WO2023016574A1

WO2023016574A1 - Switching circuit, battery management system, battery pack, electrical device and control method

Info

Publication number: WO2023016574A1
Application number: PCT/CN2022/115257
Authority: WO
Inventors: 陈勇; 雷雨
Original assignee: 东莞新能安科技有限公司
Priority date: 2021-08-11
Filing date: 2022-08-26
Publication date: 2023-02-16
Also published as: CN113690966A

Abstract

The present application provides a switching circuit, comprising a first switching transistor, a control module, and a discharge module. The first switching transistor is provided on in main circuit loop and electrically connected to the control module and the discharge module, respectively. The control module comprises a first pin, and the control module outputs a voltage signal by means of the first pin to instruct the first switching transistor to be turned on or off. The present application further provides a battery management system, a battery pack, an electric device, and a switching circuit control method.

Description

Switching circuit, battery management system, battery pack, electrical equipment and control method

This application claims the priority of the Chinese patent application submitted to the China Patent Office on August 11, 2021, with the application number CN202110922004.5, and the application name "Switching circuit, battery management system, battery pack, electrical equipment and control method" , the entire contents of which are incorporated in this application by reference.

technical field

The present application relates to the technical field of batteries, and in particular to a switch circuit, a battery management system, a battery pack, electrical equipment, and a switch circuit control method.

Background technique

The battery management system (Battery Management System, BMS) is a system that manages the charging and discharging of batteries. In the battery management system, the drive circuit controls the switching tube such as the MOS tube as the battery positive switch to output the battery voltage. When the switching tube is turned off, it needs to be turned off as soon as possible to avoid the switching tube working in an over-power state for a long time , resulting in damage to the switch tube. In the related art, it is difficult to quickly turn off the switch tube when the drive circuit is used to turn off the switch tube.

Contents of the invention

The present application provides a switch circuit, a battery management system, a battery pack, electrical equipment and a control method for the switch circuit, so as to improve the turn-off speed of the switch tube.

One aspect of the present application provides a switch circuit, including a first switch tube, a control module and a discharge module. The first switch tube is arranged in the main circuit loop and electrically connected with the control module and the discharge module respectively. The control module includes a first pin, and the control module is configured to output a voltage signal through the first pin, and the voltage signal is used to instruct the first switch tube to be turned on or off. Wherein, the voltage signal includes a first voltage signal, and the first voltage signal is used to indicate that the first switch tube is turned off. When the first pin outputs the first voltage signal, the first The switch tube is discharged through the discharge module.

In the above embodiment, by setting the discharge module, when the first switch tube is turned off, the discharge module discharges the first switch tube, so that the charge stored in the first switch tube can be quickly charged. and discharge to increase the turn-off speed of the first switch tube.

In some embodiments of the present application, the discharge module includes a primary discharge circuit. Two ends of the primary discharge circuit are respectively electrically connected to the first end of the first switching transistor and the second end of the first switching transistor. The first terminal of the first switching tube is also electrically connected to the first pin for receiving the voltage signal, and the third terminal of the first switching tube is used for electrically connecting with the first terminal of the battery. Wherein, the primary discharge circuit includes a second switch tube, the second switch tube is electrically connected to the first pin for receiving the voltage signal, and when the second switch tube is turned on, the The first switching tube is discharged through the primary discharge circuit.

In the above embodiment, the primary discharge circuit is used to accelerate the discharge of charges between the first terminal and the second terminal of the first switch transistor. In the process of turning off the first switching tube, the first switching tube is discharged through the primary discharge circuit, so that the turning off speed of the first switching tube can be increased.

In some embodiments of the present application, the primary discharge circuit further includes a first resistor and a second resistor, and the first resistor, the second resistor, and the second switch tube are connected in series with the first switch tube between the first end of the first switch tube and the second end of the first switching tube.

In the above embodiment, the first resistor is used to reduce the speed of driving the first switching tube to turn on and off, so as to avoid oscillation. The second resistor is the discharge resistor of the first switch tube, and is used to discharge the charge between the first terminal of the first switch tube and the second terminal of the second switch tube, so as to increase the Describe the turn-off speed of the first switch tube.

In some embodiments of the present application, the discharge module further includes a secondary discharge circuit, and the two ends of the secondary discharge circuit are respectively connected to the first end of the first switch tube and the second terminal of the first switch tube. electrical connection. Wherein, the secondary discharge circuit includes a third switch tube, the first end of the third switch tube is electrically connected to the third end of the first switch tube, and the second end of the third switch tube is connected to the The second terminal of the first switch tube is electrically connected, and when the third switch tube is turned on, the first switch tube is also discharged through the secondary discharge circuit.

In the above embodiment, the secondary discharge circuit is used to discharge the first switch tube to accelerate the charge between the first end of the first switch tube and the second end of the first switch tube. vent. During the process of turning off the first switching tube, discharging the first switching tube through the secondary discharge circuit can further increase the turning-off speed of the first switching tube.

In some embodiments of the present application, the secondary discharge circuit further includes a first resistor and a third resistor, and the first resistor, the third resistor and the third switch tube are connected in series with the first switch tube between the first end of the first switch tube and the second end of the first switching tube.

In the above embodiment, the third resistor is the bleeder resistor of the first switch tube, and is used to bleed the voltage between the first end of the first switch tube and the second end of the second switch tube. charge, so as to further increase the turn-off speed of the first switch tube.

In some embodiments of the present application, a fourth switch tube and a fourth resistor are further included, the fourth switch tube and the fourth resistor are connected in series with the third end of the first switch tube and the third switch tube between the first ends of the .

In the above embodiment, the fourth resistor is used to provide the driving current for the first terminal of the third switch tube.

In some embodiments of the present application, a charging module is further included, and the charging module includes a fifth resistor and capacitor unit. Wherein, the fifth resistor and the capacitor unit are connected in series between the first end of the fourth switch transistor and the second end of the third switch transistor.

In the above embodiment, the fifth resistor is used to provide the driving current for the first end of the fourth switch transistor. The capacitor unit is used to provide driving current for the fourth switch tube.

