware detection + MCU logic judgment. Even when the MCU fails or the control logic is abnormal, the hardware can still ensure that the power supply path is cut off, thereby improving the safety and reliability of the entire system. The implementation of this reverse connection protection circuit enables the multi-string BMS charging system to operate more stably in complex application scenarios (such as electric vehicles, electric motorcycles, energy storage systems, etc.), and effectively reduces the risk of equipment damage caused by user misoperation or external factors.

[0031] Further, such as Figure 2 As shown, the BMS control system includes a power management front-end module and a main control module. The power management front-end module includes a passive balancing unit, a front-end management chip AFE1 and a front-end management chip AFE2. The balancing signal input end of the passive balancing unit is connected to the balancing signal output end of the battery cell module, the first balancing detection output end of the passive balancing unit is connected to the balancing detection input end of the front-end management chip AFE1, the second balancing detection output end of the passive balancing unit is connected to the balancing detection input end of the front-end management chip AFE2, the data communication end of the front-end management chip AFE1 is connected to the first data communication end of the main control module, the data communication end of the front-end management chip AFE2 is connected to the second data communication end of the main control module, the drive signal output end of the front-end management chip AFE1 is connected to the drive signal input end of the switch drive module, the detection signal input end of the main control module is connected to the signal output end of the reverse connection detection module, and the enable signal output end of the main control module is connected to the second enable signal input end of the switch drive module.

[0032] In this embodiment, the BMS control system consists of a power management front-end module and a main control module, wherein the functions of the power management front-end module are mainly battery voltage balancing, data acquisition and switch control, while the main control module is responsible for the analysis of the overall system status, the detection of abnormal conditions and the management of enable signals. The battery balancing adjustment is performed by the balancing control unit inside the battery management system, which receives the balancing feedback signal from the battery cell part and transmits it to the analog front-end management chip for subsequent analysis of the voltage difference between different battery cells and balanced discharge. The data acquisition function of the analog front-end management chip ensures real-time monitoring of the battery voltage and current, and transmits the collected data to the main control module for decision-making on charge and discharge management. In addition to being responsible for monitoring the battery cell, the analog front-end management chip also undertakes the task of driving the discharge path, and its driving signal directly controls the discharge management unit to ensure that the battery system can perform the discharge task in accordance with the normal working mode. In addition to receiving battery monitoring data, the main control module also establishes a signal connection with the reverse connection detection circuit. When the charger is detected to be connected in reverse or other abnormal conditions, the abnormal signal is received by the main control module and the protection mechanism is triggered to ensure that the charging path will not cause damage to the battery pack or charger due to misconnection. After detecting the reverse connection, the main control module will immediately send a control signal to the switch drive unit to disconnect the charging management path, thereby preventing reverse current from entering the battery pack and avoiding the impact of high voltage or short circuit on the system. The entire control logic ensures that the analog front-end management chip can independently complete battery balancing, cell status monitoring, and discharge path control, while the main control module focuses on data analysis, charging status management, and abnormal protection, so that the system has a complete battery management capability to ensure the safety and stability of the battery pack under various operating conditions; The introduction of the front-end management chip AFE1 and the front-end management chip AFE2 is to improve the monitoring accuracy, balancing efficiency and overall reliability of the multi-string battery management system. Since the multi-string battery system usually contains a large number of cells, the voltage, current and temperature of each cell need to be monitored in real time to ensure the safe operation and performance optimization of the battery pack. However, the number of channels of a single front-end management chip AFE is limited and it is impossible to efficiently manage all cells. Therefore, multiple front-end management chips AFE chips are required to work together. The front-end management chip AFE1 and the front-end management chip AFE2 are responsible for the monitoring and balancing control of different battery packs, respectively, so that the voltage data of the cells can be collected independently and transmitted to the main control module through data communication, so that the main control module can perform unified analysis and management. In addition, the front-end management chip AFE1 is not only responsible for monitoring the battery status, but also directly participates in driving the discharge path, while the front-end management chip AFE2 focuses on collecting the voltage balancing information of another part of the battery. This division of labor ensures that the system can quickly and accurately perform balancing adjustment when processing multiple strings of batteries, and can respond quickly when an abnormality occurs, triggering the protection mechanism in time to avoid system failures or safety hazards caused by cell imbalance or abnormal voltage.

