Battery charging and discharging management circuit supporting bidirectional current limiting

Abstract

The utility model discloses a battery charging and discharging management circuit supporting bidirectional current limiting. The battery charging and discharging management circuit comprises a power supply bus; the charging switch, the discharging switch and the current collector are connected to a power bus in series; the output end of the charging and discharging driving circuit is connected with the charging switch and the discharging switch; one end of the regulation and control circuit is connected with the current collector, and the other end is connected with the input end of the charging and discharging driving circuit; the current limiting circuit comprises a switch circuit and a switch driving circuit, the switch circuit is connected with the charging switch and the discharging switch in parallel, and the control end of the switch circuit is connected with the switch driving circuit; the regulation and control circuit further controls the state of the switch driving circuit based on the collected information so as to regulate and control the charging current or the discharging current flowing through the switch circuit. According to the management circuit, the current limiting mode can be dynamically switched in a charging and discharging bidirectional path, complex inductors, capacitors and multi-stage switching devices in a traditional scheme are omitted, the number of elements and the size of the circuit are remarkably reduced, the hardware cost is reduced, and the overall energy efficiency is high.

Description

Technical Field

[0001] This utility model relates to the field of battery charge and discharge management technology, and in particular to a battery charge and discharge management circuit that supports bidirectional current limiting. Background Technology

[0002] With the widespread application of lithium batteries in electric vehicles, energy storage systems, and portable devices, their charge and discharge management technologies face higher requirements for safety and efficiency. Current mainstream current limiting solutions rely on DC / DC converter topologies, such as using Buck-Boost circuits combined with inductors, capacitors, and PWM controllers to achieve current control.

[0003] Traditional DC / DC current limiting solutions require inductors, capacitors, freewheeling diodes, and multiple switching devices, resulting in bulky circuits and high costs. Moreover, most solutions only limit current in one direction, either charging or discharging, making it difficult to meet the needs of bidirectional energy exchange scenarios. Utility Model Content

[0004] The purpose of this invention is to provide a battery charge and discharge management circuit that achieves bidirectional dynamic regulation of charging and discharging current while simplifying the topology.

[0005] To achieve the above objectives, this utility model provides a battery charge / discharge management circuit supporting bidirectional current limiting, comprising:

[0006] The power bus has one end connected to the main electrode of the battery pack and the other end used to connect to the load.

[0007] A charging switch, a discharging switch, and a current collector are connected in series on the power bus.

[0008] A charge / discharge drive circuit, the output of which is connected to the charging switch and the discharging switch;

[0009] A control circuit, one end of which is connected to the current acquisition device to acquire the current information acquired by the current acquisition device, and the other end of the control circuit is connected to the input terminal of the charge and discharge drive circuit. The control circuit is used to control the state of the charging switch and the discharging switch by means of the charge and discharge drive circuit based on the acquired information.

[0010] The current limiting circuit includes a switching circuit and a switching drive circuit. The switching circuit is connected in parallel with the charging switch and the discharging switch. The control terminal of the switching circuit is connected to the switching drive circuit. The switching drive circuit is used to control the current state on the switching circuit. The control terminal of the switching drive circuit is connected to the regulating circuit.

[0011] The control circuit also controls the state of the switch drive circuit based on the collected information, so as to regulate the charging current or discharging current flowing through the switch circuit.

[0012] Preferably, the control circuit is also connected to the battery pack to collect the state information of the battery pack, so that the control circuit can control the state of the charging switch and the discharging switch according to the state of the battery pack.

[0013] Preferably, the control circuit includes an analog front-end unit and a control unit communicatively connected to the analog front-end unit. The input terminal of the analog front-end unit is connected to the battery pack and the current acquisition unit, the output terminal of the analog front-end unit is connected to the charge-discharge drive circuit, and the output terminal of the control unit is connected to the control terminal of the switch drive circuit.

[0014] Preferably, the output terminal of the control unit is also connected to the charging and discharging drive circuit, and the control unit is used to lock the charging and discharging drive circuit in a certain state.