In some embodiments of the present application, a first diode is further included, the anode of the first diode is electrically connected to the first end of the fourth switch tube, and the cathode of the first diode is respectively connected to The third end of the first switch transistor is electrically connected to the second end of the fourth switch transistor.

In the above embodiment, the first diode is used to provide a discharge circuit for the capacitor unit, and at the same time ensure that the fourth switch tube will not be reversely broken down when the capacitor unit is discharging.

In some embodiments of the present application, the discharge module further includes a three-stage discharge circuit. The three-stage discharge circuit includes a first resistor and a sixth resistor. Wherein, the first resistor and the sixth resistor are connected in series between the first end of the first switch tube and the second end of the first switch tube, and the first switch tube passes through the three stages The discharge circuit discharges.

In the above embodiment, the first switch tube may be discharged through a three-stage discharge circuit, so as to further increase the turn-off speed of the first switch tube. The sixth resistor is the discharge resistor of the first switch tube. When the first pin outputs a first voltage signal indicating to turn off the first switch tube, the first terminal of the first switch tube can be connected to The voltage between the second end of the first switch tube and the second terminal is fixed at a low level, so that the level is more stable, and circuit instability caused by voltage suspension can be avoided.

In some embodiments of the present application, a second diode is also included, the anode of the second diode is electrically connected to the first pin, and the cathode of the second diode is connected to the first switch. The first ends of the tubes are electrically connected.

In the above embodiment, the second diode is an anti-reverse diode, which has an anti-reverse function, and can prevent the high-voltage pulse of the battery external device from directly impacting the first pin when it comes in, so that the first pin can have Sufficient high voltage pulse protection capability.

In some embodiments of the present application, a seventh resistor and an eighth resistor are also included, the first end of the seventh resistor is electrically connected to the first pin, and the second end of the seventh resistor is respectively connected to the The anode of the second diode, the first end of the second switch tube and the first end of the eighth resistor are electrically connected, and the second end of the eighth resistor is connected to the second end of the first switch tube. electrical connection.

In the above embodiment, the seventh resistor and the eighth resistor are used as the discharge resistor of the second switch tube, and the seventh resistor can also be used as a current limiting resistor to limit the current of the branch. , so as to prevent the first pin from outputting an instantaneous current that is too large, causing the first pin to output an exceeding rated current. The eighth resistor can also be used as a pull-down resistor at the first end of the second switch tube to prevent false conduction of the second switch tube.

One aspect of the present application provides a battery management system, which includes: a controller, and the switch circuit provided in the present application. Wherein, the controller is electrically connected to the control module, and the control module acquires a first signal of the controller, and the first signal is configured to instruct the control module to output a first voltage signal.

One aspect of the present application provides a battery pack, which includes: a cell module, and the battery management system provided in the present application. Wherein, the battery module includes at least one battery, the battery module is electrically connected to the battery management system, and the battery module is used to supply power to the battery management system.

One aspect of the present application provides an electric device, the electric device includes: a load, and the battery pack provided in the present application, the battery pack is electrically connected to the load, and the battery pack is used for The load is powered.

One aspect of the present application provides a switch circuit control method, the control method is used to control the switch circuit provided in the present application, the control method includes: when the first pin outputs a first voltage signal, The second switch tube is controlled to be turned on, and the charges between the first end of the first switch tube and the second end of the first switch tube are discharged through the primary discharge circuit.

In some embodiments of the present application, when the voltage between the third terminal of the first switching tube and the second terminal of the first switching tube is greater than or equal to the first threshold voltage, the third switching tube is controlled to and the fourth switch tube are turned on, and the charge between the first end of the first switch tube and the second end of the first switch tube is also discharged through the secondary discharge circuit.

In some embodiments of the present application, when the third switch tube is turned on, the charging module is in the charging state, and when the first terminal of the first switch tube is connected to the second terminal of the first switch tube After all the electric charges are released, the charging module stops charging.

In the above-mentioned switch circuit, battery management system, battery pack, electrical equipment and switch circuit control method of the present application, by setting a first switch tube, a control module and a discharge module, the control module includes a first pin, and the control module is configured to pass through the first pin. A pin outputs a voltage signal, and the voltage signal is used to indicate that the first switch tube is turned on or off; the voltage signal includes a first voltage signal, and the first voltage signal is used to indicate that the first switch tube is turned off, when the first pin When outputting the first voltage signal, the first switch tube discharges through the discharge module. When the first switch tube is turned off, the discharge module discharges the first switch tube to realize rapid discharge of the charge stored in the first switch tube, thereby increasing the turn-off speed of the first switch tube.

Description of drawings

FIG. 1 is a schematic structural diagram of a switch circuit provided by an embodiment of the present application;

FIG. 2 is a schematic diagram of the circuit structure of the switch circuit provided in the embodiment of the present application in the first scenario;

FIG. 3 is a schematic diagram of the circuit structure of the switch circuit provided in the embodiment of the present application in the second scenario;

FIG. 4 is a schematic diagram of the circuit structure of the switch circuit provided in the embodiment of the present application in the third scenario;

FIG. 5 is a schematic diagram of the circuit structure of the switch circuit provided in the embodiment of the present application in the fourth scenario;

FIG. 6 is a schematic structural diagram of a battery management system provided in an embodiment of the present application;

Fig. 7 is a schematic structural diagram of a battery pack provided by an embodiment of the present application;

Fig. 8 is a schematic structural diagram of an electrical device provided by an embodiment of the present application;

FIG. 9 is a schematic flowchart of a switching circuit control method provided in an embodiment of the present application;

FIG. 10 is another schematic flow chart of the switching circuit control method provided by the embodiment of the present application.

Detailed ways

The battery management system is a system that manages the charging and discharging of batteries. In the battery management system, the MCU can be used to control the on-off of switching tubes such as MOS tubes, so as to realize the connection and disconnection of the battery and external equipment (including electrical equipment and charging equipment) to manage the discharge or charge of the battery. When the switch tube is turned off, it needs to be turned off as soon as possible to avoid the switch tube working in an over-power state for a long time, resulting in damage to the switch tube.

