Switch control device, battery management system, battery pack and electric device

Abstract

A switch control device comprises a first switch, a second switch, a controller, a control circuit and a driving circuit. The control circuit is electrically connected with the first switch, the driving circuit and the controller, and the driving circuit is electrically connected with the first switch and the second switch; the control circuit is configured to transmit a control signal to the drive circuit to turn off the second switch in response to reset of the controller and adhesion of the first switch.

Description

Technical Field

[0001] The present application relates to the field of battery management technology, and in particular to a switch control device, a battery management system, a battery pack and an electrical device. Background Art

[0002] A battery management system (BMS) can manage and control battery modules. For example, a control device of the BMS controls the charging and discharging of battery modules. How to ensure reliable control of the charging and discharging of battery modules has always been a problem that technicians in this field have devoted themselves to studying. Summary of the invention

[0003] The embodiments of the present application provide a switch control device, a battery management system, a battery pack, and an electrical device, which can reliably implement power-off protection and improve the safety of the battery pack and the electrical device.

[0004] In a first aspect, an embodiment of the present application provides a switch control device, comprising: a first switch, a second switch, a controller, a control circuit and a drive circuit; the control circuit is electrically connected to the first switch, the drive circuit and the controller, respectively, and the drive circuit is electrically connected to the first switch and the second switch, respectively; the control circuit is constructed such that: in response to a reset of the controller and a sticking of the first switch, the control circuit transmits a control signal to the drive circuit to turn off the second switch.

[0005] According to the switch control device provided in the embodiment of the present application, when the controller is reset and a sticking fault occurs in the first switch, the control circuit transmits a control signal to the drive circuit, and the drive circuit controls the second switch to disconnect. In this way, effective power outage can be reliably achieved, thereby achieving power-off protection and improving the safety of the battery pack and electrical devices.

[0006] In a possible implementation of the first aspect, the control circuit includes a first control circuit and a second control circuit electrically connected to the first control circuit; the first control circuit is electrically connected to the controller, and the second control circuit is electrically connected to the second switch through the drive circuit; the first control circuit is configured to transmit a first signal to the second control circuit in response to a reset of the controller; the second control circuit is configured to detect the state of the first switch, and is configured to transmit a control signal to the drive circuit in response to the first switch being stuck and the second control circuit receiving the first signal to turn off the second switch.

[0007] In a possible implementation of the first aspect, the switch control device includes a first power supply and a second power supply, and the second control circuit includes a detection unit, a pull-down unit, a first OR gate unit and a signal conversion unit; the detection unit is electrically connected to the first switch and the first power supply and the second power supply, and the detection unit is constructed to: output a second signal in response to the first switch being stuck; the pull-down unit is electrically connected to the third power supply and the controller, and is constructed to: output a third signal in response to the controller being reset; the first OR gate unit is electrically connected to the detection unit and the pull-down unit, and is constructed to: output a fourth signal based on the second signal and the third signal; the signal conversion unit is electrically connected to the first OR gate unit, and is constructed to convert the fourth signal into a fifth signal so that the drive circuit controls the second switch to disconnect.

[0008] In a possible implementation of the first aspect, the second control circuit also includes a second OR gate unit; the two input ends of the second OR gate unit are electrically connected to the output end of the signal conversion unit and the controller respectively; the second OR gate unit is constructed as follows: in response to any one input end of the second OR gate unit being a high level, the second OR gate unit outputs a high level so that the drive circuit controls the second switch to disconnect.

[0009] In a possible implementation of the first aspect, the detection unit includes an electrical isolation element, a first resistor, and a second resistor; an input end of the electrical isolation element, the first resistor, and a feedback contact of the first switch are connected in series between a first power supply and a ground terminal, and an output end of the electrical isolation element and the second resistor are connected in series between a second power supply and a ground terminal; the second power supply is electrically connected to the first OR gate unit through the second resistor;

[0010] Alternatively, the detection unit includes a first transistor, a third resistor, a fourth resistor and a fifth resistor; the third resistor and the feedback contact of the first switch are connected in series between the control end of the first transistor and the first power supply, and the fourth resistor is electrically connected between the first end and the control end of the first transistor; the first end of the first transistor is electrically connected to the ground end, the second end of the first transistor is electrically connected to the second power supply through the fifth resistor, and the second end of the first transistor is electrically connected to the first OR gate unit.

[0011] In a possible implementation manner of the first aspect, the electrical isolation element includes a photocoupler, a photorelay, or a photothyristor; or the first transistor includes an N-type FET or an NPN transistor.

[0012] In a possible implementation of the first aspect, the signal conversion unit includes a second transistor, a sixth resistor and a seventh resistor; the control end of the second transistor is electrically connected to the output end of the first OR gate unit through the sixth resistor, the first end of the second transistor is electrically connected to the third power supply, and the second end of the second transistor is the output end of the signal conversion unit; the seventh resistor is arranged between the first end of the second transistor and the control end thereof, and the third power supply is electrically connected to the output end of the signal conversion unit through the sixth resistor and the seventh resistor.

[0013] In a possible implementation of the first aspect, the signal conversion unit also includes a first capacitor; the seventh resistor is connected in parallel with the first capacitor, the second transistor, the first end of the first capacitor, the first end of the sixth resistor and the first end of the seventh resistor are electrically connected to the first node, the second end of the sixth resistor is electrically connected to the output end of the first OR gate unit, and the first end of the second transistor, the second end of the first capacitor and the second end of the seventh resistor are all electrically connected to the third power supply.