[0015] Preferably, the switching circuit includes a first MOSFET and a second MOSFET connected in series, with the body diodes in the first MOSFET and the second MOSFET having opposite directions.

[0016] Preferably, the switch driving circuit includes a first switch and a second switch connected in series. The second switch is connected between the first driving power supply and the gates of the first MOSFET and the second MOSFET. The control electrode of the first switch is connected to the control circuit. The first switch is used to control the on / off state of the second switch according to the output of the control circuit.

[0017] Preferably, a first pull-down circuit is provided between the gate and source of the first MOSFET, and a second pull-down circuit is provided between the gate and source of the second MOSFET; when the second MOSFET is in the off state, the first pull-down circuit is used to pull the voltage between the gate and source of the first MOSFET to a low level, and the second pull-down circuit is used to pull the voltage between the gate and source of the second MOSFET to a low level.

[0018] Preferably, a current-limiting resistor is also connected in series in the switching circuit.

[0019] Preferably, it also includes a temperature detection circuit for detecting the operating temperature of the current-limiting resistor, the output of the temperature detection circuit being connected to the control circuit, and the control circuit controlling the state of the switch drive circuit based on the detection value of the temperature detection circuit.

[0020] Preferably, the system further includes a voltage acquisition circuit connected to the control circuit. The voltage acquisition circuit is used to acquire the voltage between the negative terminal of the battery pack and the negative terminal of the power bus. The control circuit also controls the state of the switch drive circuit based on the voltage acquired by the voltage acquisition circuit.

[0021] Compared with existing technologies, the battery charging and discharging management circuit provided by the present invention, through the coordinated control of the charging switch, discharging switch, and parallel current limiting circuit by the regulating circuit, can dynamically switch the current limiting mode in the bidirectional charging and discharging path, meeting the high requirements for battery charging and discharging. Secondly, through the parallel design of the switching circuit and the charging / discharging switch, the current path of the power bus is directly used, eliminating the complex inductors, capacitors, and multi-stage switching devices in traditional solutions, significantly reducing the number of components and circuit size, and lowering hardware costs. In addition, since the current limiting circuit only needs to be turned on when current limiting is required, it is in a power-off state under normal operating conditions, with no redundant energy loss, resulting in high overall energy efficiency. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the battery charging and discharging management circuit in an embodiment of this utility model.

[0023] Figure 2 This is a circuit diagram of the current limiting circuit in an embodiment of this utility model.

[0024] Figure 3 This is a circuit diagram of the temperature detection circuit in an embodiment of this utility model.

[0025] Figure 4 This is a circuit diagram of the voltage detection circuit in an embodiment of the present invention. Detailed Implementation

[0026] To explain in detail the technical content, structural features, objectives and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0027] This embodiment discloses a battery charge and discharge management circuit that supports bidirectional current limiting during the charging and discharging processes of the battery pack BT, thereby meeting the high requirements for battery charging and discharging safety. It should be noted that the battery pack BT in this embodiment can consist of a single string of cells, or multiple sets of cells connected in series or parallel.

[0028] like Figure 1 The battery charge and discharge management circuit includes a power bus L, a charge and discharge drive circuit 2, a regulation circuit 1, and a current limiting circuit 4.

[0029] For the power bus L, one end's two pins B+ and B- are connected to the main electrode of the battery pack BT, and the other end's two pins C+ and C- are used to connect to the load. When used for charging, the load is the charger; when used for discharging, the load is an actuator that operates based on electrical energy.

[0030] A charging switch 5, a discharging switch 6, and a current collector 3 are also connected in series on the power bus L. The charging switch 5 and the discharging switch 6 are used to control the battery pack BT to enter the charging or discharging state. The current collector 3 is used to collect the charging or discharging current on the power bus L. This current collector 3 can be a resistor, current transformer, or other electrical device that can collect the current on the power bus L.

[0031] The input terminal of the charge / discharge drive circuit 2 is connected to the control circuit 1, and the output terminal is connected to the charging switch 5 and the discharging switch 6. This charge / discharge drive circuit 2 is used to control the state of the charging switch 5 and the discharging switch 6.