In the related art, when using the drive circuit to turn off the switch tube, if the switch tube is to be turned off quickly, the performance requirements of the drive circuit are relatively high, and the cost will be increased accordingly. The purpose of quickly turning off the switching tube cannot be achieved. Therefore, it is difficult to quickly turn off the switching tube in the related art.

In order to improve the above-mentioned technical problems, the embodiment of the present application provides a switch circuit. When the switch tube is turned off, it is discharged through the discharge module to realize the rapid discharge of the charge in the switch tube, so as to improve the turn-off of the switch tube. speed. Therefore, the switching tube can be quickly turned off.

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the present application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application. In the case of no conflict, the following embodiments and technical features thereof can be combined with each other.

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of a switch circuit provided by an embodiment of the present application. In Fig. 1, the switch circuit includes a first switch tube Q1, a control module 101 and a discharge module 102, wherein the first switch tube Q1 is arranged in a main circuit loop, and the main circuit loop is composed of the positive terminal B+ of the battery, the P+ port, the load 103. The circuit formed by the P- port and the negative pole B- of the battery, that is, the main circuit circuit is: B+→P+ port→load 103→P- port→B-. It should be noted that, the P+ port and the P- port may be two ports for connecting the battery to an external device. In this embodiment of the present application, the load 103 may be an analog load, and in some embodiments, according to specific requirements, the load may also be a digital load.

In the embodiment of the present application, the first switching tube Q1 can be used as a positive switch of the battery to output the battery voltage, and the battery voltage can be controlled to supply power by turning on or off the first switching tube Q1. When the first switching tube Q1 is turned on, the battery voltage can be output to supply power to the electrical equipment (load 103 ). When the first switching tube Q1 is turned off, the battery voltage cannot be output, and no power is supplied at this time.

The first switch tube Q1 is electrically connected to the control module 101 and the discharge module 102 respectively. Wherein, the control module 101 may be an AFE, the control module 101 includes a first pin DSG, the control module 101 may be configured to output a voltage signal through the first pin DSG, and the voltage signal is used to indicate that the first switch tube Q1 is turned on or off. That is, outputting different voltage signals through the first pin DSG can instruct the first switching tube Q1 to be turned on or off. For example, outputting a voltage signal greater than or equal to the first threshold voltage through the first pin DSG can be regarded as outputting a high voltage signal to indicate that the first switch tube Q1 is turned on; outputting a voltage signal less than or equal to the first threshold voltage through the first pin DSG The voltage signal of the two threshold voltages can be regarded as an output low voltage signal for instructing the first switching tube Q1 to be turned off, wherein the second threshold voltage is smaller than the first threshold voltage. For example, a voltage signal of about 12V is output through the first pin DSG to close the first switch tube Q1 , and a voltage signal of about 0V is output through the first pin DSG to turn off the first switch tube Q1 .

It should be noted that the above voltage signal may include a first voltage signal, and the first voltage signal is used to instruct the first switching tube Q1 to be turned off. That is, when the first pin DSG outputs a first voltage signal, the first voltage signal may be a low voltage signal, such as a voltage signal around 0V, used to instruct the first switching tube Q1 to turn off. In addition, when the first pin DSG outputs the first voltage signal, it indicates that the first switching tube Q1 is turned off. When the first switching tube Q1 is switched from the on state to the off state, the first switching tube Q1 cannot immediately is completely turned off, at this moment, the first switching tube Q1 needs to discharge the charge stored in the parasitic capacitor, and the first switching tube Q1 is completely turned off after the charge is completely discharged. The turn-off time of the first switching tube Q1 should not be too long, otherwise the first switching tube Q1 will be damaged because the first switching tube Q1 is in an overpower state for a long time.

By setting the discharge module 102, when the first switch tube Q1 is about to be turned off, the first switch tube Q1 can be discharged through the discharge module 102, so as to accelerate the discharge of the charge stored in the parasitic capacitance of the first switch tube Q1. For example, when working normally, the first pin DSG outputs a high-voltage signal, the first switch tube Q1 is turned on, and is in the conduction state, and the main circuit loop works normally. When there is a need to turn off the first switch tube Q1, for example, the user When the first switching tube Q1 is normally turned off, or when an overcurrent, high current or high voltage protection occurs, the first switching tube Q1 needs to be turned off to avoid burning out the battery.

The first pin DSG of the control module 101 outputs a low voltage signal. The low voltage signal comes from the controller in the battery management system. The controller sends a digital signal to the control module 101. After receiving the digital signal, the control module 101 passes the first The pin DSG outputs an analog low-voltage signal, such as a low-voltage signal around 0V, and the low-voltage signal is used to instruct the first switching tube Q1 to turn off. During the process of turning off the first switching tube Q1, the charge between the first terminal of the first switching tube Q1 and the second terminal of the first switching tube Q1 is discharged through the discharge module 102, and the first After the charge between the terminal and the second terminal of the first switching transistor Q1 is completely discharged, the first switching transistor Q1 will be completely turned off. Therefore, the discharge through the discharge module 102 can increase the turn-off speed of the first switching tube Q1.

It can be understood that, in the embodiment of the present application, by setting the first switch tube Q1, the control module 101 and the discharge module 102, the control module 101 is configured to output a voltage signal through the first pin DSG, and the voltage signal is used to indicate the first The switch tube Q1 is turned on or off. The voltage signal includes a first voltage signal, and the first voltage signal is used to indicate that the first switching tube Q1 is turned off. When the first pin DSG outputs the first voltage signal, the first switching tube Q1 can be discharged through the discharge module 102 . When the first switching tube Q1 is turned off, the discharge module 102 discharges the first switching tube Q1, so that the charge can be quickly discharged, and specifically, the connection between the first terminal and the second terminal of the first switching tube Q1 is realized. The rapid discharge of the charge between them can increase the turn-off speed of the first switching tube Q1.