[0014] In a possible implementation manner of the first aspect, the second transistor includes a P-type FET or a PNP-type triode.

[0015] In a possible implementation of the first aspect, the pull-down unit includes a third transistor, an eighth resistor and a ninth resistor; the control end of the third transistor is electrically connected to the first control circuit, the eighth resistor is electrically connected between the control end and the ground end of the third transistor, the first end of the third transistor is electrically connected to the ground end, the second end of the third transistor is electrically connected to the fourth power supply through the ninth resistor, and the fourth power supply is electrically connected to the input end of the first OR gate unit through the ninth resistor.

[0016] In a possible implementation manner of the first aspect, the third transistor includes an N-type FET or an NPN-type triode.

[0017] In a possible implementation of the first aspect, the switch control device includes a fifth power supply, and the first control circuit includes a fourth transistor, a tenth resistor and an eleventh resistor; the control end of the fourth transistor is electrically connected to the controller through the tenth resistor, the first end of the fourth transistor is electrically connected to the fifth power supply, and the second end of the fourth transistor is electrically connected to the second control circuit; the eleventh resistor is electrically connected between the control end of the fourth transistor and the first end of the fourth transistor.

[0018] In a second aspect, based on the same inventive concept, an embodiment of the present application further provides a battery management system, comprising a switch driving device as described in the first aspect or any one embodiment of the first aspect.

[0019] In the third aspect, based on the same inventive concept, the embodiment of the present application also provides a battery pack, including a battery module, and a battery management system as described in the embodiment of the second aspect.

[0020] In a fourth aspect, based on the same inventive concept, an embodiment of the present application further provides an electrical device, comprising a battery pack as described in the embodiment of the third aspect.

[0021] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present application will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features and the accompanying drawings are not drawn to scale.

[0023] Figure 1 A schematic diagram showing a structure of an electric device provided in an embodiment of the present application is shown;

[0024] Figure 2 A schematic diagram showing the structure of a battery pack provided in an embodiment of the present application is shown;

[0025] Figure 3 A schematic diagram of the structure of a battery management system provided in an embodiment of the present application is shown;

[0026] Figure 4 A schematic diagram showing a circuit structure of a switch control device provided in an embodiment of the present application is shown;

[0027] Figure 5 Another circuit structure schematic diagram of the switch control device provided in the embodiment of the present application is shown;

[0028] Figure 6 Another circuit structure diagram of the switch control device provided in the embodiment of the present application is shown;

[0029] Figure 7 Another circuit structure diagram of the switch control device provided in the embodiment of the present application is shown;

[0030] Figure 8 Another circuit structure diagram of the switch control device provided in the embodiment of the present application is shown;

[0031] Fig. 9 Another circuit structure diagram of the switch control device provided in the embodiment of the present application is shown;

[0032] Fig.10 Another circuit structure diagram of the switch control device provided in the embodiment of the present application is shown;

[0033] Fig.11Another circuit structure diagram of the switch control device provided in the embodiment of the present application is shown;

[0034] Fig.12 Another circuit structure diagram of the switch control device provided in the embodiment of the present application is shown;

[0035] Fig.13 Another circuit structure schematic diagram of the switch control device provided in the embodiment of the present application is shown. DETAILED DESCRIPTION

[0036] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only constructed to explain the present application and are not constructed to limit the present application.

[0037] In the present application, when an element is stated to be “connected” or “electrically connected” to another element, it may be directly connected to the other element or one or more intervening elements may be present therebetween.

[0038] The implementation methods and specific features in the implementation methods provided in the examples of the present application can be combined with each other if there is no contradiction.

[0039] Energy Storage System (ESS) is a system that stores electrical energy and supplies power to the outside. It is widely used in the fields of household energy storage, industrial and commercial energy storage, uninterruptible power supply, etc. Energy storage system usually includes battery module and battery management system (BMS). The battery management system includes micro control unit (MCU). Relays are usually set on the charge and discharge path of the battery module. When the relay is closed, the charge and / or discharge path of the battery module is turned on. When the relay is disconnected, the charge and / or discharge path of the battery module is disconnected.

[0040] In order to ensure the safety of the system, when the MCU of the BMS is reset, the relay needs to be disconnected to prohibit the battery module from charging or discharging. However, the inventors found that in this case, disconnecting the relay is a load cut-off, and there is a large current on the path where the relay is located. Cutting off at this time is likely to cause the relay to stick, and then the power cannot be reliably cut off, which poses a greater safety risk.

[0041] In response to the above technical problems, the present application provides a switch control device, a battery management system, a battery pack and an electrical device, which can achieve power-off protection to improve safety.

[0042] like Figure 1 As shown, the electric device 3000 in this embodiment includes a battery pack 1000, and the electric device 3000 includes a load 2000. The battery pack 1000 is electrically connected to the load 2000 to provide electric energy to the load 2000.

[0043] In one application scenario, the power-consuming device 3000 is electrically connected to a charging device (not shown in the figure), and the charging device charges the battery pack 1000 .

[0044] In this application, the power-consuming device 3000 includes but is not limited to power tools, electric vehicles, drones, energy storage devices, smart doors, etc. In some specific implementations, power tools include electric drills, electric saws, etc., electric vehicles include electric cars, electric motorcycles, electric bicycles, etc., and energy storage devices include household energy storage devices, industrial and commercial energy storage devices, uninterruptible power supplies, etc.