[0033] Further, such as Figure 2-Figure 5 As shown, the switch management module includes a charging switch module and a discharging switch module which are sequentially connected to the power supply circuit, and the switch driving module includes a discharging driving management unit and a charging driving management unit. The enable signal output end of the discharging driving management unit is connected to the enable signal input end of the discharging switch module, and the enable signal output end of the charging driving management unit is connected to the enable signal input end of the charging switch module. Both the discharging driving management unit and the charging driving management unit are controlled by the enable signal of the front-end management chip AFE1, thereby controlling the on and off of the charging switch module or the discharging switch module.

[0034] In this embodiment, the charge and discharge paths can be independently controlled according to different working states, wherein the charging switch module and the discharging switch module are sequentially connected to the power supply circuit to ensure that the energy transmission of the battery module can be carried out in the correct circuit path. The switch drive module controls the on and off of the discharge switch module and the charging switch module respectively through the discharge drive management unit and the charging drive management unit, so that the system can perform correct current direction management in different modes. The enable signal output end of the discharge drive management unit is directly connected to the enable signal input end of the discharge switch module, which means that when the discharge drive management unit receives the correct drive signal, it will control the conduction or shutdown of the discharge switch module through the connection relationship to ensure that the battery system can provide stable power output when discharge is required. Similarly, the enable signal output end of the charging drive management unit is connected to the enable signal input end of the charging switch module, so that it can control the switch state of the charging path to ensure that when the charging demand is generated, the current can flow from the charger to the battery pack, and when the charging is completed or an abnormal situation occurs, the charging path can be disconnected in time. The operation of the entire switch management module depends on the control signal provided by the front-end management chip AFE1. The enable signal of AFE1 not only determines the working state of the discharge drive management unit, but also directly affects the switch control logic of the charging drive management unit. When AFE1 sends a corresponding enable signal according to the voltage state of the battery module, the balancing requirements and the current working mode of the system, the discharge drive management unit and the charging drive management unit will receive the signal respectively, and perform the corresponding discharge or charging control, so that the charging switch module or the discharge switch module can switch as required. The entire control logic ensures that in different operating modes, the charging and discharging paths can operate as expected, and can respond quickly in abnormal situations, cutting off the corresponding paths to protect the safety and reliability of the system, while ensuring that the battery system has accurate charge and discharge management capabilities when working efficiently.

[0035] Further, such as Figure 3 As shown, the discharge drive management unit includes a drive chip U2, a transistor Q4 and a resistor R14. The drive signal input end of the drive chip U2 is connected to the drive signal output end of the front-end management chip AFE1, the common node between the drive signal input end of the drive chip U2 and the drive signal output end of the front-end management chip AFE1 is connected to the first conduction end of the transistor Q4, the second conduction end of the transistor Q4 is grounded, the controlled end of the transistor Q4 is connected to the signal output end of the reverse connection detection module, the enable signal input end of the drive chip U2 is connected to the enable signal output end of the main control module, the output end of the drive chip U2 is connected to the first end of the resistor R14, the second end of the resistor R14 is connected to the enable signal input end of the discharge switch module, and the common node between the output end of the drive chip U2 and the first end of the resistor R14 is connected to the power input end of the charging drive management unit.

[0036] In this embodiment, the discharge drive management unit realizes precise control of the discharge switch module through the synergistic effect of the driver chip U2, the transistor Q4 and the resistor R14, and responds quickly when a reverse connection occurs to ensure the safe operation of the battery system. The drive signal input end of the driver chip U2 is connected to the drive signal output end of the front-end management chip AFE1, so that the front-end management chip AFE1 can directly provide a discharge control signal to the driver chip U2, thereby determining whether the discharge path is turned on. In order to ensure the stability of signal transmission, a common node is formed between the drive signal input end of the driver chip U2 and the drive signal output end of the front-end management chip AFE1, and the common node is further connected to the first conduction end of the transistor Q4, so that the transistor Q4 can synchronously sense the state of the drive signal. The second conduction end of the transistor Q4 is directly grounded to form a control path, so that when its controlled end receives the abnormal signal transmitted by the signal output end of the reverse connection detection module, the transistor Q4 can be quickly turned on, thereby lowering the voltage level of the common node, indirectly affecting the signal processing logic of the driver chip U2. The enable signal input terminal of the driver chip U2 is connected to the enable signal output terminal of the main control module, which means that the main control module can actively control the enable state of the driver chip U2 during the operation of the system, so that it is activated when discharge is required, and the discharge path can be quickly disabled when an abnormal situation is detected. The output terminal of the driver chip U2 is connected to the first end of the resistor R14, which is used for signal current limiting to ensure the stability of the output signal. At the same time, the second end of the resistor R14 is connected to the enable signal input terminal of the discharge switch module, so that the discharge switch module can determine its own on or off state according to the control signal of the driver chip U2. At the same time, the common node between the output terminal of the driver chip U2 and the first end of the resistor R14 is also connected to the power input terminal of the charging drive management unit, which enables the charging drive management unit to share the voltage state of the common node, ensure the stability of the power supply in the discharge mode, and perform effective power management and path switching between different working modes. The entire design ensures that the discharge switch module can be turned on according to system requirements under normal circumstances. At the same time, when the charger is detected to be reversely connected or other abnormal conditions are detected, the reverse connection detection module suppresses the drive signal of the driver chip U2 through the control of the transistor Q4, and then closes the discharge path, thereby protecting the battery system and avoiding continuous conduction of the discharge path due to incorrect connection or circuit abnormality, ultimately improving the safety and reliability of the entire system.

