Short circuit protection circuit, power battery pack and vehicle

Abstract

The application discloses a short-circuit protection circuit, a power battery pack and a vehicle. The short-circuit protection circuit comprises a first driving module, a detection circuit and a fuse circuit. The fuse circuit is connected in series between a first connection end and a second connection end. The detection circuit is connected in parallel to the two ends of the fuse circuit. The short-circuit protection circuit comprises a response device and a circuit breaker. The circuit breaker is connected in series between the first connection end and the second connection end. The response device is connected to the detection circuit and the circuit breaker. A circuit breaker detection module is connected to the detection circuit. A control module is connected to the circuit breaker detection module and is configured to obtain the port voltage of the first detection port and the second detection port, and determine whether the detection circuit is in a circuit breaking state based on the port voltage. The short-circuit protection circuit has a circuit breaking detection function, which can prevent the fuse circuit from being unable to trigger the circuit breaker to cut off the external load circuit after the fuse circuit is fused in the case that the line between the fuse circuit and the response device is broken.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a short-circuit protection circuit, a power battery pack, and a vehicle. Background Technology

[0002] With the continuous development of lithium battery technology, the charging power of power batteries in new energy vehicles is gradually increasing, but this also increases the risk of thermal runaway of power batteries.

[0003] To ensure the safe use of power batteries, short-circuit protection schemes for power battery systems are increasingly trending towards replacing traditional thermal fuses connected in series in the main circuit of the power battery with circuit breakers (e.g., pyrotechnic circuit breakers). A circuit breaker is a device that is activated by an external driver to ignite and thus disconnect the main circuit of the power battery. Compared to traditional thermal fuses, circuit breakers do not produce an electric arc after disconnecting the circuit, thus preventing damage to external equipment from the arc.

[0004] However, the scheme of controlling the circuit breaker through an external driver places extremely high demands on the short-circuit current judgment capability, software diagnostic decision-making capability, and system reliability of the external controller. Once the external driver fails, in the event of a power battery failure, the external driver cannot promptly control the circuit breaker to disconnect the branch between the power battery and the external equipment, resulting in irreparable damage to the external equipment. Summary of the Invention

[0005] This application provides a short-circuit protection circuit, a power battery pack, and a vehicle.

[0006] Some embodiments of this application provide a short-circuit protection circuit, wherein the short-circuit protection circuit has a first connection terminal and a second connection terminal for connecting an external load circuit, and the short-circuit protection circuit includes a first driving module, a circuit breaking module, a circuit breaking detection module, and a control module. The first driving module includes a fuse circuit and a detection circuit. The fuse circuit is connected in series between the first and second connection terminals. The detection circuit is connected in parallel across the fuse circuit to acquire the detection voltage across the fuse circuit. The circuit breaking module includes a responder and a circuit breaker. The circuit breaker and the fuse circuit are connected in series between the first and second connection terminals. The responder is connected to the detection circuit and to the circuit breaker. The responder is used to trigger the circuit breaker to disconnect the circuit between the first and second connection terminals when the detection voltage is greater than a specified voltage. The circuit breaking detection module has a first detection port and a second detection port, which are connected in parallel across the detection circuit. The control module is connected to the circuit breaking detection module and configured to: acquire the port voltages of the first and second detection ports, and determine whether the detection circuit is in an open-circuit state based on the port voltages.

[0007] Some embodiments of this application also provide a power battery pack, which includes a battery pack and the aforementioned short-circuit protection circuit, wherein the first connection terminal and the second connection terminal of the short-circuit protection circuit are respectively connected to the positive and negative terminals of the battery pack.

[0008] Some embodiments of this application also provide a vehicle, the vehicle including: a housing and the aforementioned power battery pack, wherein the power battery pack is disposed within the housing.

[0009] This application discloses a short-circuit protection circuit, a power battery pack, and a vehicle. The short-circuit protection circuit is connected to an external load circuit via a first connection terminal and a second connection terminal. A fuse and a circuit breaker are connected in series between the first and second connection terminals, and the circuit breaker is connected to a responder. In this application, the responder is connected to a detection circuit connected in parallel across the fuse. When the fuse is in a blown state, the detected voltage across the fuse is greater than a specified voltage. At this time, the responder triggers the circuit breaker to disconnect the circuit between the first and second connection terminals. Therefore, in the event of a short circuit in the external load circuit, the fuse blows, triggering the circuit breaker to disconnect the external load circuit. That is, the circuit breaker module can quickly disconnect the external load circuit without connecting an external driver, saving hardware costs.