[0045] like Figure 2 As shown, the battery pack 1000 includes a battery management system 100 and a battery module 200. The battery management system 100 is electrically connected to the battery module 200. The battery module 200 includes a plurality of battery cells connected in series, in parallel or in mixed connection. Mixed connection means that the electrical connection between the battery cells includes series connection and parallel connection.

[0046] The battery management system 100 detects the parameters of the battery module 200, including voltage, current, temperature, etc., and controls the charging and discharging of the battery module 200. The battery management system 100 controls the discharge switch to be turned on, and the battery module 200 supplies power to the load 2000. The battery management system 100 controls the charging switch to be turned on, and the charging device charges the battery module 200. When the battery management system 100 detects that the battery module 200 has an overvoltage, undervoltage, overcurrent, overtemperature, etc. fault, the battery management system 100 disconnects the charging and discharging of the battery module.

[0047] like Figure 3 As shown, the battery management system 100 includes a switch control device 10. The switch control device 10 controls the charge and discharge of the battery module.

[0048] like Figure 4 As shown, the switch control device 10 includes a first switch Q1 , a second switch Q2 , a controller 1 , a control circuit 2 and a drive circuit 3 .

[0049] The control circuit 2 is electrically connected to the first switch Q1 , the driving circuit 3 and the controller 1 , respectively. The driving circuit 3 is electrically connected to the first switch Q1 and the second switch Q2 , respectively.

[0050] The control circuit 2 is configured to transmit a control signal to the drive circuit 3 to turn off the second switch Q2 in response to the controller 1 being reset and the first switch Q1 being stuck.

[0051] After the second switch Q2 is turned off, the main circuit is disconnected, the battery module no longer discharges, or the charging device no longer charges the battery module. The main circuit is a power circuit for transmitting electrical energy. In this application, the main circuit includes a charging circuit and / or a discharging circuit of the battery module.

[0052] The first switch Q1 and the second switch Q2 are located on the discharge path and / or the charge path of the battery module. Exemplarily, the first switch Q1 and the second switch Q2 are connected in series, and the first switch Q1 and the second switch Q2 are both electrically connected to the battery module.

[0053] In some embodiments, the first switch Q1 includes a relay, which is opened or closed in response to the control of an electrical signal. The second switch Q2 includes a circuit breaker, which is opened in response to the control of an electrical signal, and the circuit breaker is closed or opened under manual control. For example, when maintenance is required, the second switch Q2 is manually opened, and after the maintenance is completed, the second switch Q2 is manually closed.

[0054] According to the switch control device provided in the embodiment of the present application, when the controller is reset and a sticking fault occurs in the first switch, the control circuit transmits a control signal to the drive circuit, and the drive circuit drives the second switch to disconnect. In this way, the main circuit can be reliably disconnected, and power-off protection can be achieved to improve safety.

[0055] As an example, Figure 4 As shown, the first pole of the battery module 200 is electrically connected to the first port P+ through the first switch Q1 and the second switch Q2, and the second pole of the battery module 200 is electrically connected to the second port P-, and the first port P+ and the second port P- are used to connect a load or a charging device. As an example, the first pole of the battery module is the positive pole B+ of the battery module, the second pole of the battery module is the negative pole B- of the battery module, the first port P+ is the positive discharge output terminal of the battery pack, and the second port P- is the negative discharge output terminal of the battery pack.

[0056] When the first switch Q1 and the second switch Q2 are closed, the battery module 200 is charged or discharged. When at least one of the first switch Q1 and the second switch Q2 is opened, the battery module 200 is no longer charged or discharged.

[0057] In some embodiments, the second pole of the battery module 200 is electrically connected to the second port P- through the second switch Q2. The two second switches Q2 are disconnected in response to the electrical control signal of the drive circuit 3, so that the first port P+ and the second port P- are both disconnected from the battery module 200 to better achieve power-off protection.

[0058] Understandably, Figure 4 Only one connection relationship between the first switch and the second switch is shown. In other embodiments, for example, the first switch is connected between the battery module and the second switch.

[0059] The controller can be an integrated circuit chip with signal processing capabilities. In some embodiments, the controller is a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc. For example, the general-purpose processor is a microprocessor (MCU). In other embodiments, the controller is a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0060] The controller 1 is electrically connected to the control circuit 2 . When the controller 1 is reset, the control circuit 2 receives a signal indicating that the controller 1 is reset.

[0061] As an example, Figure 5 As shown, the controller 1 and the control circuit 2 are electrically connected to the watchdog circuit 4. The watchdog circuit 4 is used to transmit the controller reset signal RSTB. For example, the watchdog circuit 4 is turned on when the power is on, and the controller 1 realizes the dog feeding function through the level change of the input output (IO) pin. Once the controller 1 is abnormal and the dog feeding timeout occurs, the watchdog circuit 4 will send the controller reset signal RSTB to the controller 1 to control the controller 1 to reset, and send the controller reset signal RSTB to the control circuit 2 at the same time. Exemplarily, the reset signal RSTB is low.

[0062] Exemplarily, the drive circuit 3 includes an enable pin (pin_EN), and the control circuit 2 is electrically connected to the enable pin of the drive circuit 3. When the controller 1 is reset and the first switch Q1 is stuck, the control signal transmitted by the control circuit 2 to the drive circuit 3 includes an enable signal, which is used to instruct the drive circuit 3 to output a drive signal to disconnect the second switch Q2. For example, the control signal is a high level.

