Switch driving circuit, battery management system, battery pack and electric equipment

Abstract

A switch driving circuit comprises a first switch, and the switch driving circuit comprises a control circuit and a signal monitoring circuit. The first switch circuit is electrically connected with the control circuit, and the first switch circuit is configured to execute turn-on and turn-off in response to an electric signal output by the control circuit; the second switch circuit is electrically connected with the first switch circuit, the signal monitoring circuit and the first switch, the second switch circuit is configured to respond to an on-off state of the first switch circuit and an electric signal output by the signal monitoring circuit to execute on and off, and the on-off state of the first switch circuit comprises an on state and an off state; the switch driving circuit is configured to drive the first switch to be switched on in response to the control circuit outputting a first electric signal for switching on the first switch circuit to the first switch circuit and the signal monitoring circuit outputting a second electric signal for controlling the switching on of the second switch circuit to the second switch circuit.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a switch drive circuit, a battery management system, a battery pack, and an electrical device. Background Technology

[0002] In battery packs, analog front-end (AFE) chips are commonly used to collect information such as cell voltage and temperature, and can output control signals to control the conduction and cutoff of charging and discharging switches. However, in practical applications, due to factors such as external high-voltage backflow and electromagnetic interference, the signals output by the AFE chip may be interfered with, resulting in signal jitter or false triggering. This can cause the charging and / or discharging switches to be in a weak conduction state, leading to system failure or even safety hazards. Summary of the Invention

[0003] This application provides a switch drive circuit, a battery management system, a battery pack, and an electrical device, which can reduce the risk of switch damage and improve safety and reliability.

[0004] In a first aspect, embodiments of this application provide a switch driving circuit, including a first switch. The switch driving circuit includes a control circuit, a signal monitoring circuit, a first switch circuit, and a second switch circuit. The first switch circuit is electrically connected to the control circuit and is configured to perform on / off operations in response to an electrical signal output by the control circuit. The second switch circuit is electrically connected to the first switch circuit, the signal monitoring circuit, and the first switch. The second switch circuit is configured to perform on / off operations in response to the on / off state of the first switch circuit and the electrical signal output by the signal monitoring circuit. The on / off state of the first switch circuit includes an on state and an off state. The switch driving circuit is configured to drive the first switch to turn on in response to the control circuit outputting a first electrical signal to the first switch circuit to turn on the first switch circuit, and the signal monitoring circuit outputting a second electrical signal to the second switch circuit to control the second switch circuit to turn on the second switch circuit.

[0005] The above process implements a dual verification mechanism for the signal driving the first switch, providing strong anti-interference capabilities and improving the overall safety and reliability of the switch drive circuit system. Thus, in application scenarios where signal monitoring circuits include AFE chips, even if the AFE chip experiences signal jitter or false triggering due to external high-voltage backflow, electromagnetic interference, or other factors, the dual verification mechanism will ensure the first switch remains off, preventing it from being in a weak conduction state. This reduces the risk of damage to the first switch and improves the system's safety and reliability.

[0006] In one or more embodiments, the switch driving circuit includes a third switch circuit electrically connected to a signal monitoring circuit, a first switch circuit, and a second switch circuit. The third switch circuit includes an energy storage element, a first diode, and a second switch. The third switch circuit is configured to: in response to a control circuit outputting a first electrical signal to the first switch circuit to turn on the first switch circuit, and the signal monitoring circuit outputting a second electrical signal to the second switch circuit to control the second switch circuit to turn on, the energy storage element performs a charging operation; and / or, in response to the control circuit outputting a third electrical signal to the first switch circuit to turn off the first switch circuit, the second switch turns on, and parasitic charges in the energy storage element and the second switch circuit are discharged through the second switch; and / or, in response to the signal monitoring circuit outputting a fourth electrical signal to the second switch circuit to turn off the second switch circuit, the second switch turns on, and parasitic charges in the energy storage element and the second switch circuit are discharged through the second switch. Parasitic charges in the energy storage element and the second switching circuit are discharged through the second switch, enabling the second switching circuit to turn off quickly, thus allowing the first switch to turn off quickly as well. This helps reduce switching losses in both the second and first switching circuits, thereby improving efficiency. Furthermore, by adjusting the parameters of the energy storage element, the switching speeds of the second and first switching circuits can be flexibly adjusted according to requirements.

[0007] In one or more embodiments, the first switching circuit includes a third switch, a first resistor, and a second resistor. A first terminal of the third switch is electrically connected to a first terminal of the first resistor and a first terminal of the second resistor. A second terminal of the third switch and a second terminal of the first resistor are electrically connected to a ground terminal. A second terminal of the second resistor is electrically connected to a control circuit. The second switching circuit includes a fourth switch, a third resistor, and a fourth resistor. A first terminal of the fourth switch is electrically connected to a first terminal of the third resistor and a first terminal of the fourth resistor. A second terminal of the third resistor is electrically connected to a third terminal of the third switch. A second terminal of the fourth switch is electrically connected to a second terminal of the fourth resistor and a signal monitoring circuit. A third terminal of the fourth switch is electrically connected to the first switch.