[0037] Further, such as Figure 4As shown, the charging drive management unit includes an acceleration shutdown subunit, a MOS tube M1, a MOS tube Q1, a resistor R2, a resistor R3, a resistor R5 and a resistor R6. The first conduction end of the MOS tube M1 is connected to a DC power supply, the second conduction end of the MOS tube M1 is connected to a first end of the acceleration shutdown subunit, the second end of the acceleration shutdown subunit is connected to an enable signal input end of the charging switch module, the first end of the resistor R2 is connected to a power output end of the discharge drive management unit, a common node between a first end of the resistor R3 and a controlled end of the MOS tube M1 is connected to a second end of the resistor R2, the second end of the resistor R3 is connected to a first conduction end of the MOS tube Q1, the second conduction end of the MOS tube Q1 is grounded, the enable signal output end of the front-end management chip AFE1 is connected to a first end of the resistor R5, the second end of the resistor R5 is connected to the controlled end of the MOS tube Q1, the second end of the resistor R5 and the controlled end of the MOS tube Q1 are connected to a first end of the resistor R6, and the second end of the resistor R6 is grounded.

[0038] In this embodiment, the charging drive management unit realizes precise control of the charging switch module through the coordinated action of the acceleration shutdown subunit, MOS tube M1, MOS tube Q1, resistor R2, resistor R3, resistor R5 and resistor R6, so that the charging path can be quickly turned on when needed and quickly disconnected in abnormal situations to prevent safety risks caused by reverse connection of the charger or overcharging of the battery. The first conduction end of the MOS tube M1 is directly connected to the DC power supply, so that it has power supply capability. When the MOS tube M1 is turned on, it can guide the current to the charging management circuit of the subsequent stage, and the second conduction end of the MOS tube M1 is connected to the first end of the acceleration shutdown subunit. This connection ensures that when the MOS tube M1 is in the on state, the acceleration shutdown subunit can obtain the correct control signal, thereby accurately managing the charging path. The second end of the acceleration shutdown subunit is directly connected to the enable signal input end of the charging switch module, which means that the acceleration shutdown subunit will maintain the stability of the switch signal during normal charging, and can respond quickly when it needs to be turned off, so that the charging switch module quickly cuts off the current to avoid malfunction or damage to the battery pack caused by residual current in the charging path. The first end of the resistor R2 is connected to the power output end of the discharge drive management unit. This connection ensures that the energy management of the discharge path can synchronously affect the charge drive management unit, so that the charge and discharge control logic can operate in coordination, avoiding the charge and discharge paths from being turned on at the same time under erroneous conditions, thereby preventing the risk of short circuit. The first end of the resistor R3 is connected to the controlled end of the MOS tube M1, and forms a common connection with the second end of the resistor R2 at this node. This structure ensures that when the control signal of the MOS tube M1 is adjusted, the power state of the discharge drive management unit can be fed back at the same time, so that the charge and discharge management unit will not conflict when switching states. The second end of the resistor R3 is connected to the first conduction end of the MOS tube Q1, so that the MOS tube Q1 can play a signal transmission role in the control logic. When the potential of the resistor R3 changes, the conduction state of the MOS tube Q1 can be adjusted accordingly to ensure that in different working modes, the charging path can be accurately switched according to current needs. The second conduction end of the MOS tube Q1 is grounded, so that it can form a complete conduction path when triggered, ensuring that the system can quickly shut down the charging path when needed to prevent mischarging due to abnormal signals. The enable signal output end of the front-end management chip AFE1 is connected to the first end of the resistor R5, so that the control signal of AFE1 can directly affect the working state of the MOS tube Q1, ensuring that when AFE1 detects the charging demand, Q1 can be correctly driven to enter the expected working mode. At the same time, the second end of the resistor R5 is connected to the controlled end of the MOS tube Q1, so that the control signal of AFE1 can be stably transmitted to Q1 and further affect the switching state of the charging path.The common node between the second end of resistor R5 and the controlled end of MOS tube Q1 is also connected to the first end of resistor R6. This connection enables resistor R6 to play a signal voltage dividing and stabilizing role in the circuit, ensuring that the controlled signal of MOS tube Q1 can remain stable under different load conditions. The second end of resistor R6 is grounded to form a complete potential distribution, so that the system can smoothly transition when the signal is switched, avoiding transient voltage fluctuations from affecting the normal operation of the charging path. The entire charging drive management unit ensures that under normal circumstances, the charging path can be turned on in the expected mode, and when reverse connection, overvoltage or other abnormal conditions are detected, the charging path can be quickly shut down to prevent the battery or charger from being damaged by abnormal current, ensuring the stability and safety of the entire BMS system in various charging scenarios.