[0063] Exemplarily, when the controller 1 operates normally and / or the first switch Q1 does not stick, the control circuit 2 does not transmit a control signal to the drive circuit 3, or the control circuit 2 transmits other signals to the drive circuit 3, and the other signals do not include the above-mentioned enable signal.

[0064] In some optional implementations, the driving circuit 3 includes a high-side driver chip.

[0065] In some optional implementations, such as Figure 6 As shown, the control circuit includes a first control circuit 21 and a second control circuit 22 electrically connected to the first control circuit 21 .

[0066] The first control circuit 21 is electrically connected to the controller 1 , and the second control circuit 22 is electrically connected to the second switch Q2 via the driving circuit 3 .

[0067] The first control circuit 21 is configured to transmit a first signal to the second control circuit 22 in response to the controller 1 being reset.

[0068] The second control circuit 22 is configured to detect the state of the first switch Q1. When sticking occurs in the first switch Q1 and the second control circuit 22 receives the first signal, the second control circuit 22 transmits a control signal to the drive circuit 3 to turn off the second switch Q2.

[0069] Exemplarily, after receiving the reset signal transmitted by the controller, the first control circuit 21 transmits the first signal to the second control circuit 22. For example, the controller reset signal is at a low level and the first signal is at a high level. Here, the "first signal" is also used to indicate that the controller 1 is in a reset state. It is understandable that the first control circuit 21 is also used to detect whether the controller is reset.

[0070] In this embodiment, by setting up a first control circuit and a second control circuit, it is possible to detect whether the controller is reset and whether the first switch is stuck. Then, when the controller is reset and the first switch is stuck, a control signal is transmitted to the drive circuit to disconnect the second switch, thereby achieving power-off protection and improving safety.

[0071] As an example, the first control circuit 21 is integrated into a first chip, and the second control circuit 22 is integrated into a second chip.

[0072] As another example, the first control circuit 21 and the second control circuit 22 are integrated into a third chip.

[0073] Exemplarily, the first control circuit 21 is electrically connected to the drive circuit 3, and the drive circuit 3 is electrically connected to the first switch Q1. When the controller 1 works normally, the first control circuit 21 transmits a control signal to the drive circuit 3 to normally open or close the first switch Q1.

[0074] Exemplarily, the first control circuit 21 and the second control circuit 22 are electrically connected to different enable pins of the driving circuit 3 .

[0075] In some optional implementations, such as Figure 7 As shown, the switch control device includes a first power source V1 and a second power source V2 , and the second control circuit 22 includes a detection unit 221 , a pull-down unit 222 , a first OR gate unit 223 and a signal conversion unit 224 .

[0076] The detection unit 221 is electrically connected to the first switch Q1 and the first power source V1 and the second power source V2. The detection unit 221 is used to detect whether the first switch Q1 is stuck, and output a second signal when the first switch Q1 is stuck.

[0077] The pull-down unit 222 is electrically connected to the third power source V3 and the controller 1 , and is configured to output a third signal in response to a reset of the controller 1 .

[0078] The first OR gate unit 223 is electrically connected to the detection unit 221 and the pull-down unit 222 , and is configured to output a fourth signal based on the second signal and the third signal.

[0079] The signal conversion unit 224 is electrically connected to the first OR gate unit 223 and is configured to convert the fourth signal into a fifth signal so that the driving circuit 3 controls the second switch Q2 to be turned off.

[0080] Exemplarily, the voltage of the first power source V1 is 5 V, and the voltage of the second power source V2 is 3.3 V. When the first switch Q1 is stuck, the second signal output by the detection unit 221 is at a low level.

[0081] Exemplarily, the voltage of the third power source V3 is 3.3V, and when the controller 1 is reset, the third signal output by the pull-down unit 222 is at a low level.

[0082] When the second signal and the third signal are at a low level, the fourth signal output by the first OR gate unit 223 is at a low level.

[0083] It is understandable that the second signal is used to indicate that the first switch is stuck, the third signal is used to indicate that the controller is reset, and the fourth signal is used to indicate that the first switch is stuck and the controller is reset.

[0084] Exemplarily, when the first switch is stuck and the controller is reset, the fifth signal output by the signal conversion unit 224 is a signal for enabling the driving circuit 3 , for example, the fifth signal is at a high level.

[0085] In this embodiment, by setting a detection unit, it is detected whether the first switch is stuck, by setting a pull-down unit, it is detected whether the controller is reset, by setting a first OR gate unit, the second switch is triggered to be disconnected only when the first switch is stuck and the controller is reset, and by setting a signal conversion unit, when the first switch is stuck and the controller is reset, an enable signal for controlling the operation of the drive circuit is output.

[0086] In some optional implementations, such as Figure 8 As shown, the second control circuit 22 further includes a second OR gate unit 225, and two input terminals of the second OR gate unit 225 are respectively electrically connected to the output terminal of the signal conversion unit 224 and the controller 1. The second OR gate unit 225 is configured to: in response to any one input terminal of the second OR gate unit 225 being at a high level, the second OR gate unit 225 outputs a high level, so that the driving circuit 3 controls the second switch to be disconnected.