[0008] In one or more embodiments, the first end of the energy storage element is electrically connected to the second end of the third resistor and the third end of the third switch; the second end of the energy storage element is electrically connected to the cathode of the first diode and the first end of the second switch; the anode of the first diode is electrically connected to the first end of the fourth switch, the first end of the third resistor, the first end of the fourth resistor and the second end of the second switch; and the third end of the second switch is electrically connected to the second end of the fourth switch, the second end of the fourth resistor and the signal monitoring circuit. In one or more embodiments, the second switch is an NPN transistor or an N-type FET, the third switch is an NPN transistor or an N-type FET, and the fourth switch is a PNP transistor or a P-type FET.

[0009] In one or more embodiments, the switch driving circuit includes a fourth switch circuit electrically connected to the second switch circuit and the first switch. The fourth switch circuit is configured to: turn on in response to a control circuit outputting a third electrical signal to the first switch circuit to turn off the first switch circuit, thereby discharging parasitic charges of the first switch through the fourth switch circuit; and / or, turn on in response to a signal monitoring circuit outputting a fourth electrical signal to the second switch circuit to turn off the second switch circuit, thereby discharging parasitic charges of the first switch through the fourth switch circuit.

[0010] The parasitic charge of the first switch is discharged through the fourth switch circuit, which helps to achieve rapid discharge of the first switch and thus rapid shutdown, thereby improving efficiency and enabling flexible adjustment of the switching speed of the first switch according to needs.

[0011] In one or more embodiments, the fourth switching circuit includes a fifth switch, a fifth resistor, a sixth resistor, and a second diode. The first terminal of the fifth switch is electrically connected to the first terminal of the fifth resistor, the anode of the second diode, and the second switching circuit. The second terminal of the fifth switch is electrically connected to the cathode of the second diode and the first terminal of the first switch. The third terminal of the fifth switch is electrically connected to the first terminal of the sixth resistor. The second terminals of the fifth resistor, the sixth resistor, and the first switch are configured to be electrically connected to the positive terminal of the battery module. The third terminal of the first switch is configured to be electrically connected to the positive output terminal of the battery pack.

[0012] In one or more embodiments, the fifth switch is a PNP transistor or a P-type FET.

[0013] In one or more embodiments, the switch driving circuit further includes: a seventh resistor electrically connected between the second switch circuit and the fourth switch circuit; and / or an eighth resistor electrically connected between the first terminal of the fifth switch and the anode of the second diode; and / or a ninth resistor electrically connected between the second terminal of the first switch and the cathode of the second diode; and / or a tenth resistor electrically connected between the first terminal of the first switch and the fourth switch circuit.

[0014] Secondly, embodiments of this application provide a battery management system, including a charging switch, a discharging switch, and at least one switch driving circuit as described in the first aspect, wherein the first switch includes a charging switch and / or a discharging switch. The first switch is configured to be located between the positive terminal of the battery module and the positive output terminal of the battery pack.

[0015] Thirdly, embodiments of this application provide a battery pack, including a battery module, a wiring harness, a connector, and a battery management system as described in the second aspect. The connector includes a positive output terminal and a negative output terminal, and the battery management system connects the positive output terminal and the negative output terminal via the wiring harness.

[0016] Fourthly, embodiments of this application provide an electrical device, including a load and a battery pack as described in the third aspect. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0018] Figure 1 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 1 ; Figure 2 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 2 ; Figure 3 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 3 ; Figure 4 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 4 ; Figure 5 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 5 ; Figure 6 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 6 ; Figure 7 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 7 ; Figure 8 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 8 ; Figure 9 This is a schematic diagram of the switch driving circuit provided in the embodiments of this application. Figure 9 ; Figure 10 This is a schematic diagram of the battery pack provided in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0020] It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements between them.

[0021] Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0022] Currently, in battery packs, an AFE chip can drive a first switch to turn on or off, which includes a charging switch and / or a discharging switch. However, in practical applications, due to factors such as external high-voltage backflow and electromagnetic interference, the signal output by the AFE chip may be interfered with, resulting in signal jitter or false triggering. This can cause the first switch to be in a weak conducting state, leading to system failure or even safety hazards.

[0023] The charging switch and discharging switch are connected in series between the positive terminal of the battery module and the positive output terminal of the battery pack. The AFE chip drives the charging switch to turn on or off. The charging switch and discharging switch are MOSFETs.