[0010] Furthermore, the short-circuit protection circuit in this application also includes an open-circuit detection module and a control module. The open-circuit detection module is connected in parallel across the two ends of the detection circuit. The control module is connected to the open-circuit detection module and determines whether the detection circuit is in an open-circuit state based on the port voltage obtained by the open-circuit detection module, that is, whether an open circuit has occurred in the line between the fuse circuit and the responder. Therefore, the short-circuit protection circuit in this application also has an open-circuit detection function, avoiding the situation where the fuse circuit fails to trigger the circuit breaker to cut off the external load circuit after blowing when an open circuit occurs in the line between the fuse circuit and the responder, thus ensuring the reliability of the connection between the fuse circuit and the responder. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the application environment of the short-circuit protection circuit provided in this application.

[0013] Figure 2 yes Figure 1 The diagram shows a structural schematic of a first possible implementation of the short-circuit protection circuit.

[0014] Figure 3 yes Figure 1 The diagram shows a second possible implementation of the short-circuit protection circuit.

[0015] Figure 4 This is a schematic diagram of the circuit breaker detection module provided in this application.

[0016] Figure 5 yes Figure 1 The diagram shows a third possible implementation of the short-circuit protection circuit.

[0017] Figure 6 yes Figure 1 The diagram shows a fourth possible implementation of the short-circuit protection circuit.

[0018] Figure 7 This is a schematic diagram of the structure of the suppression unit provided in this application. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0020] Please see Figure 1 This application provides a short-circuit protection circuit 100 and a vehicle 200 equipped with the short-circuit protection circuit 100. The vehicle 200 includes a housing 210 and a power battery pack 230, which is disposed within the housing 210 and provides kinetic energy to the vehicle 200. Taking a new energy vehicle as an example, the power battery pack 230 provides driving force to the new energy vehicle and, through the transmission system, drives the driving system (e.g., axles and wheels) to operate.

[0021] The power battery pack 230 in this embodiment includes a battery group 2310 and the aforementioned short-circuit protection circuit 100. The short-circuit protection circuit 100 has a first connection terminal 10 and a second connection terminal 20 for connecting the battery group 2310. In this embodiment, the battery group 2310 serves as an external load circuit for the short-circuit protection circuit 100. The short-circuit protection circuit 100 provides short-circuit protection for this external load circuit (i.e., the battery group 2310) to improve the safety performance of the power battery pack 230. Specifically, the first connection terminal 10 and the second connection terminal 20 of the short-circuit protection circuit 100 can be connected to the positive and negative terminals of the battery group 2310, respectively. In the event of a short circuit in the battery group 2310, the circuit between the first connection terminal 10 and the second connection terminal 20 is disconnected, preventing the battery group 2310 from experiencing short-circuit runaway and causing damage to external power supply equipment. Specifically, the battery group 2310 may include multiple battery cells, which may be lithium battery cells, nickel-metal hydride battery cells, etc. It should be noted that the application environment of the short-circuit protection circuit 100 provided in this application is only illustrative. The short-circuit protection circuit 100 can also be applied to other vehicles, electrical equipment, electrical control systems, etc. that have high-voltage circuits. This application does not impose any specific limitations.

[0022] Please see Figure 2 The short-circuit protection circuit 100 in this embodiment includes a first driving module 30, a circuit breaking module 50, a circuit breaking detection module 70, and a control module 90. The first driving module 30 is connected to the circuit breaking module 50. A portion of the first driving module 30 is connected to both ends of an external load circuit (such as a battery pack 2310) via a first connection terminal 10 and a second connection terminal 20. A portion of the circuit breaking module 50 is connected to the circuit between the first connection terminal 10 and the second connection terminal 20. In the event of a short circuit in the external load circuit (such as the battery pack 2310), the first driving module 30 can control the circuit breaking module 50 to disconnect the circuit between the first connection terminal 10 and the second connection terminal 20. Therefore, controlling the circuit breaking module 50 can achieve rapid circuit disconnection without connecting an external driver, saving hardware costs. The circuit breaker detection module 70 is connected to the first drive module 30, and the control module 90 is connected to the circuit breaker detection module 70. Based on the voltage signal detected by the circuit breaker detection module 70, the control module 90 determines whether a circuit breaker has occurred between the first drive module 30 and the circuit breaker module 50, thus ensuring the reliability of the connection between the first drive module 30 and the circuit breaker module 50.

[0023] The following is a detailed description of each module in the short-circuit protection circuit 100.