[0039] Further, such as Figure 4 As shown, the acceleration shutdown subunit includes a transistor Q2, a transistor Q3, a resistor R4, a resistor R7, a diode D1 and a diode D2, the positive terminal of the diode D2 is connected to the second conduction end of the MOS tube M1, the negative terminal of the diode D2 is connected to the positive terminal of the diode D1, the negative terminal of the diode D1 is connected to the enable signal input end of the charging switch module, the common node between the negative terminal of the diode D1 and the enable signal input end of the charging switch module is connected to the first end of the resistor R4, the second end of R4 is connected to the first conduction end of the transistor Q2, the second conduction end of the transistor Q2 is connected to the controlled end of the transistor Q3, the common node between the negative terminal of the diode D2 and the positive terminal of the diode D1 is respectively connected to the first end of the resistor R7, the controlled end of the transistor Q2 and the first conduction end of the transistor Q3, the second end of the resistor R7 is grounded, and the second conduction end of the transistor Q3 is grounded.

[0040] In this embodiment, the accelerated shutdown subunit is composed of a transistor Q2, a transistor Q3, a resistor R4, a resistor R7, a diode D1 and a diode D2. Its core function is to accelerate the shutdown process of the charging path, so that the charging switch module can quickly enter the cut-off state when it needs to be turned off, avoiding the residual current in the charging path caused by the shutdown delay of the MOS tube, thereby improving the response speed and protection capability of the system. The positive terminal of the diode D2 is connected to the second conduction end of the MOS tube M1, so that when the MOS tube M1 is turned on, the diode D2 can be turned on synchronously and transmit the subsequent signal to the control part of the charging path. The negative terminal of the diode D2 is connected to the positive terminal of the diode D1, so that the diode D1 and the diode D2 form a series relationship. When the diode D2 is turned on, the diode D1 can be turned on accordingly, so that the signal is transmitted to the enable signal input end of the charging switch module. The cathode end of the diode D1 is directly connected to the enable signal input end of the charging switch module, ensuring that the control end of the charging switch module can accurately receive the shutdown control signal, so that the MOS tube quickly enters the cut-off state when the charging path needs to be closed, avoiding charging residual current due to the delay effect of the MOS tube. The common node between the cathode end of the diode D1 and the enable signal input end of the charging switch module is simultaneously connected to the first end of the resistor R4, so that the potential change of the node can affect the current distribution of the resistor R4, providing a stable voltage reference for subsequent signal processing. The second end of the resistor R4 is connected to the first conduction end of the transistor Q2, so that when the current on the resistor R4 changes, the transistor Q2 can synchronously sense and enter the corresponding conduction or cut-off state, realizing the amplification and transmission of the shutdown signal. The second conduction end of transistor Q2 is connected to the controlled end of transistor Q3, so that the conduction state of transistor Q2 can directly affect the working state of transistor Q3. When transistor Q2 is turned on, the controlled end of transistor Q3 is pulled down, so that transistor Q3 enters the conduction state, further enhancing the execution strength of the shutdown signal, and ensuring that the charging path can be quickly cut off. The common node between the negative terminal of diode D2 and the positive terminal of diode D1 is respectively connected to the first end of resistor R7, the controlled end of transistor Q2 and the first conduction end of transistor Q3, so that the potential of the common node can simultaneously affect the working state of multiple components, ensuring the consistency and synchronization of signal transmission of the entire shutdown loop. The second end of resistor R7 is grounded, so that it can provide stable current distribution and prevent the control signal from being distorted due to floating potential during signal transmission. The second conduction end of the transistor Q3 is grounded, so that when the transistor Q3 is turned on, a complete conduction path can be formed, thereby quickly lowering the potential of the enable signal input end of the charging switch module, ensuring that the charging path can be quickly cut off when needed, preventing the instability of the charging system due to incomplete shutdown of the MOS tube.The design of the entire accelerated shutdown subunit ensures that the charging path can quickly complete signal transmission when entering the shutdown state, avoiding abnormal system operation due to residual charging current. At the same time, it improves the BMS's ability to respond to emergencies, making the charging process safer and more reliable.