[0024] The AFE chip drives the charging switch to turn off, and the discharging switch is also in the off state. The gate voltage of the charging switch is 0V, and the gate-source voltage (i.e., the voltage difference between the gate and source) of the charging switch is 0V. At this time, if a high voltage appears at the positive output terminal of the battery pack, causing the voltage at the positive output terminal of the battery pack to be greater than the voltage at the positive terminal of the battery module. For example, if the positive output terminal of the battery pack is electrically connected to a charger, and the output voltage of the charger is greater than the voltage at the positive terminal of the battery module; or if the battery pack is used in an electric vehicle, and the electric vehicle is going downhill or braking, both of these will cause a high voltage to appear at the positive output terminal of the battery pack. The voltage at the positive output terminal of the battery pack is coupled to the AFE chip through the parasitic capacitance between the source and gate of the discharging switch. This situation is called external high voltage backflow. The signal output by the AFE chip may be interfered with, resulting in signal jitter or false triggering, which may cause the gate voltage of the charging switch to be greater than 0V, such as 2V or 3V. If the gate-source voltage of the charging switch is greater than 0V but less than the turn-on voltage, the charging switch is in a weak conduction state, that is, an incomplete conduction state. The charging switch has a relatively high internal resistance, ranging from a few ohms to tens of ohms, and generates a large amount of heat. Under such circumstances, the charging switch is prone to damage, which can lead to system failure or even safety hazards.

[0025] For the reasons mentioned above, this application provides a switch driving circuit that, by combining a control circuit and a signal monitoring circuit for dual control of the first switch, can effectively reduce the risk of the switch being damaged and improve safety and reliability.

[0026] Figure 1This is a schematic diagram of the block diagram of the switch driving circuit provided in an embodiment of this application. Figure 1 As shown, the switch driving circuit 100 includes a first switch Q1, a control circuit 10, a signal monitoring circuit 20, a first switch circuit 30, and a second switch circuit 40. The first switch circuit 30 is electrically connected to the control circuit 10, and the second switch circuit 40 is electrically connected to the first switch circuit 30, the signal monitoring circuit 20, and the first switch Q1.

[0027] The first switching circuit 30 is configured to turn on and off in response to an electrical signal output by the control circuit 10. The second switching circuit 40 is configured to turn on and off in response to the on / off state of the first switching circuit 30 and an electrical signal output by the signal monitoring circuit 20, wherein the on / off state of the first switching circuit 30 includes an on state and an off state. The switch driving circuit 100 is configured to drive the first switch Q1 to turn on in response to the control circuit 10 outputting a first electrical signal to the first switching circuit 30 to turn on the first switching circuit 30, and the signal monitoring circuit 20 outputting a second electrical signal to the second switching circuit 40 to control the turn-on of the second switching circuit 40.

[0028] It is evident that, in order to drive the first switch Q1 to conduct, the following two conditions must be met simultaneously: (i) the control circuit 10 outputs a first electrical signal to the first switch circuit 30; and (ii) the signal monitoring circuit 20 outputs a second electrical signal to the second switch circuit 40. This achieves a dual verification mechanism for the signal driving the first switch Q1, providing strong anti-interference capabilities and improving the overall safety and reliability of the switch drive circuit 100 system. Thus, in application scenarios where the signal monitoring circuit 20 includes an AFE chip, even if the AFE chip experiences signal jitter or false triggering due to external high-voltage backflow, electromagnetic interference, or other factors, the dual verification mechanism (where only condition ii is met) will keep the first switch Q1 off. The first switch Q1 will not be in a weak conduction state, which helps reduce the risk of damage to the first switch Q1 and improves the system's safety and reliability.

[0029] Optionally or additionally, such as Figure 2 As shown, the switch drive circuit 100 includes a third switch circuit 50, which is electrically connected to the signal monitoring circuit 20, the first switch circuit 30, and the second switch circuit 40. The third switch circuit 50 includes an energy storage element C1, a first diode D1, and a second switch Q2.

[0030] The third switching circuit is configured such that: in response to the control circuit 10 outputting a first electrical signal to the first switching circuit 30 to turn on the first switching circuit 30, and the signal monitoring circuit 20 outputting a second electrical signal to the second switching circuit 40 to control the turn on of the second switching circuit 40, the energy storage element C1 performs a charging operation; and / or, in response to the control circuit 10 outputting a third electrical signal to the first switching circuit 30 to turn off the first switching circuit 30, the second switch Q2 is turned on, and the parasitic charge in the energy storage element C1 and the second switching circuit 40 is discharged through the second switch Q2; and / or, in response to the signal monitoring circuit 20 outputting a fourth electrical signal to the second switching circuit 40 to turn off the second switching circuit 40, the second switch Q2 is turned on, and the parasitic charge in the energy storage element C1 and the second switching circuit 40 is discharged through the second switch Q2.

[0031] Specifically, when the control circuit 10 outputs a first electrical signal to the first switching circuit 30 and the signal detection circuit 20 outputs a second electrical signal to the second switching circuit 40 to drive the first switch Q1 to turn on, the energy storage element C1 is charged. Subsequently, if it is necessary to drive the first switch Q1 to turn off, the control circuit 10 outputs a third electrical signal to the first switching circuit 30, and / or the signal detection circuit 20 outputs a fourth electrical signal to the second switching circuit 40, at least one of the first switching circuit 30 and the second switching circuit 40 is turned off. At this time, the energy storage element C1 releases electrical energy. The electrical energy released by the energy storage element C1 drives the second switch Q2 to turn on. The parasitic charge in the energy storage element C1 and the second switching circuit 40 is discharged through the second switch Q2, thereby enabling the second switching circuit 40 to turn off quickly, which in turn enables the first switch Q1 to turn off quickly. This helps reduce the switching losses of the second switching circuit 40 and the first switch Q1, thus improving efficiency. Furthermore, by adjusting the parameters of the energy storage element C1, the switching speed of the second switching circuit 40 and the first switch Q1 can be flexibly adjusted according to requirements.