Please refer to FIG. 2 . FIG. 2 is a schematic diagram of a circuit structure of a switch circuit provided in an embodiment of the present application in a first scenario. In FIG. 2 , the discharge module 102 includes a primary discharge circuit 201, the two ends of the primary discharge circuit 201 are respectively electrically connected to the first end of the first switching tube Q1 and the second end of the first switching tube Q1, and the first switch The first terminal of the tube Q1 is also electrically connected to the first pin DSG for receiving a voltage signal, and the third terminal of the first switching tube Q1 is used for electrically connecting with the first terminal of the battery. For example, the first terminal of the battery can be is the positive pole B+ of the battery, the second terminal of the battery can be the negative pole B- of the battery, and the third terminal of the first switching tube Q1 can be used to connect with the positive pole B+ of the battery, so as to output the battery voltage as the positive pole switch of the battery.

Optionally, the first switching transistor Q1 may be a MOS transistor, the first end of the first switching transistor Q1 may be the gate of the MOS transistor, and the second end of the first switching transistor Q1 may be the source of the MOS transistor, The third terminal of the first switching transistor Q1 may be the drain of the MOS transistor. In some embodiments, the first switch tube may also be other types of dedicated electronic switch tubes, such as triodes, or other types of power switch tubes.

Among them, the primary discharge circuit 201 is used to speed up the discharge of charge between the first terminal and the second terminal of the first switching tube Q1. When the first switching tube Q1 is a MOS tube, the primary discharge circuit 201 can speed up the discharge of the MOS tube The discharge of charge between the gate and source.

The primary discharge circuit 201 includes a second switch tube Q2, the second switch tube Q2 is electrically connected to the first pin DSG, and is used to receive the voltage signal output by the first pin DSG, when the second switch tube Q2 is turned on, The first switching transistor Q1 can discharge through the primary discharge circuit 201 , that is, the charge between the first terminal of the first switching transistor Q1 and the second terminal of the first switching transistor Q1 is discharged through the primary discharging circuit 201 . In the process of turning off the first switching tube Q1 , the first switching tube Q1 is discharged through the primary discharge circuit 201 , so that the turning off speed of the first switching tube Q1 can be increased.

Optionally, the primary discharge circuit 102 may further include a first resistor R1 and a second resistor R2, wherein the first resistor R1, the second resistor R2 and the second switch Q2 are connected in series with the first end of the first switch Q1 and between the second terminal of the first switch tube Q1. Specifically, the first end of the first resistor R1 is electrically connected to the first end of the first switching tube Q1, the second end of the first resistor R1 is electrically connected to the second end of the second switching tube Q2, and the second switching tube Q2 The third terminal of the second resistor R2 is electrically connected to the first terminal of the second resistor R2, the first terminal of the second switch tube Q2 is electrically connected to the first pin DSG, and the second terminal of the second resistor R2 is connected to the first terminal of the first switch tube Q1 The two terminals are electrically connected.

Optionally, the second switch tube Q2 may be a MOS tube, the first end of the second switch tube Q2 may be the gate of the MOS tube, and the second end of the second switch tube Q2 may be the source of the MOS tube , the third end of the second switching transistor Q2 may be the drain of the MOS transistor. In some embodiments, the second switch tube may also be other types of dedicated electronic switch tubes, such as triodes, or other types of power switch tubes.

It should be noted that, in the embodiment of the present application, the first resistor R1 is used to reduce the speed at which the first switching transistor Q1 is turned on and off, so as to avoid oscillation. The second resistor R2 is the discharge resistor of the first switching tube Q1, and is used to discharge the charge between the first terminal of the first switching tube Q1 and the second terminal of the second switching tube Q2, so as to boost the first switching tube Q1 shutdown speed.

For example, when the first pin DSG outputs a first voltage signal, such as a low voltage signal around 0V, the voltage at the first end of the second switching tube Q2 is a low voltage, such as 0V, because the first switching tube Q1 is turning off , it cannot be turned off instantaneously, and the voltage at the second end of the second switching tube Q2 will not change abruptly. At this time, the voltage at the second end of the second switching tube Q2 is a high voltage, such as 12V. There is a voltage difference with the second end of the second switching tube Q2, the second switching tube Q2 is turned on, and the charge between the first end of the first switching tube Q1 and the second end of the first switching tube Q1 passes through the first resistor R1, the second switch tube Q2 and the second resistor R2 are discharged to increase the turn-off speed of the first switch tube Q1.

Please refer to FIG. 3 . FIG. 3 is a schematic circuit structure diagram of the switch circuit provided in the embodiment of the present application in the second scenario. In FIG. 3 , the discharge module 102 may further include a secondary discharge circuit 202, the two ends of the secondary discharge circuit 202 are respectively electrically connected to the first end of the first switching transistor Q1 and the second end of the first switching transistor Q1, The secondary discharge circuit 202 is used to discharge the first switching transistor Q1 to speed up the discharge of charges between the first end of the first switching transistor Q1 and the second end of the first switching transistor Q1 .

Wherein, the secondary discharge circuit 202 may include a third switching tube Q3, the first end of the third switching tube Q3 is electrically connected to the third end of the first switching tube Q1, and the second end of the third switching tube Q3 is connected to the third switching tube Q3. The second end of a switch tube Q1 is electrically connected. When the third switching tube Q3 is turned on, the first switching tube Q1 can be discharged through the secondary discharge circuit 202, that is, the charge between the first end of the first switching tube Q1 and the second end of the first switching tube Q1 passes through the two The stage discharge circuit 202 is discharged. In the process of turning off the first switching tube Q1, the first switching tube Q1 is discharged through the secondary discharge circuit 202, which can further increase the turning-off speed of the first switching tube Q1.

Optionally, the secondary discharge circuit 202 may further include a first resistor R1 and a third resistor R3, and the first resistor R1, the third resistor R3 and the third switching transistor Q3 are connected in series with the first end of the first switching transistor Q1 and the third switching transistor Q1. Between the second terminals of a switch tube Q2. Specifically, the first end of the first resistor R1 is electrically connected to the first end of the first switch tube Q1, the second end of the first resistor R1 is electrically connected to the first end of the third resistor R3, and the second end of the third resistor R3 The two terminals are electrically connected to the third terminal of the third switching transistor Q3.