[0041] Further, such as Figure 5 As shown, the discharge switch module includes MOS tubes MD1 and MOS tube MD2, and the charging switch module includes MOS tubes MC1 and MOS tubes MC2. The first conductive end of MOS tube MD1 is connected to the negative end of the battery cell module, the second conductive end of MOS tube MD1 is connected to the first conductive end of MOS tube MC1, the second conductive end of MOS tube MC1 is connected to the negative end of the charger, the first conductive end of MOS tube MD2 is connected to the negative end of the battery cell module, the second conductive end of MOS tube MD2 is connected to the first conductive end of MOS tube MC2, and the second conductive end of MOS tube MC2 is connected to the negative end of the charger, the enable signal output end of the discharge drive management unit is respectively connected to the controlled end of MOS tube MD1 and the controlled end of MOS tube MD2, and the enable signal output end of the charging drive management unit is respectively connected to the controlled end of MOS tube MC1 and the controlled end of MOS tube MC2.

[0042] In this embodiment, the overall design of the discharge switch module MOS tube MD1 and MOS tube MD2 and the charging switch module MOS tube MC1 and MOS tube MC2 ensures that the charging and discharging paths of the battery module can be independently controlled in different working modes, so that the battery management system can maintain safe and reliable current transmission during charging or discharging, and quickly cut off the corresponding path in abnormal situations to avoid safety risks caused by misoperation. The first conduction end of the discharge switch module MOS tube MD1 is directly connected to the negative end of the battery module, so that when the discharge path needs to be opened, the battery can release electrical energy to the external load through the conduction end. The second conduction end of the MOS tube MD1 is connected to the first conduction end of the charging switch module MOS tube MC1, so that the node can assume the role of signal transmission in different modes, ensuring that the charging and discharging paths can be correctly switched. The second conduction end of the MOS tube MC1 is connected to the negative end of the charger, so that when the charging mode is turned on, the charger can provide charging current to the battery through the conduction end, ensuring that the charging path is turned on under controlled conditions, and can be quickly cut off when it needs to be disconnected to prevent abnormal current from flowing into the battery. The first conduction end of the MOS tube MD2 of the discharge switch module is also connected to the negative terminal of the battery module, so that MD2 can bear the current shunting function in parallel in the discharge mode, ensuring that the discharge path can provide a more stable current output, and avoiding a single MOS tube from bearing too much current, causing the system to heat up or reduce efficiency. The second conduction end of the MOS tube MD2 is connected to the first conduction end of the MOS tube MC2 of the charging switch module, so that the current can flow according to the established path in different modes and maintain a stable transition state when the mode is switched. The second conduction end of the MOS tube MC2 is connected to the negative terminal of the charger, so that the charging path can stably transmit current during normal operation and can be quickly cut off in abnormal conditions to prevent overcharging or short circuit. The enable signal output end of the discharge drive management unit is respectively connected to the controlled end of the MOS tube MD1 of the discharge switch module and the controlled end of the MOS tube MD2 of the discharge switch module, so that when the system is in the discharge mode, the discharge drive management unit can provide a corresponding enable signal to turn on MD1 and MD2, thereby establishing a discharge path, so that the current of the battery can be smoothly released to the external load. The enable signal output end of the charging drive management unit is respectively connected to the controlled end of the charging switch module MOS tube MC1 and the controlled end of the charging switch module MOS tube MC2, so that when the system enters the charging mode, the charging drive management unit can provide a correct enable signal to turn on MC1 and MC2, thereby establishing a charging path, so that the current of the charger can enter the battery module according to the controlled path, and realize safe and reliable charging management.The entire control logic ensures that the MOS tubes of the charging switch module and the discharging switch module can switch correctly in different modes to avoid the risk of short circuit caused by the simultaneous conduction of the charging and discharging paths. At the same time, when an abnormal situation is detected, the corresponding path can be quickly closed, so that the battery management system has complete safety protection capabilities while operating efficiently.

[0043] Further, such as Figure 2 As shown, the power management front-end module also includes a power management unit. The power input end of the power management unit is connected to the positive end of the battery cell module. The power output end of the power management unit outputs power to the front-end management chip AFE2 and the main control module for power supply on the one hand, and converts it into DC power and outputs it to the charging drive management unit for power supply on the other hand.