[0032] Figure 3 An example is shown with Figure 2 The block diagram shown corresponds to one type of circuit structure. For example... Figure 3 As shown, the first switching circuit 30 may include a third switch Q3, a first resistor R1, and a second resistor R2. The first terminal of the third switch Q3 is electrically connected to the first terminal of the first resistor R1 and the first terminal of the second resistor R2. The second terminal of the third switch Q3 and the second terminal of the first resistor R1 are electrically connected to the ground terminal GND. The second terminal of the second resistor R2 is electrically connected to the control circuit 10.

[0033] Specifically, the voltage of the signal output from the control circuit 10 is divided by the first resistor R1 and the second resistor R2. This voltage division across the first resistor R1 drives the third switch Q3 to turn on. The first resistor R1 also discharges charge when the third switch Q3 is off, ensuring reliable switching off. Furthermore, the first resistor R1 prevents electrostatic discharge or interference from causing the third switch Q3 to mis-turn on.

[0034] Optionally or additionally, the second switching circuit 40 may include a fourth switch Q4, a third resistor R3 and a fourth resistor R4, wherein the first terminal of the fourth switch Q4 is electrically connected to the first terminal of the third resistor R3 and the first terminal of the fourth resistor R4, the second terminal of the third resistor R3 is electrically connected to the third terminal of the third switch Q3, the second terminal of the fourth switch Q4 is electrically connected to the second terminal of the fourth resistor R4 and the signal monitoring circuit 20, and the third terminal of the fourth switch Q4 is electrically connected to the first switch Q1.

[0035] Specifically, when the third switch Q3 is turned on, the voltage of the signal output from the signal monitoring circuit 20 is divided by the voltage of the third resistor R3 and the fourth resistor R4. This voltage division across the fourth resistor R4 drives the fourth switch Q4 to turn on. The fourth resistor R4 also discharges charge when the fourth switch Q4 is turned off, ensuring reliable turn-off of the fourth switch Q4. Furthermore, the fourth resistor R4 prevents electrostatic discharge or interference from causing the fourth switch Q4 to mis-turn on.

[0036] Optionally or additionally, the first end of the energy storage element C1 can be electrically connected to the second end of the third resistor R3 and the third end of the third switch Q3. The second end of the energy storage element C1 is electrically connected to the cathode of the first diode D1 and the first end of the second switch Q2. The anode of the first diode D1 is electrically connected to the first end of the fourth switch Q4, the first end of the third resistor R3, the first end of the fourth resistor R4, and the second end of the second switch Q2. The third end of the second switch Q2 is electrically connected to the second end of the fourth switch Q4, the second end of the fourth resistor R4, and the signal monitoring circuit 20.

[0037] Specifically, this embodiment uses energy storage element C1 as a capacitor as an example. The first diode D1 is used to provide a charging path for energy storage element C1 when the first drive switch Q1 is normally turned on; and when the first drive switch Q1 is normally turned off, the energy storage element C1 can only discharge to the second switch Q2 to drive the second switch Q2 to turn on, and then the parasitic charge in energy storage element C1 and the second switch circuit 40 is discharged through the second switch Q2.

[0038] In this embodiment, taking an NPN transistor as an example, a third NPN transistor as an example, and a fourth PNP transistor as an example. Specifically, the first terminal of the second switch Q2 is the base of the NPN transistor, the second terminal of the second switch Q2 is the emitter of the NPN transistor, and the third terminal of the second switch Q2 is the collector of the NPN transistor; the first terminal of the third switch Q3 is the base of the NPN transistor, the second terminal of the third switch Q3 is the emitter of the NPN transistor, and the third terminal of the third switch Q3 is the collector of the NPN transistor; the first terminal of the fourth switch Q4 is the base of the PNP transistor, the second terminal of the fourth switch Q4 is the emitter of the PNP transistor, and the third terminal of the fourth switch Q4 is the collector of the PNP transistor.

[0039] Optionally or additionally, the second switch Q2 can also be an N-type FET, and / or the third switch Q3 can also be an N-type FET, and / or the fourth switch Q4 can also be a P-type FET. For example, as Figure 4 As shown, the second switch Q2 is an N-type FET, the third switch Q3 is an N-type FET, and the fourth switch Q4 is a P-type FET.

[0040] The following are Figure 3 The working principle of the circuit structure shown will be explained.