Optionally, the third switching transistor Q3 may be a triode, the first end of the third switching transistor Q3 may be the base of the triode, the second end of the third switching transistor Q3 may be the emitter of the triode, and the third The third terminal of the switch transistor Q3 may be the collector of the triode. In some embodiments, the third switch tube may also be other types of dedicated electronic switch tubes, such as other types of triodes, or other types of power switch tubes.

It should be noted that, in the embodiment of the present application, the third resistor R3 is the discharge resistor of the first switch tube Q1, and is used to discharge the connection between the first terminal of the first switch tube Q1 and the second terminal of the second switch tube Q2. The charge between them is used to increase the turn-off speed of the first switching tube Q1.

When the third switch tube Q3 is turned on, the charge between the first terminal of the first switch tube Q1 and the second terminal of the first switch tube Q1 is discharged through the first resistor R1, the third resistor R3 and the third switch tube Q3 , so as to further increase the turn-off speed of the first switching tube Q1.

Optionally, the switch circuit may further include a fourth switch tube Q4 and a fourth resistor R4, and the fourth switch tube Q4 and the fourth resistor R4 are connected in series with the third terminal of the first switch tube Q1 and the third end of the third switch tube Q3. between one end. Specifically, the first end of the fourth switching transistor Q4 is electrically connected to the second end of the third switching transistor Q3, the second end of the fourth switching transistor Q4 is electrically connected to the third end of the first switching transistor Q1, and the fourth switching The third end of the transistor Q4 is electrically connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is electrically connected to the first end of the third switching transistor Q3.

The fourth resistor R4 is used to provide the driving current for the first end of the third switch tube Q3. For example, when the third switching transistor Q3 is a triode, the fourth resistor R4 can be used as the base resistor of the third switching transistor Q3 to inject current into the base of the third switching transistor Q3, that is, the bias current.

When the fourth switch tube Q4 is turned on, the drive current passes through the fourth resistor R4 to the first end of the third switch tube Q3, and when the first end of the third switch tube Q3 and the second end of the third switch tube Q3 When the voltage reaches the turn-on voltage Vbe1 (generally 0.7V), the third switch Q3 is turned on, and the charge between the first end of the first switch Q1 and the second end of the first switch Q1 passes through the first resistor R1, the third resistor R3 and the third switching tube Q3 are further discharged to further increase the turn-off speed of the first switching tube Q1.

Optionally, the fourth switching transistor Q4 may be a triode, the first end of the fourth switching transistor Q4 may be the base of the triode, the second end of the fourth switching transistor Q4 may be the emitter of the triode, and the fourth The third terminal of the switch transistor Q4 may be the collector of the triode. In some embodiments, the fourth switch tube may also be other types of dedicated electronic switch tubes, such as other types of triodes, or other types of power switch tubes.

Please refer to FIG. 4 . FIG. 4 is a schematic diagram of a circuit structure of a switch circuit provided in an embodiment of the present application in a third scenario. In FIG. 4, the switch circuit may further include a charging module 104, and the charging module 104 may include a fifth resistor R5 and a capacitor unit 401, wherein the fifth resistor R5 and the capacitor unit 401 are connected in series to the first end of the fourth switch tube Q4 and between the second end of the third switching tube Q3.

It should be noted that the fifth resistor R5 is used to provide the driving current for the first end of the fourth switching transistor Q4. For example, when the fourth switching transistor Q4 is a triode, the fifth resistor R5 can be used as a base resistor of the fourth switching transistor Q4 to inject current into the base of the fourth switching transistor Q4, that is, a bias current.

Taking the first switching tube Q1 as a MOS tube, the third switching tube Q3 as a triode, and the fourth switching tube Q4 as a triode as an example, with the discharge of the first switching tube Q1, the first end of the first switching tube Q1 and the first The voltage Vgs between the second end of the switch tube Q1 gradually decreases, resulting in an increase in the impedance Rds between the third end of the first switch tube Q1 and the second end of the first switch tube Q1, and correspondingly, the The voltage Vds between the third terminal and the second terminal of the first switching transistor Q1 increases gradually. It should be noted that the Vgs of the MOS transistor is generally about 3V. When the Vgs gradually decreases, the impedance Rds will increase rapidly, generally from the mΩ level to the Ω level.

The fourth switching tube Q4 has a body diode, when the voltage Vds between the third terminal of the first switching tube Q1 and the second terminal of the first switching tube Q1 gradually increases to the turn-on voltage of the body diode of the fourth switching tube Q4 When Vbe2 (generally 0.7V), the first terminal of the fourth switching transistor Q4 conducts with the second terminal of the fourth switching transistor Q4, and the battery charges the capacitor unit 401 to form a driving current.

The driving current drives the fourth switching tube Q4 to turn on, and the driving current further flows to the first terminal of the third switching tube Q3 through the fourth resistor R4, when the first terminal of the third switching tube Q3 and the first terminal of the third switching tube Q3 When the voltage between the two terminals reaches the conduction voltage Vbe1 of the third switching tube Q3, the third switching tube Q3 is turned on, and at this time, the gap between the first terminal of the first switching tube Q1 and the second terminal of the first switching tube Q1 is The charge is further discharged or discharged through the first resistor R1, the third resistor R3 and the third switch tube Q3, further increasing the turn-off speed of the first switch tube Q1.

In addition, when the charge between the first terminal of the first switching tube Q1 and the second terminal of the first switching tube Q1 is discharged or discharged through the first resistor R1, the third resistor R3 and the third switching tube Q3, thereby The Vds of the first switching tube Q1 is increased (the on-resistance Ron is increased), so that the driving current of the third switching tube Q3 is increased, and the third switching tube Q3 is maintained in saturation until the Vds of the first switching tube Q1 is no longer If it is increased further, the voltage of Vds of the first switching tube Q1 drops to 0V, so as to ensure that the first switching tube Q1 is completely turned off and the safety of the circuit is ensured.

Optionally, the capacitor unit 401 may include a first capacitor C1 and a second capacitor C2, and the function of the first capacitor C1 and the second capacitor C2 is to provide a driving current to the fourth switch tube Q4 to turn on the fourth switch tube Q4, At the same time, when the first switching tube Q1 is completely turned off, the first capacitor C1 and the second capacitor C2 are fully charged, which is equivalent to disconnecting the fourth switching tube Q4, the fifth resistor R5, the first capacitor C1 and the second capacitor C2. The loop reduces power consumption and ensures that the P+ port has no leakage.