[0087] When the controller 1 is working normally, if the second switch needs to be disconnected, the controller 1 outputs a high level. For example, when the controller 1 is working normally, it detects that the battery module is abnormal, and the abnormal conditions include: undervoltage, overvoltage, overtemperature, overcurrent, adhesion of the first switch, abnormal operation of certain circuits, or external input fault signals, etc. The controller 1 transmits a high level signal to the drive circuit 3 to disconnect the second switch Q2, thereby ensuring safety.

[0088] In this embodiment, not only when the first switch sticks and the controller is reset, the drive circuit is controlled to turn off the second switch, but also when the controller detects other abnormal conditions, the drive circuit is controlled to turn off the second switch, thereby achieving double protection and further improving safety.

[0089] In some optional implementations, such as Fig. 9 As shown, the detection unit 221 includes an electrical isolation element Q3, a first resistor R1, and a second resistor R2.

[0090] The input end of the electrical isolation element Q3, the first resistor R1 and the feedback contact of the first switch Q1 are connected in series between the first power supply V1 and the ground terminal GND, the output end of the electrical isolation element Q3 and the second resistor R2 are connected in series between the second power supply V2 and the ground terminal GND, and the second power supply V2 is electrically connected to the first input end of the first OR gate unit 223 through the second resistor R2.

[0091] In some embodiments, the electrical isolation element includes a photocoupler, a photorelay, or a photothyristor switch.

[0092] Exemplarily, the first switch Q1 includes coil contacts C1 and C2, feedback contacts A1 and A2, and connection contacts 1 and 2. Coil contacts C1 and C2 are used to access control signals, and connection contacts 1 and 2 are electrically connected to the charging path or the discharging path of the battery module. The state of whether the feedback contact A1 and the feedback contact A2 are connected follows the state of whether the connection contact 1 and the connection contact 2 are connected. That is, when the connection contact 1 and the connection contact 2 are connected, the feedback contact A1 and the feedback contact A2 are also connected. When the connection contact 1 and the connection contact 2 are disconnected, the feedback contact A1 and the feedback contact A2 are also disconnected. By detecting whether the feedback contact A1 and the feedback contact A2 are connected, it is possible to detect whether the first switch Q1 has a sticking fault.

[0093] The feedback contact A1 is electrically connected to the first power supply V1, the feedback contact A2 is electrically connected to the input end of the electrical isolation element Q3, the input end of the electrical isolation element Q3 is electrically connected to the ground end GND, and at least one first resistor R1 is connected in series on the path where the first power supply V1, the input end of the electrical isolation element Q3 and the ground end GND are located. For example, at least one first resistor R1 is connected in series between the feedback contact A1 and the first power supply V1, and at least one first resistor R1 is connected in series between the feedback contact A2 and the input end of the electrical isolation element Q3. It is understandable that the first resistor R1 is used for current limiting. In addition, the second resistor R2 is also used for current limiting.

[0094] When the feedback contact A1 and the feedback contact A2 are conducting, the input end of the electrical isolation element Q3 is electrically connected to the first power supply V1, the output end of the electrical isolation element Q3 is also conducting, and the second power supply V2 and the ground terminal GND are conducting, so that the potential of the first input end of the first OR gate unit 223 is pulled down by the ground terminal GND. That is, when the first switch Q1 is stuck, the second signal transmitted by the detection unit 221 to the first input end of the first OR gate unit 223 is at a low level.

[0095] When the feedback contact A1 is disconnected from the feedback contact A2, the input end of the electrical isolation element Q3 is disconnected from the first power supply V1, the output end of the electrical isolation element Q3 is disconnected, and the second power supply V2 is disconnected from the ground terminal GND, so that the potential of the first input end of the first OR gate unit 223 is pulled up by the second power supply V2. That is, when the first switch Q1 is turned off, the signal transmitted by the detection unit 221 to the first input end of the first OR gate unit 223 is a high level.

[0096] In this embodiment, the first detection unit includes an electrical isolation element and a first resistor and a second resistor. The first resistor and the second resistor are used to limit current to prevent devices in the circuit from being damaged by large currents. When the feedback contacts of the first switch are turned on or off, the electrical isolation element is in different states, thereby outputting different signals to detect whether the first switch is stuck.

[0097] In some other optional implementations, such as Fig.10 As shown, the detection unit 221 includes a first transistor T1, a third resistor R3, a fourth resistor R4 and a fifth resistor R5;

[0098] The third resistor R3 and the feedback contact of the first switch Q1 are connected in series between the control terminal of the first transistor T1 and the first power source V1 , and the fourth resistor R4 is electrically connected between the first terminal and the control terminal of the first transistor T1 .

[0099] A first end of the first transistor T1 is electrically connected to the ground terminal GND, a second end of the first transistor T1 is electrically connected to the second power source V2 via the fifth resistor R5 , and a second end of the first transistor T1 is electrically connected to the first OR gate unit 223 .

[0100] In some embodiments, the first transistor includes but is not limited to an N-type FET or an NPN transistor.

[0101] Exemplarily, the feedback contact A1 is electrically connected to the first power supply V1, and the feedback contact A2 is electrically connected to the control terminal of the first transistor T1. For example, at least one third resistor R3 is connected in series between the feedback contact A1 and the first power supply V1, and at least one third resistor R3 is connected in series between the feedback contact A2 and the control terminal of the first transistor T1. It is understandable that the third resistor R3 and the fifth resistor R5 are used for current limiting. The fourth resistor R4 serves as a bias resistor of the first transistor T1, so that the default state of the first transistor T1 is the off state.