[0032] For the control circuit 1, one end is connected to the current acquisition device 3 to acquire the current information acquired by the current acquisition device 3. The control circuit 1 is used to control the state of the charging switch 5 and the discharging switch 6 by means of the charging and discharging drive circuit 2 based on the acquired information.

[0033] like Figure 2 The current limiting circuit 4 includes a switching circuit 40 and a switching drive circuit 41. The switching circuit 40 is connected in parallel with the charging switch 5 and the discharging switch 6.

[0034] The control terminal of the switching circuit 40 is connected to the switch driving circuit 41, which is used to control the current state on the switching circuit 40. The control terminal of the switch driving circuit 41 is connected to the regulation circuit 1.

[0035] The control circuit 1 also controls the state of the switch drive circuit 41 based on the collected information, so as to regulate the charging current or discharging current flowing through the switch circuit 40.

[0036] When it is necessary to regulate the charging current or discharging current, disconnect the charging switch 5 or the discharging switch 6 and connect the switching circuit 40. The working state of the switching circuit 40 is driven by the switching drive circuit 41, thereby achieving the purpose of adjusting the charging current or discharging current according to the needs.

[0037] On the other hand, the control circuit 1 includes an analog front-end unit (AFE) (also called an AFE integrated circuit) and a control unit MCU that is communicatively connected to the analog front-end unit AFE. The input terminal of the analog front-end unit AFE is connected to the current collector 3, the output terminal of the analog front-end unit AFE is connected to the charge and discharge drive circuit 2, and the output terminal of the control unit MCU is connected to the control terminal of the switch drive circuit 41.

[0038] On the other hand, the control circuit 1 is also connected to the battery pack BT, that is, the analog front-end unit AFE is connected to the battery pack BT to collect the state information of the battery pack BT, so that the control circuit 1 can control the state of the charging switch 5 and the discharging switch 6 according to the state of the battery pack BT. In this embodiment, the state information of the battery pack BT includes information such as the voltage and temperature of individual cells.

[0039] The following example, using charging current limiting, illustrates the working principle of the battery charging and discharging management circuit described above:

[0040] 1. During normal charging, if the charging current is not greater than the protection threshold (e.g., 100A), the control unit MCU controls the charging switch 5 to be in the closed state, and the charging current flows through the current collector 3 and the charging switch 5. At this time, the switch drive circuit 41 controls the switch circuit 40 to be in the open state.

[0041] 2. When the analog front-end unit (AFE) detects that the charging current is greater than the protection threshold or the battery pack BT is abnormal (such as abnormal cell voltage or temperature), it transmits the information to the control unit (MCU) via the I2C bus. Then, the control unit (MCU) instructs the analog front-end unit (AFE) to send a low-level control signal ACHG to the charge / discharge drive circuit 2.

[0042] 3. After receiving a low level ACHG, the charge / discharge drive circuit 2 outputs a control signal CHG to the charging switch 5 to control the charging switch 5 to open.

[0043] 4. Then, the control unit MCU outputs a PWM signal to the switch drive circuit 41 to start the switch circuit 40 and enter the charging current limiting working mode. The duty cycle of the PWM signal starts from 0% and gradually increases at a certain rate (such as 0.1%).

[0044] 5. In the charging current limiting mode, the control unit MCU continuously obtains the charging current through the analog front-end unit AFE. When the charging current exceeds the preset current limiting threshold (e.g., 10A) and the difference between the current limiting threshold and the current limiting threshold is greater than the preset value, the duty cycle of the PWM signal is gradually adjusted to reduce the charging current; conversely, the duty cycle of the PWM signal is gradually increased until the charging current is near the current limiting threshold.

[0045] 6. When the current-limited charging lasts for a certain period of time (e.g., 60 seconds), or when the voltage difference between the negative terminal C- of the load end of the power bus L and the negative terminal B- of the battery pack BT end is less than a preset threshold, the duty cycle of the control PWM signal is set to 0%, and the current-limited charging is stopped.

[0046] 7. The control unit MCU instructs the analog front-end unit AFE to send a high-level control signal ACHG to the charge / discharge drive circuit 2.