It can be understood that, when the second switching tube Q2 is turned on, as the Vgs of the first switching tube Q1 decreases, the Vds of the first switching tube Q1 gradually increases, and when the Vds of the first switching tube Q1 is greater than that of the fourth switching tube When the turn-on voltage of Q4 is Vbe2, the first capacitor C1 and the second capacitor C2 are charged through the fourth switch tube Q4 and the fifth resistor R5, the instantaneous emitter current of the fourth switch tube Q4 is large, and the fourth switch tube Q4 saturates and conducts On, the positive pole B+ total voltage of the battery directly drives the third switch tube Q3 to conduct, and the charge between the first end and the second end of the first switch tube Q1 passes through the first resistor R1, the third resistor R3 and the third switch tube Q3 quickly discharges, so as to quickly turn off the first switching tube Q1.

Optionally, the switching circuit may further include a first diode D1, the anode of the first diode D1 is electrically connected to the first end of the fourth switching transistor Q4, and the cathode of the first diode D1 is connected to the first end of the first diode D1 respectively. The third terminal of the switching transistor Q1 is electrically connected to the second terminal of the fourth switching transistor Q4. The function of the first diode D1 is to provide a discharge circuit for the first capacitor C1 and the second capacitor C2, and at the same time ensure that the fourth switching tube Q4 will not be reversely struck when the first capacitor C1 and the second capacitor C2 are discharging. wear.

Please refer to FIG. 5 . FIG. 5 is a schematic diagram of a circuit structure of a switch circuit provided in an embodiment of the present application in a fourth scenario. In FIG. 5 , the discharge module 102 may further include a three-stage discharge circuit 203 through which the first switching tube Q1 can discharge, that is, the first end of the first switching tube Q1 and the first end of the first switching tube Q1 The charge between the second terminals can be discharged through the three-level discharge circuit 203 .

The three-stage discharge circuit 203 may include a first resistor R1 and a sixth resistor R6, wherein the first resistor R1 and the sixth resistor R6 are connected in series with the first end of the first switch Q1 and the second end of the first switch Q2 between. Specifically, the first end of the first resistor R1 is electrically connected to the first end of the first switch tube Q1, the first end of the sixth resistor R6 is electrically connected to the second end of the first switch tube Q1, and the first end of the first resistor R1 The second end is electrically connected to the second end of the sixth resistor R6.

It should be noted that the sixth resistor R6 is the discharge resistor of the first switch tube Q1, specifically, it may be a pull-down resistor. When the first pin DSG outputs a first voltage signal indicating to turn off the first switch tube Q1, the first switch tube Q1 may be turned off. The voltage between the first terminal of the first switching tube Q1 and the second terminal of the first switching tube Q1 is fixed at a low level, making the voltage more stable and avoiding circuit instability caused by voltage suspension.

It can be understood that when the first switching tube Q1 is turned off, it can discharge through the first resistor R1 and the sixth resistor R6, that is, the connection between the first terminal of the first switching tube Q1 and the second terminal of the first switching tube Q1 The electric charge between can be discharged through the first resistor R1 and the sixth resistor R6, so as to further increase the turn-off speed of the first switching tube Q1.

Optionally, the switching circuit further includes a second diode D2, the anode of the second diode D2 is electrically connected to the first pin DSG, and the cathode of the second diode D2 is connected to the first pin of the first switching tube Q1. electrical connection. The second diode D2 is an anti-reverse diode, which has an anti-reverse function and can prevent the high-voltage pulse of P+ from directly impacting the first pin DSG, so that the first pin DSG has sufficient high-voltage pulse protection capability. The switch circuit not only has the function of quickly turning off the first switch tube Q1, but also has the function of high voltage pulse protection. Since there is no special requirement on the control module 101 itself, the embodiment of the present application can improve the safety and reliability of the switching circuit at low cost, and can ensure the safe and reliable operation of the battery management system and the safe and efficient operation of the battery system.

Optionally, the switch circuit may further include a seventh resistor R7 and an eighth resistor R8, the first end of the seventh resistor R7 is electrically connected to the first pin DSG, and the second end of the seventh resistor R7 is connected to the second pin DSG respectively. The anode of the pole transistor D2, the first end of the second switching transistor Q2 are electrically connected to the first end of the eighth resistor R8, and the second end of the eighth resistor R8 is electrically connected to the second end of the first switching transistor Q1.

Among them, the seventh resistor R7 and the eighth resistor R8 are used as the discharge resistor of the second switch tube Q2, and the seventh resistor R7 can also be used as a current limiting resistor to limit the current of the branch to prevent the first pin from The DSG output instantaneous current is too large, causing the first pin DSG output to exceed the rated current.

The first switching tube Q1 in the embodiment of the present application can be a power MOS tube of the positive terminal B+ of the battery (the total positive terminal of the battery). Generally, the parasitic capacitance Cgs≈7nF between the gate and the source of a single MOS tube, in order to increase the overcurrent capability And to reduce the temperature rise of the power MOS tube, usually multiple power MOS tubes are used in parallel. At this time, the capacitance of Cgs is relatively large. When the power MOS tube is turned on, the size of the seventh resistor R7 will affect the turn-on time of the power MOS tube, so The resistance values of the first resistor R1 and the seventh resistor R7 cannot be too large. For example, the sum of the resistance values of R1 and R7 can be limited to be less than or equal to the preset resistance threshold. If the preset resistance threshold is 1KΩ, then R1+R7≤1KΩ , etc., the resistance values of the first resistor R1 and the seventh resistor R7 can be adjusted according to specific application scenarios or specific requirements, and are not particularly limited in this embodiment of the present application.