[0044] In this embodiment, the power output end of the power management unit directly provides working power to the front-end management chip AFE2 and the main control module, ensuring that AFE2 can stably perform the battery cell voltage, current and balance management tasks, while enabling the main control module to continuously perform data analysis, status monitoring and execution of charge and discharge control strategies, thereby maintaining the normal operation of the entire battery management system. On the other hand, the power management unit also has an electric energy conversion function, converting the input electric energy into a DC power supply that meets the working requirements of the charging drive management unit, and transmitting it to the charging drive management unit.

[0045] Further, such as Figure 2 As shown, the current detection signal input end of the front-end management chip AFE1 is connected to a shunt unit, and the shunt unit is located between the switch management module and the negative terminal of the battery module.

[0046] In this embodiment, the current detection signal input end of the front-end management chip AFE1 is connected to the shunt unit, so that AFE1 can accurately monitor the charge and discharge current of the battery system and provide key data for subsequent current protection, energy management and SOC (state of charge) calculation. The shunt unit is located between the switch management module and the negative terminal of the battery module, so that all charge and discharge currents flowing through the battery pack must pass through the shunt unit. This arrangement ensures that AFE1 can accurately measure the current flowing into or out of the battery module to avoid data errors caused by local current shunts. The shunt unit introduces a low-resistance and high-precision detection resistor in the current path to generate a small voltage drop when the current passes through. AFE1 can collect the voltage drop in real time and calculate the current size based on the known resistance value, thereby monitoring the working status of the entire system. In the discharge mode, AFE1 can detect the size of the discharge current and evaluate the current battery power output in combination with the battery voltage data. At the same time, in the charging mode, AFE1 can monitor the charging current entering the battery pack in real time to ensure that the charging process meets the set safety parameters and prevent overcurrent or abnormal charging. In addition, based on the data from the shunt unit, AFE1 can calculate the cumulative charge and discharge amount of the battery pack, providing accurate input data for SOC estimation, so that the main control module can adjust the charge and discharge strategy according to the actual remaining power of the battery, optimizing battery life and system operation efficiency. The current monitoring capability of AFE1 can also be combined with the safety protection mechanism. When overcurrent, short circuit or abnormal current fluctuation is detected, AFE1 can quickly send a protection signal to the switch drive management unit, so that the discharge switch module or the charging switch module immediately cuts off the current path to prevent the system from being damaged due to current overload. The reasonable layout of the shunt unit ensures that AFE1 can perform high-precision measurements of the current flow of the entire battery management system, providing a solid foundation for system safety, energy management, and charge and discharge optimization.

[0047] Further, such as Figure 6 As shown, the reverse connection detection module includes an optocoupler U4 and a diode D3, the positive terminal of the light-emitting diode part of the optocoupler U4 is connected to the negative terminal of the battery module, the negative terminal of the light-emitting diode part of the optocoupler U4 is connected to the positive terminal of the diode D3, the negative terminal of the diode D3 is connected to the positive terminal of the battery module, the first conduction end of the transistor part of the optocoupler U4 is connected to the power supply, and the second conduction end of the transistor part of the optocoupler U4 serves as the signal output end of the reverse connection detection module.

[0048] In this embodiment, the reverse connection detection module is composed of an optocoupler U4 and a diode D3. Its core function is to detect whether the positive and negative poles of the charger are correctly connected, and to quickly send a protection signal to the system when reverse connection occurs, so as to avoid damage to the battery management system, the battery module or the charger due to the wrong direction of the charging current. The positive terminal of the light-emitting diode part of the optocoupler U4 is directly connected to the negative terminal of the battery module, so that it can maintain an appropriate bias voltage under normal working conditions, and when the charging path is correctly connected, the circuit can maintain a stable state. The negative terminal of the light-emitting diode part of the optocoupler U4 is connected to the positive terminal of the diode D3, so that the diode D3 can provide a voltage detection reference when the charger is connected, and the negative terminal of the diode D3 is connected to the positive terminal of the battery module, thereby forming a polarity detection path in the circuit, so that the system can sense the connection status of the charger. The role of the diode D3 is to prevent reverse current from entering the battery module. When the charger is correctly connected, D3 remains normally turned on, so that the light-emitting diode part of the optocoupler U4 can obtain an appropriate drive current, ensuring that the transistor part of the optocoupler U4 remains in a normal working state. However, when the positive and negative poles of the charger are connected in reverse, the polarity of the diode D3 prevents the normal flow of current, causing the light-emitting diode part of the optocoupler U4 to be unable to conduct normally, thereby affecting the working state of the triode part of the optocoupler U4. The first conduction end of the triode part of the optocoupler U4 is connected to the power supply of the system, so that it can maintain operation under normal circumstances, and the second conduction end serves as the signal output end of the reverse connection detection module. When the internal triode of the optocoupler U4 switches due to the change in the conduction state of the light-emitting diode part of the optocoupler, the level of the signal output end will also change accordingly. Since the triode part of the optocoupler U4 will enter the off state in the reverse connection state, the signal output end will produce a significant level change, so the signal output end can be used by other modules of the system to identify whether the current charging path is correct. Once the signal output end of the reverse connection detection module transmits an abnormal signal to the main control module or the switch drive module, the BMS system will respond quickly, immediately turn off the charging switch module, cut off the charging path, and prevent the wrong wiring from causing current backflow and damaging the charger or battery pack. This design utilizes the electrical isolation characteristics provided by the optocoupler U4 to isolate the reverse connection detection signal from the main control circuit, improving the system's anti-interference ability. At the same time, the unidirectional conduction characteristics of the diode D3 ensure that the battery module can work stably in normal charging mode, and can quickly trigger the protection mechanism when reverse connection is detected, ensuring the safety and reliability of the entire charging management system.