[0102] When the feedback contact A1 and the feedback contact A2 are conducting, the control end of the first transistor T1 is electrically connected to the first power supply V1, the first transistor T1 is conducting, and the second power supply V2 and the ground terminal GND are conducting, so that the potential of the first input end of the first OR gate unit 223 is pulled down by the ground terminal GND. That is, when the first switch Q1 is stuck, the second signal transmitted by the detection unit 221 to the first input end of the first OR gate unit 223 is at a low level.

[0103] When the feedback contact A1 is disconnected from the feedback contact A2, the electrical connection between the control terminal of the first transistor T1 and the first power supply V1 is disconnected, the first transistor T1 is disconnected, and the electrical connection between the second power supply V2 and the ground terminal GND is disconnected, so that the potential of the first input terminal of the first OR gate unit 223 is pulled up by the second power supply V2. That is, when the first switch Q1 is turned off, the signal transmitted by the detection unit 221 to the first input terminal of the first OR gate unit 223 is a high level.

[0104] In this embodiment, the first detection unit includes a first transistor and a third resistor, a fourth resistor and a fifth resistor. The third resistor and the fifth resistor are used to limit current to prevent devices in the circuit from being damaged by large currents. When the feedback contacts of the first switch are turned on or off, the first transistor is in different states, so that the first detection unit outputs different signals to determine whether the first switch is stuck.

[0105] In some optional implementations, such as Fig. 9 or Fig.10 As shown, the signal conversion unit 224 includes a second transistor T2, a sixth resistor R6 and a seventh resistor R7. The control end of the second transistor T2 is electrically connected to the output end of the first OR gate unit 223 through the sixth resistor R6, the first end of the second transistor T2 is electrically connected to the third power supply V3, and the seventh resistor R7 is electrically connected between the first end of the second transistor and the control end thereof. The second end of the second transistor T2 is the output end of the signal conversion unit 224.

[0106] In some embodiments, the second transistor includes but is not limited to a P-type FET or a PNP-type transistor.

[0107] Exemplarily, the voltage of the third power supply V3 is 3.3V.

[0108] When the first OR gate unit 223 outputs a low level, the second transistor T2 is turned on, and the voltage of the third power supply V3 is output through the second transistor T2. That is, when the first OR gate unit 223 outputs a low level, the signal conversion unit 224 converts the low level output by the first OR gate unit 223 into a high level output. Here, the sixth resistor R6 is used for current limiting.

[0109] When the first OR gate unit 223 outputs a high level, the second transistor T2 is turned off, and the second end of the second transistor T2 does not output a signal.

[0110] It is understandable that, when both the detection unit 221 and the pull-down unit 222 output a low level, the first OR gate unit 223 outputs a low level, the second transistor T2 is turned on, and the signal conversion unit 224 outputs a high level. When either the detection unit 221 or the pull-down unit 222 outputs a high level, the first OR gate unit 223 outputs a high level, the second transistor T2 is turned off, and the signal conversion unit 224 does not output a signal.

[0111] The inventors further discovered that the feedback contact of the first switch may be mis-connected due to an interference signal, or, under normal circumstances, the first switch is controlled to be disconnected, but due to a signal delay, the detection unit detects that the first switch is still in the on state. These situations may cause errors in the detection of the state of the first switch.

[0112] In some optional implementations, such as Fig. 9 or Fig.10 As shown, the signal conversion unit 224 further includes a first capacitor C1, and the seventh resistor R7 and the first capacitor C1 are connected in parallel between the first end of the second transistor T2 and the control end thereof.

[0113] The sixth resistor R6 and the first capacitor C1 form a delay circuit of the second transistor T2. After the first OR gate unit 223 outputs a low-level signal and lasts for a certain period of time, the first capacitor C1 is fully charged, which will turn on the second transistor T2, thereby avoiding triggering the shutdown of the second switch due to false detection of the first switch sticking.

[0114] In some optional implementations, such as Fig. 9 or Fig.10 As shown, the pull-down unit 222 includes a third transistor T3, an eighth resistor R8 and a ninth resistor R9.

[0115] The control end of the third transistor T3 is electrically connected to the first control circuit 21, the eighth resistor R8 is electrically connected between the control end of the third transistor T3 and the ground end GND, the first end of the third transistor T3 is electrically connected to the ground end GND, and the second end of the third transistor T3 is electrically connected to the fourth power source V4 through the ninth resistor R9. In addition, the fourth power source V4 is electrically connected to the second input end of the first OR gate unit 223 through the ninth resistor R9.

[0116] In some embodiments, the third transistor includes an N-type FET or an NPN-type transistor.

[0117] Exemplarily, the voltage of the fourth power source V4 is 3.3V.

[0118] Exemplarily, when the controller is reset, the first control circuit 21 outputs a high level to the pull-down unit 222, the third transistor T3 is turned on, the fourth power supply V4 is electrically connected to the ground terminal GND through the third transistor T3, and the second end of the third transistor T3 outputs a low level to the second input end of the first OR gate unit 223.

[0119] Exemplarily, when the controller is operating normally, the first control circuit 21 outputs a low level to the pull-down unit 222, the third transistor T3 is turned off, the fourth electrical output V4 and the ground terminal GND are disconnected, and the voltage of the fourth power supply V4 is transmitted to the second input terminal of the first OR gate unit 223 through the ninth resistor R9.