Taking the second switching tube Q2 as an example of a MOS tube, when the first pin DSG outputs the first voltage signal, the first switching tube Q1 starts to turn off, and the voltage of the gate of the second switching tube Q2 passes through the seventh resistor R7 and the eighth resistor R8 for discharge, the voltage drop between the source and the gate of the second switching tube Q2 is greater than or equal to the threshold voltage Vgs(th) between the gate and the source when the second switching tube Q2 starts to conduct , the second switching tube Q2 is saturated and turned on, the voltage between the first terminal of the first switching tube Q1 and the second terminal of the first switching tube Q1 will drop rapidly, so as to further increase the turn-off speed of the first switching tube Q1 .

It should be noted that the eighth resistor R8 may be a resistor with a relatively large resistance, for example, a resistor of KΩ or MΩ level. The eighth resistor R8 can also be used as a pull-down resistor at the first end of the second switching tube Q2. When the first pin DSG outputs the first voltage signal that turns off the first switching tube Q1, the first terminal of the second switching tube Q2 is turned off. The potential of the terminal is pulled down to the potential of the P+ port to prevent the second switch tube Q2 from being misconducted.

Optionally, the switch circuit further includes a voltage regulator tube ZD1, which is a Vgs protection voltage regulator tube of the first switch tube Q1, and is used to prevent the Vgs of the first switch tube Q1 from exceeding the rated voltage, thereby damaging the first switch tube Q1. Switch tube Q1.

The embodiment of the present application also provides a battery management system, please refer to FIG. 6 , which is a schematic structural diagram of the battery management system provided in the embodiment of the present application. The battery management system 500 includes a controller 501 and a switch circuit 502 provided in the embodiment of the present application. The switch circuit 502 includes a control module 503, wherein the controller 501 is electrically connected to the control module 503, and the control module 503 obtains the first signal, the first signal is configured to instruct the control module 503 to output a first voltage signal, such as a low voltage signal, and the low voltage signal indicates that the first switch tube in the switch circuit 502 is turned off.

The embodiment of the present application also provides a battery pack, please refer to FIG. 7 , which is a schematic structural diagram of the battery pack provided in the embodiment of the present application. The battery pack 600 includes a cell module 601 and a battery management system 602 provided in the embodiment of the present application, wherein the cell module 601 includes at least one cell, that is, the cell module 601 may include one or more cells, The battery module 601 is electrically connected to the battery management system 602 , and the battery module 601 is used to supply power to the battery management system 602 to make the battery management system 602 work normally.

The embodiment of the present application also provides an electric device, please refer to FIG. 8 , which is a schematic structural diagram of the electric device provided by the embodiment of the present application. The electric device 700 includes a load 701 and a battery pack 702 provided by the embodiment of the present application. The battery pack 702 is electrically connected to the load 701 . The battery pack 702 is used to supply power to the load 701 to make the load 701 work normally.

On the basis of the switching circuits described in FIGS. 2 to 5 , the following uses FIGS. 9 and 10 as examples to describe the switching circuit control method of the embodiment of the present application. The switching circuit control method is used to control the switching circuit provided in the embodiment of the present application.

Please refer to FIG. 9 . FIG. 9 is a schematic flowchart of a switching circuit control method provided in an embodiment of the present application. The switching circuit control method may include:

S11. When the first pin outputs the first voltage signal, control the second switch to be turned on, and the charge between the first end of the first switch and the second end of the first switch is discharged through the primary discharge circuit.

When the first pin of the control module outputs the first voltage signal, such as when outputting a low voltage signal around 0V, the second switching tube is controlled to be turned on, and the first terminal of the first switching tube is connected to the second terminal of the first switching tube. The charge between terminals is discharged through a primary discharge circuit, such as through the second switch tube, so as to increase the turn-off speed of the first switch tube. It can be understood that, when the first switching tube is turned off, the first switching tube is discharged through the first-stage discharge circuit to realize rapid discharge of charges, thereby increasing the turn-off speed of the first switching tube. Therefore, the present application can quickly turn off the switching tube.

Please refer to FIG. 10 . FIG. 10 is another schematic flow chart of the switching circuit control method provided by the embodiment of the present application. The switching circuit control method may include:

S21. When the first pin outputs the first voltage signal, control the second switch tube to conduct, and the charge between the first end of the first switch tube and the second end of the first switch tube is discharged through the primary discharge circuit.

For a specific embodiment of S21, reference may be made to the embodiment of S11, which will not be repeated here.

S22. When the voltage between the third terminal of the first switching tube and the second terminal of the first switching tube is greater than or equal to the first threshold voltage, control the third switching tube and the fourth switching tube to conduct, and the first switching tube The charge between the first end of the first switch tube and the second end of the first switch tube is also discharged through the secondary discharge circuit.

When the voltage between the third end of the first switch tube and the second end of the first switch tube is greater than or equal to the first threshold voltage, the fourth switch tube is controlled to be turned on, thereby further controlling the third switch tube to be turned on, and the second switch tube is controlled to be turned on. The charge between the first end of the first switch tube and the second end of the first switch tube is also discharged through the secondary discharge circuit to further accelerate the discharge of the charge, thereby further increasing the turn-off speed of the first switch tube. It should be noted that the first threshold voltage may be the turn-on voltage of the fourth switch tube. When the fourth switch tube is a triode, the turn-on voltage of the fourth switch tube is the conduction voltage between the base and the emitter of the triode. The pass voltage is generally 0.7V.

S23. When the third switching transistor is turned on, the charging module is in a charging state, and when the charge between the first end of the first switching transistor and the second end of the first switching transistor is released, the charging module stops charging.

When the third switch tube is turned on, the charging module is in the charging state, and when the charge between the first end of the first switch tube and the second end of the first switch tube is released and the first switch tube is completely turned off, The charging module stops charging. By completely turning off the first switch tube, the safety of the circuit can be enhanced.

Although the application has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. This application includes all such modifications and variations and is limited only by the scope of the appended claims. With particular reference to the various functions performed by the components described above, terminology used to describe such components is intended to correspond to any component that performs the specified function (eg, which is functionally equivalent) of the described component (unless otherwise indicated). , even if not structurally equivalent to the disclosed structures that perform the functions shown herein in the exemplary implementations of the specification.