[0047] 8. After receiving the high-level control signal ACHG, the charging and discharging drive circuit 2 sends a control signal CHG to the charging switch 5 to turn on the charging switch 5 and enter the normal charging state.

[0048] 9. Continue to monitor the charging current. If overcurrent occurs, re-enter the charging current limiting mode.

[0049] The above details the working process of the battery charge and discharge management circuit disclosed in this embodiment for charging current limiting. The process for discharging current limiting is similar to that described above, and will not be repeated here.

[0050] On the other hand, the output of the control unit MCU is also connected to the charge / discharge drive circuit 2, and the control unit MCU is used to lock the charge / discharge drive circuit 2 in a certain state.

[0051] For example, when a charging abnormality is detected and current-limited charging is required, the control unit MCU instructs the analog front-end unit AFE to send a low-level control signal ACHG to the switch drive circuit 41. The control unit MCU will also send a low-level control signal MCHG to the switch drive circuit 41 to latch the charging switch 5 into the open state. This achieves dual redundancy of hardware protection and software control.

[0052] Specifically, the analog front-end unit (AFE) is a hardware unit that directly collects battery and current parameters. Its low-level ACHG output is a hardware-level protection action. For example, when an overcurrent is detected, the analog front-end unit (AFE) will directly and quickly shut off the charging switch 5 through internal logic. The response time is usually in the microsecond range, which is a primary protection mechanism.

[0053] The low level MCHG output by the control unit MCU is a latch signal at the software control level, belonging to the secondary protection mechanism. Its function is to persist the off state of charging switch 5 through a latch or flip-flop (such as a D-type flip-flop). Even if the ACHG signal of AFE fails due to interference or temporary recovery, MCHG can still maintain the off state to avoid false triggering.

[0054] On the other hand, such as Figure 2 The switching circuit 40 includes a first MOSFET M1 and a second MOSFET M2 connected in series, with the body diodes in the first MOSFET M1 and the second MOSFET M2 having opposite directions.

[0055] In this embodiment, the switch driving circuit 41 controls the switching frequency of the first MOSFET M1 and the second MOSFET M2 under the action of the PWM signal issued by the control unit MCU, so as to adjust the current flowing through the first MOSFET M1 and the second MOSFET M2.

[0056] Furthermore, when the first MOSFET M1 and the second MOSFET M2 are turned off, their body diodes are in reverse series connection. At this time, voltage in either direction will be blocked by the reverse-biased body diode, preventing the formation of a current path (for example, when one body diode is forward-biased, the other will necessarily be reverse-biased and cut off). This design completely solves the leakage current problem caused by the body diode being on when a single MOSFET is turned off.

[0057] In addition, if the power supply polarity is reversed or the load voltage is higher than the power supply voltage (such as the back electromotive force of a motor), the reverse-connected body diode can immediately block the reverse current and protect the downstream circuit from damage.

[0058] On the other hand, the switch driving circuit 41 includes a first switch Q1 and a second switch Q2 connected in series. The second switch Q2 is connected between the driving power supply VC1 (which can be drawn from the battery pack BT) and the gates of the first MOSFET M1 and the second MOSFET M2. The control electrode of the first switch Q1 is connected to the control circuit 1. The first switch Q1 is used to control the on / off state of the second switch Q2 according to the output of the control circuit 1.

[0059] In this embodiment, the control unit MCU outputs a PWM signal to control the first switch Q1 to alternately turn on and off. When the first switch Q1 is on, the second switch Q2 is on, thereby applying the drive power supply VC1 to the gates of the first MOSFET M1 and the second MOSFET M2, turning on the first MOSFET M1 and the second MOSFET M2. Conversely, when the first switch Q1 is off, the second switch Q2 is off, thereby making the gates of the first MOSFET M1 and the second MOSFET M2 low, turning on the first MOSFET M1 and the second MOSFET M2.

[0060] On the other hand, a first pull-down circuit is provided between the gate and source of the first MOSFET M1, and a second pull-down circuit is provided between the gate and source of the second MOSFET M2. When the second switch Q2 is in the off state, the first pull-down circuit is used to quickly pull the voltage between the gate and source of the first MOSFET M1 to a low level, and the second pull-down circuit is used to quickly pull the voltage between the gate and source of the second MOSFET M2 to a low level.