[0120] It is understandable that the eighth resistor R8 is a bias resistor of the third transistor T3, so that the default state of the third transistor T3 is off. The ninth resistor R9 is a current limiting resistor.

[0121] In some optional implementations, such as Fig.11 or Fig.12 As shown, the switch control device includes a fifth power supply V5, and the first control circuit 21 includes a fourth transistor T4, a tenth resistor R10 and an eleventh resistor R11.

[0122] The eleventh resistor R11 is electrically connected between the control terminal of the fourth transistor T4 and the first terminal of the fourth transistor T4.

[0123] The control end of the fourth transistor T4 is electrically connected to the controller through the tenth resistor R10, the first end of the fourth transistor T4 is electrically connected to the fifth power supply V5, and the second end of the fourth transistor T4 is electrically connected to the second control circuit. Specifically, the second end of the fourth transistor T4 is electrically connected to the pull-down unit 222.

[0124] In some embodiments, the fourth transistor T4 includes but is not limited to a P-type FET or a PNP-type transistor.

[0125] When the controller 1 is reset, the controller 1 sends a low level to the control terminal of the fourth transistor T4 through the tenth resistor R10, the fourth transistor T4 is turned on, and the voltage of the fifth power source V5 is transmitted to the pull-down unit through the fourth transistor T4.

[0126] Exemplarily, the voltage of the fifth power supply V5 is 3.3V.

[0127] The tenth resistor R10 is a current limiting resistor. The eleventh resistor R11 is a bias resistor of the fourth transistor T4, so that the default state of the fourth transistor T4 is an off state.

[0128] In some embodiments, Fig.11 or Fig.12As shown, the controller 1 is electrically connected to the second input terminal of the second OR gate unit 225 through the twelfth resistor R12, and the twelfth resistor R12 is used for current limiting.

[0129] For example, Fig.13 As shown, the driving circuit 3 includes a fifth transistor T5, the control end of the fifth transistor T5 is electrically connected to the first enable pin EN1 of the driving circuit 3, and the first enable pin EN1 is electrically connected to the output end of the second control circuit 22. The first end of the fifth transistor T5 is electrically connected to the sixth power supply V6, and a second capacitor C2 is connected between the sixth power supply V6 and the ground terminal GND. The second end of the fifth transistor T5 is electrically connected to the second switch Q2. For example, the voltage of the sixth power supply V6 is 12V, and the second switch Q2 is a circuit breaker. When the fifth transistor T5 is turned on, the voltage of 12V is transmitted to the control end of the circuit breaker, and the circuit breaker is turned off.

[0130] The fifth transistor T5 includes but is not limited to an N-type FET or an NPN-type triode.

[0131] Below Fig.13 Take this as an example to introduce the working principle of the switch drive device:

[0132] When a sticking fault occurs in the first switch Q1, the feedback contact A1 and the feedback contact A2 of the first switch Q1 are connected, so that the first power supply V1 is electrically connected to the input end of the electrical isolation element Q3, and then the output end of the electrical isolation element Q3 connects the second power supply V2 and the ground end GND, and the first input end of the first OR gate unit 223 is connected to a low level.

[0133] When the controller 1 is reset, the controller 1 transmits a low level to the fourth transistor T4, the fourth transistor T4 is turned on, the voltage of the fifth power supply V5 is transmitted to the control end of the third transistor T3, the third transistor T3 is turned on, and the second input end of the first OR gate unit 223 is connected to the low level.

[0134] When both input terminals of the first OR gate unit 223 are connected to a low level, the output terminal of the first OR gate unit 223 outputs a low level to the signal conversion unit 224 .

[0135] The signal conversion unit 224 includes a delay circuit composed of a sixth resistor R6 and a first capacitor C1. After the output terminal of the first OR gate unit 223 outputs a low level for a certain period of time, the second transistor T2 is turned on, and the first input terminal of the second OR gate unit 225 receives a high level signal.

[0136] When a high level signal is connected to the first input terminal of the second OR gate unit 225, the output terminal of the second OR gate unit 225 outputs a high level signal, the fifth transistor T5 is turned on, and the voltage of the sixth power supply V6 is transmitted to the second switch Q2 to turn off the second switch Q2.

[0137] When the controller 1 is working normally, when an abnormality occurs in the battery module, the controller 1 transmits a high level to the second input terminal of the second OR gate unit 225. In this case, the output terminal of the second OR gate unit 225 also outputs a high level, the fifth transistor T5 is turned on, and the voltage of the sixth power supply V6 is transmitted to the second switch Q2 to disconnect the second switch Q2.

[0138] It should be noted that in the embodiments shown in the above figures, the resistor is represented by a single resistor, and the capacitor is represented by a single capacitor. In other embodiments, the resistor may be an integration of series, parallel or mixed resistors, and the capacitor may be an integration of series, parallel or mixed capacitors. The specific parameters of each device can be set according to actual needs, and this application does not limit this.

[0139] According to the embodiments described above in the present application, these embodiments do not describe all the details in detail, nor do they limit the present application to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and the modifications based on the present application. The present application is limited only by the claims and their full scope and equivalents.

Claims

1. A switch control device, comprising a first switch, a second switch, a controller, a control circuit and a drive circuit, characterized in that: The control circuit is electrically connected to the first switch, the drive circuit and the controller respectively, and the drive circuit is electrically connected to the first switch and the second switch respectively; The control circuit is configured to transmit a control signal to the drive circuit to turn off the second switch in response to the controller being reset and the first switch being stuck.