That is, the above descriptions are only embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process conversion made by using the specification and drawings of the present application, such as the technical features of the various embodiments The mutual combination, or direct or indirect application in other related technical fields, are all included in the scope of patent protection of this application.

In addition, in the description of the present application, it should be understood that the orientation or positional relationship indicated by the term "inside" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, rather than Nothing to indicate or imply that a referenced device or element must have a particular orientation, be constructed, and operate in a particular orientation should therefore not be construed as limiting the application. In addition, for structural elements with the same or similar characteristics, the present application may use the same or different symbols for identification. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "plurality" means two or more, unless otherwise specifically defined.

In this application, the word "exemplary" is used to mean "serving as an example, illustration or illustration". Any one embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The above description is given in order to enable anyone skilled in the art to implement and use the application. In the description above, various details are set forth for purposes of explanation. It should be understood that one of ordinary skill in the art would recognize that the present application may be practiced without these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of the present application with unnecessary detail. Thus, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in this application.

Claims

A switch circuit, including a first switch tube, a control module and a discharge module, wherein,

The first switching tube is arranged in the main circuit loop and is electrically connected to the control module and the discharge module respectively;

The control module includes a first pin, the control module is configured to output a voltage signal through the first pin, and the voltage signal is used to instruct the first switch tube to be turned on or off;

Wherein, the voltage signal includes a first voltage signal, and the first voltage signal is used to indicate that the first switch tube is turned off. When the first pin outputs the first voltage signal, the first The switch tube is discharged through the discharge module.
The switch circuit according to claim 1, wherein the discharge module comprises a primary discharge circuit, the two ends of the primary discharge circuit are respectively connected to the first end of the first switch tube and the first switch tube The second end of the first switch tube is electrically connected to the first pin, and is used to receive the voltage signal, and the third end of the first switch tube is used to connect with the battery The first end of the electrical connection;

Wherein, the primary discharge circuit includes a second switch tube, the second switch tube is electrically connected to the first pin for receiving the voltage signal, and when the second switch tube is turned on, the The first switching tube is discharged through the primary discharge circuit.
The switch circuit according to claim 2, wherein the primary discharge circuit further comprises a first resistor and a second resistor, and the first resistor, the second resistor and the second switch tube are connected in series to the Between the first end of the first switch tube and the second end of the first switch tube.
The switch circuit according to claim 2, wherein the discharge module further comprises a secondary discharge circuit, the two ends of the secondary discharge circuit are connected to the first end of the first switch tube and the first switch respectively. the second end of the tube is electrically connected;

Wherein, the secondary discharge circuit includes a third switch tube, the first end of the third switch tube is electrically connected to the third end of the first switch tube, and the second end of the third switch tube is connected to the The second terminal of the first switch tube is electrically connected, and when the third switch tube is turned on, the first switch tube is also discharged through the secondary discharge circuit.
The switch circuit according to claim 4, wherein the secondary discharge circuit further includes a first resistor and a third resistor, and the first resistor, the third resistor and the third switch tube are connected in series to the Between the first end of the first switch tube and the second end of the first switch tube.
The switch circuit according to claim 4, further comprising a fourth switch tube and a fourth resistor, the fourth switch tube and the fourth resistor are connected in series with the third terminal of the first switch tube and the between the first ends of the third switch tube.
The switch circuit according to claim 6, further comprising a charging module, the charging module comprising a fifth resistor and capacitor unit;

Wherein, the fifth resistor and the capacitor unit are connected in series between the first end of the fourth switch transistor and the second end of the third switch transistor.
The switch circuit according to claim 7, further comprising a first diode, the anode of the first diode is electrically connected to the first end of the fourth switch tube, and the first diode The cathode of the first switch tube is electrically connected to the third end of the first switch tube and the second end of the fourth switch tube respectively.
The switch circuit according to claim 2, wherein the discharge module further includes a three-stage discharge circuit, and the three-stage discharge circuit includes a first resistor and a sixth resistor;

Wherein, the first resistor and the sixth resistor are connected in series between the first end of the first switch tube and the second end of the first switch tube, and the first switch tube passes through the three stages The discharge circuit discharges.
The switch circuit according to any one of claims 2 to 9, further comprising a second diode, the anode of the second diode is electrically connected to the first pin, and the second two The cathode of the pole tube is electrically connected to the first end of the first switch tube.
The switch circuit according to claim 10, further comprising a seventh resistor and an eighth resistor, the first end of the seventh resistor is electrically connected to the first pin, and the second end of the seventh resistor respectively electrically connected to the anode of the second diode, the first end of the second switch tube, and the first end of the eighth resistor; the second end of the eighth resistor is connected to the first end of the first switch The second end of the tube is electrically connected.
A battery management system, wherein the battery management system comprises: a controller, and the switch circuit according to any one of claims 1 to 11;

Wherein, the controller is electrically connected to the control module, and the control module acquires a first signal of the controller, and the first signal is configured to instruct the control module to output a first voltage signal.
A battery pack, wherein the battery pack comprises: a cell module, and the battery management system according to claim 12;

Wherein, the battery module includes at least one battery, the battery module is electrically connected to the battery management system, and the battery module is used to supply power to the battery management system.
An electric device, wherein the electric device comprises: a load, and a battery pack according to claim 13, the battery pack is electrically connected to the load, and the battery pack is used to supply power to the load .
A switch circuit control method, wherein the control method is used to control the switch circuit according to any one of claims 7 to 11, the control method comprising:

When the first pin outputs the first voltage signal, the second switch tube is controlled to be turned on, and the charge between the first end of the first switch tube and the second end of the first switch tube passes through the The primary discharge circuit discharges.
The switching circuit control method according to claim 15, wherein when the voltage between the third terminal of the first switching transistor and the second terminal of the first switching transistor is greater than or equal to the first threshold voltage, the control The third switch tube and the fourth switch tube are turned on, and the charge between the first end of the first switch tube and the second end of the first switch tube is also discharged through the secondary discharge circuit .
The switching circuit control method according to claim 16, wherein, when the third switch tube is turned on, the charging module is in a charging state, and when the first end of the first switch tube is connected to the first After the charge between the second terminals of the switch tube is released, the charging module stops charging.