[0041] (1) The process of driving the first switch Q1 to conduct is as follows: The control circuit 10 outputs a first electrical signal (high level in this embodiment), which acts on the third switch Q3 through the second resistor R2, and the third switch Q3 conducts. The signal monitoring circuit 20 outputs a second electrical signal (high level in this embodiment), which acts on the fourth switch Q4 after being divided by the third resistor R3 and the fourth resistor R4, and the fourth switch Q4 conducts. The second electrical signal acts on the first switch Q1 through the fourth switch Q4 to drive the first switch Q1 to conduct. In addition, after the signal monitoring circuit 20 outputs the second electrical signal, the second signal charges the first capacitor C1 through the fourth resistor R4 and the first diode D1.

[0042] (2) The process of driving the first switch Q1 to turn off includes the following three situations: In the first scenario: Control signal 10 outputs a third electrical signal (low level in this embodiment). This third electrical signal acts on the third switch Q3 through the second resistor R2. The third switch Q3 rapidly discharges parasitic charges through the first resistor R1, and then turns off. At this time, the energy storage element C1 discharges through the PN junction of the second switch Q2 and the third resistor R3, causing the second switch Q2 to conduct. The parasitic charges of the fourth switch Q4 are rapidly discharged through the conducting second switch Q2, and the fourth switch Q4 turns off. The second electrical signal no longer acts on the first switch Q1, and the first switch Q1 turns off.

[0043] In the second scenario: the signal monitoring circuit 20 outputs a fourth electrical signal (low level in this embodiment). The energy storage element C1 discharges through the PN junction of the second switch Q2 and the third resistor R3, causing the second switch Q2 to conduct. At this time, the parasitic charge of the fourth switch Q4 is rapidly discharged through the conducting second switch Q2, and the fourth switch Q4 is turned off. The second electrical signal no longer acts on the first switch Q1, and the first switch Q1 is turned off.

[0044] In the third scenario: control signal 10 outputs a third electrical signal, and signal monitoring circuit 20 outputs a fourth electrical signal. Combining the explanations of the first and second scenarios, both the third switch Q3 and the fourth switch Q4 are turned off. The second electrical signal no longer acts on the first switch Q1, and the first switch Q1 is turned off.

[0045] In summary, this achieves a dual verification mechanism for the signal driving the first switch Q1, providing strong anti-interference capabilities and improving the overall safety and reliability of the switch drive circuit 100 system. Thus, in application scenarios where the signal monitoring circuit 20 includes an AFE chip, even if the AFE chip experiences signal jitter or false triggering due to external high-voltage backflow, electromagnetic interference, or other factors, the dual verification mechanism (where only condition ii is met) will ensure that the first switch Q1 remains off, preventing it from being in a weak conducting state. This reduces the risk of damage to the first switch Q1 and improves the system's safety and reliability. Furthermore, the inclusion of a discharge circuit for the fourth switch Q4 not only enables rapid discharge and subsequent rapid turn-off to improve efficiency but also allows for flexible adjustment of the switching speed of the fourth switch Q4 according to requirements.

[0046] Optionally or additionally, such as Figure 5 As shown, the switch drive circuit 100 may include a fourth switch circuit 60, which is electrically connected to the second switch circuit 40 and the first switch Q1.

[0047] The fourth switching circuit 60 is configured to: in response to the control circuit 10 outputting a third electrical signal to the first switching circuit 30 to turn off the first switching circuit 30, the fourth switching circuit 60 is turned on, and the parasitic charge of the first switch Q1 is discharged through the fourth switching circuit 60; and / or, in response to the signal monitoring circuit 20 outputting a fourth electrical signal to the second switching circuit 40 to turn off the second switching circuit 40, the fourth switching circuit 60 is turned on, and the parasitic charge of the first switch Q1 is discharged through the fourth switching circuit 60.

[0048] Specifically, as described above, control signal 10 outputs a third electrical signal to the first switching circuit 30, and / or signal monitoring circuit 20 outputs a fourth electrical signal to the second switching circuit 40, both of which turn off the second switching circuit 40. In this case, the fourth switching circuit 60 is turned on, and the parasitic charge of the first switch Q1 is discharged through the fourth switching circuit 60, which facilitates the rapid discharge of the first switch Q1 and thus rapid turn-off, thereby improving efficiency and enabling flexible adjustment of the switching speed of the first switch Q1 as needed.

[0049] Figure 6 An example is shown in Figure 4 A schematic diagram of a circuit structure with a fourth switch circuit 60 added based on the circuit structure shown. (See diagram below.) Figure 6 As shown, the fourth switching circuit 60 includes a fifth switch Q5, a fifth resistor R5, a sixth resistor R6, and a second diode D2.

[0050] The first terminal of the fifth switch Q5 is electrically connected to the first terminal of the fifth resistor R5, the anode of the second diode D2, and the second switch circuit 40. The second terminal of the fifth switch Q5 is electrically connected to the cathode of the second diode D2 and the first terminal of the first switch Q1. The third terminal of the fifth switch Q5 is electrically connected to the first terminal of the sixth resistor R6. The second terminals of the fifth resistor R5, the sixth resistor R6, and the first switch Q1 are configured to be electrically connected to the positive terminal B+ of the battery module. The third terminal of the first switch Q1 is configured to be electrically connected to the positive output terminal P+ of the battery pack.