[0049] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A multi-string BMS charging reverse connection protection circuit, characterized in that: The multi-string BMS charging reverse connection protection circuit includes a battery cell module, a BMS control system, a switch management module, a reverse connection detection module and a switch driving module. The battery cell module, the switch management module and the charger are connected in sequence to form a power supply circuit for powering the charger. The balanced signal output end of the battery cell module is connected to the balanced signal input end of the BMS control system, the drive signal output end of the BMS control system is connected to the drive signal input end of the switch driving module, the signal input end of the reverse connection detection module is connected to a common node in the power supply circuit, the signal output end of the reverse connection detection module is respectively connected to the detection signal input end of the BMS control system and the first enable signal input end of the switch driving module, the enable signal output end of the BMS control system is connected to the second enable signal input end of the switch driving module, and the enable signal output end of the switch driving module is connected to the enable signal input end of the switch management module to control the on and off of the switch management module.

2. A multi-string BMS charging reverse connection protection circuit according to claim 1, characterized in that: The BMS control system includes a power management front-end module and a main control module. The power management front-end module includes a passive balancing unit, a front-end management chip AFE1 and a front-end management chip AFE2. The balancing signal input end of the passive balancing unit is connected to the balancing signal output end of the battery cell module, the first balancing detection output end of the passive balancing unit is connected to the balancing detection input end of the front-end management chip AFE1, the second balancing detection output end of the passive balancing unit is connected to the balancing detection input end of the front-end management chip AFE2, the data communication end of the front-end management chip AFE1 is connected to the first data communication end of the main control module, the data communication end of the front-end management chip AFE2 is connected to the second data communication end of the main control module, the drive signal output end of the front-end management chip AFE1 is connected to the drive signal input end of the switch drive module, the detection signal input end of the main control module is connected to the signal output end of the reverse connection detection module, and the enable signal output end of the main control module is connected to the second enable signal input end of the switch drive module.

3. A multi-string BMS charging reverse connection protection circuit according to claim 2, characterized in that: The switch management module includes a charging switch module and a discharging switch module which are sequentially connected to the power supply circuit; the switch driving module includes a discharging driving management unit and a charging driving management unit; the enable signal output end of the discharging driving management unit is connected to the enable signal input end of the discharging switch module; the enable signal output end of the charging driving management unit is connected to the enable signal input end of the charging switch module; the discharging driving management unit and the charging driving management unit are both controlled by the enable signal of the front-end management chip AFE1, thereby controlling the on and off of the charging switch module or the discharging switch module.

4. A multi-string BMS charging reverse connection protection circuit according to claim 3, characterized in that: The discharge drive management unit includes a drive chip U2, a transistor Q4 and a resistor R14. The drive signal input end of the drive chip U2 is connected to the drive signal output end of the front-end management chip AFE1, the common node between the drive signal input end of the drive chip U2 and the drive signal output end of the front-end management chip AFE1 is connected to the first conduction end of the transistor Q4, the second conduction end of the transistor Q4 is grounded, the controlled end of the transistor Q4 is connected to the signal output end of the reverse connection detection module, the enable signal input end of the drive chip U2 is connected to the enable signal output end of the main control module, the output end of the drive chip U2 is connected to the first end of the resistor R14, the second end of the resistor R14 is connected to the enable signal input end of the discharge switch module, and the common node between the output end of the drive chip U2 and the first end of the resistor R14 is connected to the power input end of the charging drive management unit.