[0061] In this embodiment, by setting the first pull-down circuit and the second pull-down circuit, when the first MOSFET M1 and the second MOSFET M2 are turned off, the gate charge can be discharged quickly, which can reduce the transition time (i.e., the falling edge time) of the MOSFET from turn-on to turn-off, thereby reducing switching losses (especially in high-frequency applications), and avoiding device overheating or damage caused by turn-off delay.

[0062] Specifically, the first pull-down circuit includes a third switch Q3 and a first unidirectional diode D1. The two conducting terminals of the third switch Q3 are connected to the gate and source of the first MOSFET M1, respectively. The first unidirectional diode D1 is connected in series between the gate of the first MOSFET M1 and the second switch Q2. The control terminal and one of the conducting terminals of the third switch Q3 are connected to the two ends of the first unidirectional diode D1, respectively. A first resistor R1 is also provided between the control terminal and the other conducting terminal of the third switch Q3.

[0063] The second pull-down circuit includes a fourth switch Q4 and a second unidirectional diode D2. The two conducting terminals of the fourth switch Q4 are connected to the gate and source of the second MOSFET M2, respectively. The second unidirectional diode D2 is connected in series between the gate of the second MOSFET M2 and the second switch Q2. The control terminal and one of the conducting terminals of the fourth switch Q4 are connected to the two ends of the second unidirectional diode D2, respectively. A second resistor R2 is also provided between the control terminal and the other conducting terminal of the fourth switch Q4.

[0064] In the above embodiment, the first switch Q1 is an NPN transistor, and the second switch Q2, the third switch Q3 and the fourth switch Q4 are PNP transistors.

[0065] The working principle of the above-mentioned switch drive circuit 41 is as follows:

[0066] The second switch Q2 turns on when the first switch Q1 turns on, and turns off when the first switch Q1 turns off. The third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are voltage divider bias resistors.

[0067] When the second switch Q2 is turned on, the drive power supply VC1 drives the first MOSFET M1 to turn on through the seventh resistor R7, the third unidirectional diode D3, and the first unidirectional diode D1. At this time, the third switch Q3 is in the off state. When the first MOSFET M1 is turned on, the second MOSFET M2 is pulled low to the low level of the negative terminal B- of the battery pack BT through the body diode. Thus, the drive power supply VC1 drives the second MOSFET M2 to turn on completely through the seventh resistor R7, the fourth unidirectional diode D4, and the second unidirectional diode D2. At this time, the fourth switch Q4 is in the off state.

[0068] When the second switch Q2 is turned off, the drive power supply VC1 is cut off. Initially, the gate potential of the first MOSFET M1 (which is also the emitter potential of the third switch Q3) is greater than the anode potential of the first unidirectional diode D1 (which is also the base potential of the third switch Q3). At this time, the third switch Q3 is in the on state, thereby quickly pulling down the gate-source voltage of the first MOSFET M1 to a low level and quickly turning off the first MOSFET M1.

[0069] At this time, the first resistor R1 maintains the gate-source voltage of the first MOSFET M1 at a low level to prevent external interference or leakage current from causing the gate voltage to rise unexpectedly (avoiding the first MOSFET M1 from being turned on by mistake).

[0070] Similarly, in the initial state, the gate G potential of the second MOSFET M2 (that is, the emitter potential of the fourth switch Q4) is greater than the anode potential of the second unidirectional diode D2 (that is, the base potential of the fourth switch Q4). At this time, the fourth switch Q4 is in the conducting state, thereby quickly pulling down the gate-source voltage of the second MOSFET M2 to a low level and quickly turning off the second MOSFET M2.

[0071] At this time, the second resistor R2 maintains the gate-source voltage of the second MOSFET M2 at a low level to prevent external interference or leakage current from causing the gate voltage to rise unexpectedly (avoiding the second MOSFET M2 from being turned on by mistake).