[0051] The second diode D2 is used to conduct unidirectionally when the fourth switch Q4 is turned on to drive the first switch Q1 to close, and to ensure that the parasitic charge of the first switch Q1 is discharged through the fifth switch Q5 when the fourth switch Q4 is turned off, without any abnormal voltage flowing back to the fourth switch Q4.

[0052] Specifically, when the fourth switch Q4 is turned off, the fifth switch Q5 is driven to turn on by the gate voltage of the first switch Q1. The parasitic charge of the first switch Q1 is discharged through the turned-on fifth switch Q5, so as to realize the rapid discharge of the first switch Q1 and thus the rapid turn-off, and to realize the flexible adjustment of the switching speed of the first switch Q1 according to the needs.

[0053] It is understood that in this embodiment, the fifth switch Q5 is a PNP transistor and the first switch Q1 is an N-type FET. Specifically, the first terminal of the fifth switch Q5 is the base of the PNP transistor, the second terminal is the emitter of the PNP transistor, and the third terminal is the collector of the PNP transistor; the first terminal of the first switch Q1 is the gate of the N-type FET, the second terminal is the source of the N-type FET, and the third terminal is the drain of the N-type FET.

[0054] Understandably, in Figure 6 In the illustrated scheme, the second electrical signal output by the signal monitoring circuit 20 to control the conduction of the fourth switch Q4 is at a high level. The signal monitoring circuit 20 can be an AFE chip, which integrates a charge pump to boost the voltage of the battery module and output it to the fourth switch Q4 in the form of a second electrical signal. In this case, the voltage value represented by the second electrical signal is a voltage value larger than the battery module voltage, for example, about 12V larger, thus driving the first switch Q1 to conduct. The first electrical signal output by the control circuit 10 to control the conduction of the third switch Q3 is also at a high level. The control circuit 10 can be a microcontroller unit (MCU), and the voltage value represented by this high level can be a voltage value between 2.0V and 3.3V.

[0055] Optionally or additionally, the first switch Q1 and the fifth switch Q5 can also be any other controllable switches. For example, in some embodiments, the fifth switch Q5 is a P-type FET.

[0056] Understandably, such as Figure 3 , Figure 4 and Figure 6 The hardware structure of the switch drive circuit 100 shown is only an example, and the switch drive circuit 100 may have more or fewer components than shown in the figure, may combine two or more components, or may have different component configurations.

[0057] For example, in some alternative embodiments, such as Figure 7 As shown, the switch drive circuit 100 may further include a seventh resistor R7, which is electrically connected between the second switch circuit 40 and the fourth switch circuit 60, that is, the seventh resistor R7 is electrically connected between the third terminal of the fourth switch Q4 and the anode of the second diode D2. The seventh resistor R7 is a current-limiting resistor.

[0058] Optionally or additionally, the switch drive circuit 100 may also include an eighth resistor R8, which is electrically connected between the first terminal of the fifth switch Q5 and the anode of the second diode D2.

[0059] Optionally or additionally, the switch drive circuit 100 may further include a ninth resistor R9, which is electrically connected between the second terminal of the first switch Q1 and the cathode of the second diode D2. The ninth resistor R9 is a bleeder resistor. When the gate voltage of the first switch Q1 decreases to a level that cannot drive the fifth switch Q5 to conduct, the fifth switch Q5 is turned off. At this time, the parasitic charge of the first switch Q1 is discharged through the ninth resistor R9.

[0060] Optionally or additionally, the switch drive circuit 100 may also include a tenth resistor R10, which is electrically connected between the first terminal of the first switch Q1 and the fourth switch circuit 60, that is, the tenth resistor R10 is electrically connected between the first terminal of the first switch Q1 and the cathode of the second diode D2.

[0061] Optionally or additionally, such as Figure 8 As shown, the switch driving circuit 100 may further include a first Zener diode Z1. The anode of the first Zener diode Z1 is electrically connected to the first terminal of the fourth switch Q4, and the cathode of the first Zener diode Z1 is electrically connected to the second terminal of the fourth switch Q4. The first Zener diode Z1 is used to ensure that there is no abnormal negative voltage between the first and second terminals of the fourth switch Q4, thereby reducing the risk of failure of the fourth switch Q4.

[0062] Optionally or additionally, the switch drive circuit 100 may further include a second Zener diode Z2, the anode of which is electrically connected to the second terminal of the first switch Q1, and the cathode of which is electrically connected to the first terminal of the first switch Q1. The second Zener diode Z2 is used to ensure that there is no abnormal positive voltage between the first and second terminals of the first switch Q1, thereby reducing the risk of failure of the first switch Q1.