5. A multi-string BMS charging reverse connection protection circuit according to claim 3, characterized in that: The charging drive management unit includes an acceleration shutdown subunit, a MOS tube M1, a MOS tube Q1, a resistor R2, a resistor R3, a resistor R5 and a resistor R6. The first conduction end of the MOS tube M1 is connected to a DC power supply, the second conduction end of the MOS tube M1 is connected to the first end of the acceleration shutdown subunit, the second end of the acceleration shutdown subunit is connected to the enable signal input end of the charging switch module, the first end of the resistor R2 is connected to the power output end of the discharge drive management unit, the common node between the first end of the resistor R3 and the controlled end of the MOS tube M1 is connected to the second end of the resistor R2, the second end of the resistor R3 is connected to the first conduction end of the MOS tube Q1, the second conduction end of the MOS tube Q1 is grounded, the enable signal output end of the front-end management chip AFE1 is connected to the first end of the resistor R5, the second end of the resistor R5 is connected to the controlled end of the MOS tube Q1, the common node between the second end of the resistor R5 and the controlled end of the MOS tube Q1 is connected to the first end of the resistor R6, and the second end of the resistor R6 is grounded.

6. A multi-string BMS charging reverse connection protection circuit according to claim 5, characterized in that: The acceleration shutdown subunit includes a transistor Q2, a transistor Q3, a resistor R4, a resistor R7, a diode D1 and a diode D2, wherein the positive terminal of the diode D2 is connected to the second conduction end of the MOS transistor M1, the negative terminal of the diode D2 is connected to the positive terminal of the diode D1, the negative terminal of the diode D1 is connected to the enable signal input end of the charging switch module, the common node between the negative terminal of the diode D1 and the enable signal input end of the charging switch module is connected to the first end of the resistor R4, the second end of R4 is connected to the first conduction end of the transistor Q2, the second conduction end of the transistor Q2 is connected to the controlled end of the transistor Q3, the common node between the negative terminal of the diode D2 and the positive terminal of the diode D1 is respectively connected to the first end of the resistor R7, the controlled end of the transistor Q2 and the first conduction end of the transistor Q3, the second end of the resistor R7 is grounded, and the second conduction end of the transistor Q3 is grounded.

7. A multi-string BMS charging reverse connection protection circuit according to claim 3, characterized in that: The discharge switch module includes a MOS tube MD1 and a MOS tube MD2, and the charge switch module includes a MOS tube MC1 and a MOS tube MC2. The first conduction end of the MOS tube MD1 is connected to the negative end of the battery cell module, the second conduction end of the MOS tube MD1 is connected to the first conduction end of the MOS tube MC1, the second conduction end of the MOS tube MC1 is connected to the negative end of the charger, the first conduction end of the MOS tube MD2 is connected to the negative end of the battery cell module, the second conduction end of the MOS tube MD2 is connected to the first conduction end of the MOS tube MC2, and the second conduction end of the MOS tube MC2 is connected to the negative end of the charger, the enable signal output end of the discharge drive management unit is respectively connected to the controlled end of the MOS tube MD1 and the controlled end of the MOS tube MD2, and the enable signal output end of the charge drive management unit is respectively connected to the controlled end of the MOS tube MC1 and the controlled end of the MOS tube MC2.

8. A multi-string BMS charging reverse connection protection circuit according to claim 2, characterized in that: The power management front-end module also includes a power management unit, and the power input end of the power management unit is connected to the positive end of the battery cell module. The power output end of the power management unit outputs power to the front-end management chip AFE2 and the main control module for power supply on the one hand, and converts it into DC power and outputs it to the charging drive management unit for power supply on the other hand.

9. A multi-string BMS charging reverse connection protection circuit according to claim 2, characterized in that: The current detection signal input end of the front-end management chip AFE1 is connected to a shunt unit, and the shunt unit is located between the switch management module and the negative terminal of the battery module.

10. A multi-string BMS charging reverse connection protection circuit according to claim 1, characterized in that: The reverse connection detection module includes an optocoupler U4 and a diode D3, the positive terminal of the light-emitting diode part of the optocoupler U4 is connected to the negative terminal of the battery core module, the negative terminal of the light-emitting diode part of the optocoupler U4 is connected to the positive terminal of the diode D3, the negative terminal of the diode D3 is connected to the positive terminal of the battery core module, the first conduction end of the triode part of the optocoupler U4 is connected to the power supply, and the second conduction end of the triode part of the optocoupler U4 serves as the signal output end of the reverse connection detection module.

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