[0072] On the other hand, a current-limiting resistor R0 is also connected in series with the switching circuit 40. This current-limiting resistor R0 limits the maximum current when the first MOSFET M1 and the second MOSFET M2 are turned on.

[0073] On the other hand, a temperature detection circuit 7 is also configured to detect the operating temperature of the current-limiting resistor R0. The output of the temperature detection circuit 7 is connected to the control circuit 1, and the control circuit 1 also controls the state of the switch drive circuit 41 according to the detection value of the temperature detection circuit 7. Based on this, in the current-limiting operating mode, the switching frequency of the first switch Q1 and the second switch Q2 can be controlled according to the detection value of the temperature detection circuit 7 to avoid burning out the first switch Q1 and the second switch Q2 due to excessive current.

[0074] It should be noted that the control of the switching circuit 40 based on the temperature detection circuit 7 has a higher priority than the control of the switching circuit 40 based on the threshold current.

[0075] Specifically, such as Figure 3 The temperature detection circuit 7 includes an eighth resistor R8 and a thermistor NTC connected in series between the second drive power supply VC2 and ground or (or the negative terminal B- of the battery pack). A voltage detection point JC1 is set between the eighth resistor R8 and the thermistor NTC, and the voltage detection point JC1 is connected to the control unit MCU through a ninth resistor R9. In addition, a filter capacitor C1 is connected in parallel across the thermistor NTC.

[0076] The NTC is a negative temperature coefficient resistor, which has a corresponding resistance value under different temperature conditions. This resistance value forms a voltage divider with the eighth resistor R8. Therefore, the resistance value of the NTC can be calculated by collecting the voltage at the voltage detection point JC1. Then, the temperature of the corresponding NTC (that is, the temperature of the current limiting resistor R0) can be obtained by looking up a table.

[0077] On the other hand, such as Figure 4 The battery charging and discharging management circuit also includes a voltage acquisition circuit 8 connected to the control circuit 1. The voltage acquisition circuit 8 is used to acquire the voltage between the negative terminal B- of the battery pack BT and the negative terminal C- of the power bus L. The control circuit 1 also controls the state of the switch drive circuit 41 according to the voltage VX acquired by the voltage acquisition circuit 8.

[0078] Specifically, the voltage acquisition circuit 8 includes a tenth resistor R10 and an eleventh resistor R11 connected in series between the third drive power supply VC3 and the negative terminal B- of the battery pack BT. The connection point JC2 of the tenth resistor R10 and the eleventh resistor R11 is connected to the negative terminal C- of the power bus L through the twelfth resistor R12. The connection point JC2 of the tenth resistor R10 and the eleventh resistor R11 is connected to the control unit MCU.

[0079] In addition, a filter circuit is provided at the signal output terminal of the voltage acquisition circuit 8. This filter circuit includes a thirteenth resistor R13 located at the connection point JC2 and a filter capacitor C2 connected in parallel with the thirteenth resistor R13.

[0080] The working principle of the voltage acquisition circuit 8 is as follows:

[0081] Let B- be at zero potential, and let VC be the voltage across C-.

[0082] (When VC is greater than 0, it represents the discharge state; conversely, when VC is less than or equal to 0, it represents the charging state.)

[0083] According to Kirchhoff's Current Law (KCL), we have the following formula:

[0084] (VC3-VX) / R10=VX / R11+(VX-VC) / R12---Formula 1.

[0085] Simplifying Formula 1, we get Formula 2 as follows:

[0086] VC=[(2*R12+R11)×VX-R12×VC3] / R11---Formula 2.

[0087] In summary, this utility model discloses a battery charging and discharging management circuit. By coordinating the control circuit 1 to control the charging switch 5, the discharging switch 6, and the parallel current limiting circuit 4, the current limiting mode can be dynamically switched in the bidirectional charging and discharging path to meet the high requirements for battery charging and discharging.

[0088] Secondly, by using the parallel design of the switching circuit 40 and the charging / discharging switch 6, the current path of the power bus L can be directly used, eliminating the complex inductors, capacitors and multi-stage switching devices in the traditional solution, significantly reducing the number of components and the circuit size, and lowering the hardware cost.