[0063] exist Figures 1-8 In the illustrated embodiment, the first switch Q1 is located between the positive terminal B+ of the battery module and the positive output terminal P+ of the battery pack. In other embodiments, when the first switch Q1 is located between the negative terminal B- of the battery module and the negative output terminal P- of the battery pack, the method provided in this application embodiment can also be used to drive the first switch Q1 to be turned on or off. In this case, with... Figures 1-8 The embodiment shown differs in that the signal driving the second switching circuit 40 (i.e., driving the fourth switch Q4) is no longer output by the signal monitoring circuit 20, but by the power supply circuit 70. The power supply circuit 70 may include a voltage conversion circuit configured to be electrically connected to the battery module, boost or buck the voltage output by the battery module, and output a signal to turn the second switching circuit 40 on or off. In some alternative examples, the voltage conversion circuit may include a Buck circuit, a type of DC-DC converter used to convert a higher DC input voltage to a lower, adjustable DC output voltage. Other than the differences described above, Figure 9 The implementation process of the circuit structure shown is as follows: Figure 8 Similarly, to the extent that it is readily understood by those skilled in the art, it will not be elaborated upon here.

[0064] This application also provides a battery pack. For example... Figure 10As shown, the battery pack 10000 includes a battery management system 1000, a battery module 2000, and wiring harnesses and connectors 3000. The battery module 2000 comprises multiple cells connected in parallel, series, or a hybrid configuration, and is used to store and supply electrical energy. It is understood that a hybrid configuration includes both series and parallel connections.

[0065] Connector 3000 includes a positive output terminal P+ and a negative output terminal P-. The battery management system 1000 connects to the positive output terminal P+ and the negative output terminal P- via a wiring harness. Understandably, Figure 10 The connector 3000 shown illustrates at least some of the terminals. In other alternative examples, the connector 3000 may be provided with additional terminals, such as indicator signal terminals and communication terminals. The indicator signal terminals are used to indicate that the connector 3000 has been mated with a connector on the electrical device, and the communication terminals are used for communication between the battery pack 10000 and the electrical device. In one specific example, the connector 3000 is configured as an aviation connector.

[0066] The wiring harness includes communication wiring harnesses and power wiring harnesses. The communication wiring harness is used for signal transmission; for example, the wiring harness connected to the signal terminals of the battery pack 10000 is a communication wiring harness. The power wiring harness is used for power transmission; for example, the wiring harness connected to the positive output terminal P+ and the negative output terminal P- of the battery pack 10000 is a power wiring harness.

[0067] The Battery Management System (BMS) 1000 is powered by the battery module 2000. The BMS 1000 can monitor and control the charging and / or discharging of the battery module 2000 to manage the performance of the battery module 2000 and ensure electrical safety.

[0068] The battery management system 1000 includes a charging switch S1 and a discharging switch S2. The charging switch S1 and discharging switch S2 are located on the current path from the positive terminal B+ to the positive output terminal P+ of the battery module 2000; that is, the charging switch S1 and discharging switch S2 are connected in series and positioned between the positive terminal B+ and the positive output terminal P+ of the battery module 2000. The charging switch S1 and / or the discharging switch S2 can be configured as controllable switching elements; for example, both the charging switch S1 and the discharging switch S2 can be N-type FETs. It is understood that... Figure 10 Only one charging switch S1 and one discharging switch S2 are shown. If the battery pack 10000 requires a large current charging and discharging scenario, multiple charging switches S1 and multiple discharging switches S2 can be set to share the current. Multiple charging switches S1 are connected in parallel, and multiple discharging switches S2 are connected in parallel.

[0069] The battery management system 1000 includes at least one switch drive circuit 100 as described in any embodiment of this application. Figures 1 to 9 The first switch Q1 shown includes a charging switch S1 and / or a discharging switch S2. That is, each charging switch S1 in the battery pack 10000 can be configured as the first switch Q1, and each discharging switch S2 can be configured as the first switch Q1, so that the first switch Q1 can be driven to be turned on or off by the switch driving circuit 100.

[0070] Some embodiments of this application also provide an electrical device. This electrical device includes a load and the battery pack described above. The load includes electrical components on the electrical device such as motors, lights, horns, and instruments. The electrical device is a device that requires power from the battery pack. For example, the electrical device includes: unmanned aerial vehicles, energy storage products, power tools, electric vehicles (electric two-wheelers, electric tricycles), etc.

[0071] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0072] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A switch driving circuit, comprising a first switch, characterized in that, The switch driving circuit includes: Control circuits and signal monitoring circuits; A first switching circuit is electrically connected to the control circuit, and the first switching circuit is configured to perform on and off operations in response to an electrical signal output by the control circuit. The second switching circuit is electrically connected to the first switching circuit, the signal monitoring circuit, and the first switch. The second switching circuit is configured to perform on and off operations in response to the on / off state of the first switching circuit and the electrical signal output by the signal monitoring circuit. The on / off state of the first switching circuit includes an on state and an off state. The switch driving circuit is configured to drive the first switch to turn on in response to the control circuit outputting a first electrical signal to the first switch circuit to turn on the first switch circuit and the signal monitoring circuit outputting a second electrical signal to the second switch circuit to control the second switch circuit to turn on the second switch circuit.