2. The switch control device according to claim 1, characterized in that: The control circuit includes a first control circuit and a second control circuit electrically connected to the first control circuit; The first control circuit is electrically connected to the controller, and the second control circuit is electrically connected to the second switch through the drive circuit; The first control circuit is configured to transmit a first signal to the second control circuit in response to a reset of the controller; The second control circuit is configured to detect a state of the first switch, and in response to the first switch being stuck and the second control circuit receiving the first signal, the second control circuit transmits a control signal to the drive circuit to turn off the second switch.

3. The switch control device according to claim 2, characterized in that: The switch control device includes a first power supply and a second power supply, and the second control circuit includes a detection unit, a pull-down unit, a first OR gate unit and a signal conversion unit; The detection unit is electrically connected to the first switch and the first power supply and the second power supply, and the detection unit is configured to: output a second signal in response to the first switch being stuck; The pull-down unit is electrically connected to the third power source and the controller, and is configured to: output a third signal in response to the controller being reset; The first OR gate unit is electrically connected to the detection unit and the pull-down unit, and is configured to: output a fourth signal based on the second signal and the third signal; The signal conversion unit is electrically connected to the first OR gate unit and is configured to convert the fourth signal into a fifth signal so that the driving circuit controls the second switch to be turned off.

4. The switch control device according to claim 3, characterized in that: The second control circuit also includes a second OR gate unit; The two input ends of the second OR gate unit are electrically connected to the output end of the signal conversion unit and the controller respectively; The second OR gate unit is configured to: in response to any one input terminal of the second OR gate unit being at a high level, the second OR gate unit outputs a high level, so that the driving circuit controls the second switch to be turned off.

5. The switch control device according to claim 3 or 4, characterized in that: The detection unit includes an electrical isolation element, a first resistor, and a second resistor; The input end of the electrical isolation element, the first resistor and the feedback contact of the first switch are connected in series between the first power supply and the ground end, and the output end of the electrical isolation element and the second resistor are connected in series between the second power supply and the ground end; The second power supply is electrically connected to the first OR gate unit through the second resistor; or, The detection unit includes a first transistor, a third resistor, a fourth resistor and a fifth resistor; The third resistor and the feedback contact of the first switch are connected in series between the control terminal of the first transistor and the first power supply, and the fourth resistor is electrically connected between the first terminal and the control terminal of the first transistor; The first end of the first transistor is electrically connected to the ground end, the second end of the first transistor is electrically connected to the second power supply through the fifth resistor, and the second end of the first transistor is electrically connected to the first OR gate unit.

6. The switch control device according to claim 5, characterized in that: The electrical isolation element includes a photocoupler, a photorelay or a photo-thyristor; or, The first transistor includes an N-type FET or an NPN transistor.

7. The switch control device according to any one of claims 3 to 6, characterized in that: The signal conversion unit includes a second transistor, a sixth resistor and a seventh resistor; The control end of the second transistor is electrically connected to the output end of the first OR gate unit through the sixth resistor, the first end of the second transistor is electrically connected to the third power supply, and the second end of the second transistor is the output end of the signal conversion unit; The seventh resistor is disposed between the first end of the second transistor and the control end thereof, and the third power supply is electrically connected to the output end of the signal conversion unit through the sixth resistor and the seventh resistor.

8. The switch control device according to claim 7, characterized in that: The signal conversion unit further includes a first capacitor; The seventh resistor is connected in parallel with the first capacitor, the second transistor, the first end of the first capacitor, the first end of the sixth resistor and the first end of the seventh resistor are electrically connected to a first node, the second end of the sixth resistor is electrically connected to the output end of the first OR gate unit, and the first end of the second transistor, the second end of the first capacitor and the second end of the seventh resistor are all electrically connected to the third power supply.

9. The switch control device according to claim 7 or 8, characterized in that: The second transistor includes a P-type FET or a PNP-type triode.

10. The switch control device according to any one of claims 3 to 9, characterized in that: The pull-down unit includes a third transistor, an eighth resistor and a ninth resistor; The control end of the third transistor is electrically connected to the first control circuit, the eighth resistor is electrically connected between the control end and the ground end of the third transistor, the first end of the third transistor is electrically connected to the ground end, the second end of the third transistor is electrically connected to the fourth power supply through the ninth resistor, and the fourth power supply is electrically connected to the input end of the first OR gate unit through the ninth resistor.

11. The switch control device according to claim 10, characterized in that: The third transistor includes an N-type FET or an NPN-type triode.

12. The switch control device according to any one of claims 2 to 11, characterized in that: The switch control device includes a fifth power supply; The first control circuit includes a fourth transistor, a tenth resistor and an eleventh resistor; The control end of the fourth transistor is electrically connected to the controller through the tenth resistor, the first end of the fourth transistor is electrically connected to the fifth power supply, and the second end of the fourth transistor is electrically connected to the second control circuit; The eleventh resistor is electrically connected between the control terminal of the fourth transistor and the first terminal of the fourth transistor.

13. A battery management system, characterized in that: The invention comprises a switch control device as claimed in any one of claims 1 to 12.

14. A battery pack, characterized in that: include: Battery module; And the battery management system as claimed in claim 13.

15. An electrical device, characterized in that: A battery pack comprising the battery pack of claim 14.

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