[0089] In addition, since the current limiting circuit 4 only needs to be turned on when current limiting is required, it is in a power-off state under normal operating conditions, with no redundant energy loss and high overall energy efficiency.

[0090] Furthermore, it can also control the magnitude of charging or discharging current based on the temperature, voltage, and other status information of the individual cells in the battery pack BT.

[0091] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the scope of the present utility model application shall still fall within the scope of the present utility model.

Claims

1. A battery charge / discharge management circuit supporting bidirectional current limiting, characterized in that, The application relates to a battery pack charging and discharging system, which comprises the following parts: a power bus, one end of which is connected with a total electrode of a battery pack and the other end of which is used for being connected with a load; a charging switch, a discharging switch and a current collector which are connected in series on the power bus; a charging and discharging drive circuit, an output end of which is connected with the charging switch and the discharging switch; a regulation circuit, one end of which is connected with the current collector to collect current information collected by the current collector, and the other end of which is connected with an input end of the charging and discharging drive circuit, the regulation circuit being used for controlling states of the charging switch and the discharging switch by means of the charging and discharging drive circuit according to the collected information; a current limiting circuit, which comprises a switch circuit and a switch drive circuit, the switch circuit being connected in parallel with the charging switch and the discharging switch, a control end of the switch circuit being connected with the switch drive circuit, the switch drive circuit being used for controlling current states on the switch circuit, and a control end of the switch drive circuit being connected with the regulation circuit; the regulation circuit further controls states of the switch drive circuit based on the collected information to regulate charging current or discharging current flowing through the switch circuit.

2. The battery charge and discharge management circuit of claim 1, wherein, The regulation circuit is further connected with the battery pack to collect state information of the battery pack, so that the regulation circuit can control states of the charging switch and the discharging switch according to the state of the battery pack.

3. The battery charge and discharge management circuit of claim 1, wherein, The regulation circuit comprises an analog front end unit and a control unit which is communicatively connected with the analog front end unit, an input end of the analog front end unit being connected with the battery pack and the current collector, an output end of the analog front end unit being connected with the charging and discharging drive circuit, and an output end of the control unit being connected with a control end of the switch drive circuit.

4. The battery charge and discharge management circuit of claim 3, wherein, An output end of the control unit is further connected with the charging and discharging drive circuit, and the control unit is used for locking the charging and discharging drive circuit in a certain state.

5. The battery charge-discharge management circuit according to claim 1, wherein The switch circuit comprises a first MOS tube and a second MOS tube which are connected in series, and the body diodes in the first MOS tube and the second MOS tube are in opposite directions.

6. The battery charge and discharge management circuit of claim 5, wherein, The switch drive circuit comprises a first switch tube and a second switch tube which are connected in series, the second switch tube being connected between a first drive power supply and gates of the first MOS tube and the second MOS tube, a control pole of the first switch tube being connected with the regulation circuit, and the first switch tube being used for controlling on / off states of the second switch tube according to outputs of the regulation circuit.

7. The battery charge-discharge management circuit according to claim 6, wherein First pull-down circuits are arranged between gates and sources of the first MOS tube and second pull-down circuits are arranged between gates and sources of the second MOS tube; when the second switch tube is in an off state, the first pull-down circuits are used for pulling voltages between the gates and the sources of the first MOS tube to a low level state, and the second pull-down circuits are used for pulling voltages between the gates and the sources of the second MOS tube to a low level state.

8. The battery charge-discharge management circuit according to claim 1, wherein A current limiting resistor is further connected in series on the switch circuit.

9. The battery charge-discharge management circuit according to claim 8, wherein, The temperature detection circuit is connected with the regulating circuit, and the regulating circuit controls the state of the switch driving circuit according to the detection value of the temperature detection circuit.

10. The battery charge-discharge management circuit according to claim 1, wherein The voltage acquisition circuit is connected with the regulating circuit, and the voltage acquisition circuit is used for acquiring the voltage between the negative electrode end of the battery pack and the negative electrode end of the power bus, and the regulating circuit controls the state of the switch driving circuit according to the voltage acquired by the voltage acquisition circuit.

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