2. The switch driving circuit according to claim 1, characterized in that, The switch driving circuit includes a third switch circuit, which is electrically connected to the signal monitoring circuit, the first switch circuit, and the second switch circuit. The third switch circuit includes an energy storage element, a first diode, and a second switch. The third switching circuit is configured as follows: In response to the control circuit outputting a first electrical signal to the first switching circuit to enable the first switching circuit, and the signal monitoring circuit outputting a second electrical signal to the second switching circuit to enable the second switching circuit, the energy storage element performs a charging operation; and / or In response to the control circuit outputting a third electrical signal to the first switching circuit to turn off the first switching circuit, the second switch turns on, and the parasitic charge in the energy storage element and the second switching circuit is discharged through the second switch; and / or In response to the signal monitoring circuit outputting a fourth electrical signal to the second switching circuit to turn off the second switching circuit, the second switch is turned on, and the parasitic charge in the energy storage element and the second switching circuit is discharged through the second switch.

3. The switch driving circuit according to claim 2, characterized in that, The first switching circuit includes: a third switch, a first resistor, and a second resistor. The first end of the third switch is electrically connected to the first end of the first resistor and the first end of the second resistor, the second end of the third switch and the second end of the first resistor are electrically connected to the ground terminal, and the second end of the second resistor is electrically connected to the control circuit. The second switching circuit includes: a fourth switch, a third resistor, and a fourth resistor. The first terminal of the fourth switch is electrically connected to the first terminal of the third resistor and the first terminal of the fourth resistor. The second terminal of the third resistor is electrically connected to the third terminal of the third switch. The second terminal of the fourth switch is electrically connected to the second terminal of the fourth resistor and the signal monitoring circuit. The third terminal of the fourth switch is electrically connected to the first switch.

4. The switch driving circuit according to claim 3, characterized in that, The first end of the energy storage element is electrically connected to the second end of the third resistor and the third end of the third switch. The second end of the energy storage element is electrically connected to the cathode of the first diode and the first end of the second switch. The anode of the first diode is electrically connected to the first end of the fourth switch, the first end of the third resistor, the first end of the fourth resistor, and the second end of the second switch. The third end of the second switch is electrically connected to the second end of the fourth switch, the second end of the fourth resistor, and the signal monitoring circuit.

5. The switch driving circuit according to claim 3 or 4, characterized in that, The second switch is an NPN transistor or an N-type FET, the third switch is an NPN transistor or an N-type FET, and the fourth switch is a PNP transistor or a P-type FET.

6. The switch drive circuit according to any one of claims 1-5, characterized in that, The switch driving circuit includes a fourth switch circuit, which is electrically connected to the second switch circuit and the first switch. The fourth switching circuit is configured to: in response to the control circuit outputting a third electrical signal to the first switching circuit to turn off the first switching circuit, the fourth switching circuit is turned on, and the parasitic charge of the first switch is discharged through the fourth switching circuit; and / or In response to the signal monitoring circuit outputting a fourth electrical signal to the second switching circuit to turn off the second switching circuit, the fourth switching circuit is turned on, and the parasitic charge of the first switch is discharged through the fourth switching circuit.

7. The switch driving circuit according to claim 6, characterized in that, The fourth switching circuit includes a fifth switch, a fifth resistor, a sixth resistor, and a second diode; The first terminal of the fifth switch is electrically connected to the first terminal of the fifth resistor, the anode of the second diode, and the second switch circuit. The second terminal of the fifth switch is electrically connected to the cathode of the second diode and the first terminal of the first switch. The third terminal of the fifth switch is electrically connected to the first terminal of the sixth resistor. The second terminals of the fifth resistor, the sixth resistor, and the first switch are configured to be electrically connected to the positive terminal of the battery module. The third terminal of the first switch is configured to be electrically connected to the positive output terminal of the battery pack.

8. The switch driving circuit according to claim 7, characterized in that, The fifth switch is a PNP transistor or a P-type FET.

9. The switch driving circuit according to claim 7 or 8, characterized in that, Also includes: The seventh resistor is electrically connected between the second switching circuit and the fourth switching circuit; And / or, an eighth resistor, which is electrically connected between the first terminal of the fifth switch and the anode of the second diode; And / or, a ninth resistor, which is electrically connected between the second terminal of the first switch and the cathode of the second diode; And / or, a tenth resistor, which is electrically connected between the first terminal of the first switch and the fourth switch circuit.

10. A battery management system, characterized in that, The device includes a charging switch, a discharging switch, and at least one switch driving circuit as described in any one of claims 1-9, wherein the first switch includes the charging switch and / or the discharging switch; The first switch is configured to be located between the positive terminal of the battery module and the positive output terminal of the battery pack.

11. A battery pack, characterized in that, Includes battery modules, wiring harnesses, connectors, and the battery management system as described in claim 10; The connector includes a positive output terminal and a negative output terminal, and the battery management system connects the positive output terminal and the negative output terminal through the wiring harness.

12. An electrical appliance, characterized in that, Includes the load and the battery pack as described in claim 11.

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