[0024] Please see Figure 3The first driving module 30 includes a fuse circuit 320 and a detection circuit 340. The fuse circuit 320 is connected in series between the first connection terminal 10 and the second connection terminal 20; that is, the fuse circuit 320 is connected in series in the branch containing the external load circuit. When a short circuit occurs in the external load circuit, the current in the branch exceeds a predetermined value, causing the fuse circuit 320 to blow. Specifically, the fuse circuit 320 can be a thermal fuse (e.g., a thermal fuse wire). The detection circuit 340 is connected in parallel across the fuse circuit 320 to obtain the detection voltage across the fuse circuit 320.

[0025] The circuit breaker module 50 includes a responder 520 and a circuit breaker 540, with the responder 520 connected to the detection circuit 340. Specifically, the responder 520 and the fuse circuit 320 are connected in parallel, meaning the voltage across the responder 520 is equal to the detection voltage. When the fuse circuit 320 is in a normal state, the detection voltage is less than or equal to a specified voltage, and the responder 520 is also in a normal state. When the fuse circuit 320 is in a blown state, the detection voltage is greater than the specified voltage, the responder 520 is in a triggered state, thereby controlling the circuit breaker 540 connected to the responder 520 to operate. In some embodiments, the circuit breaker module 50 is a pyrotechnic circuit breaker, and the responder 520 is the ignition bridge wire in the pyrotechnic circuit breaker. When the ignition bridge wire is in a triggered state, the ignition bridge wire ignites, thereby triggering the circuit breaker 540 to operate.

[0026] Circuit breaker 540 and fuse circuit 320 are connected in series between first connection terminal 10 and second connection terminal 20, and are also connected to responder 520. When responder 520 triggers circuit breaker 540 to operate, circuit breaker 540 disconnects the circuit between first connection terminal 10 and second connection terminal 20. Specifically, in the case where circuit breaker module 50 is a pyrotechnic circuit breaker, circuit breaker 540 is a knife switch.

[0027] In this embodiment, a detection loop is formed between the responder 520 and the fuse 320. When the fuse 320 is in a blown state, the detected voltage across the fuse 320 is greater than a specified voltage. At this time, the responder 520 triggers the circuit breaker 540 to disconnect the circuit between the first connection terminal 10 and the second connection terminal 20. That is, in the event of a short circuit in the external load circuit, the fuse 320 blows, thereby triggering the circuit breaker 540 to disconnect the external load circuit. Therefore, the circuit breaker module 50 can quickly disconnect the external load circuit without connecting an external driver, saving hardware costs.

[0028] The circuit breaker detection module 70 has a first detection port 710 and a second detection port 720, which are connected in parallel across the detection circuit 340. These ports are used to detect the port voltages of the first and second detection ports 710 and to send these port voltages to a control module 90 connected to the circuit breaker detection module 70. The control module 90 is configured to acquire the port voltages of the first and second detection ports 710 and, based on these port voltages, determine whether the detection circuit 340 is in an open-circuit state. Specifically, the implementation method of the control module 90 determining whether the detection circuit 340 is in an open-circuit state based on the port voltages is described in the following embodiments. Therefore, the short-circuit protection circuit 100 in this application also has a circuit breaker detection function, preventing the situation where, in the event of an open circuit between the fuse circuit 320 and the responder 520, the fuse circuit 320 blows but fails to trigger the circuit breaker 540 to disconnect the external load circuit, thus ensuring the reliability of the connection between the fuse circuit 320 and the responder 520.

[0029] Please see Figure 4 The circuit breaker detection module 70 includes a power supply submodule 730, a switch submodule 740, and a voltage detection submodule 750. The voltage detection submodule 750 is connected in parallel across the first detection port 710 and the second detection port 720 to detect the port voltages of both ports. The voltage detection submodule 750 is also connected to the control module 90 to transmit the detected port voltages. Specifically, the voltage detection submodule 750 can be a voltage detection device such as a Hall effect voltage sensor or a fiber optic voltage sensor.

[0030] The switch submodule 740 is connected between the voltage detection submodule 750 and the power supply submodule 730. When the switch submodule 740 is in the ON state, the power supply submodule 730 discharges to the detection circuit 340, at which time the voltage detection submodule 750 detects the port voltage. The switch submodule 740 is connected to the control module 90, that is, the control module 90 controls the switch submodule 740 to enter the ON state. Therefore, the control module 90 is also configured to: send a trigger signal to the switch submodule 740 to trigger the switch submodule 740 to enter the ON state; and, when the switch submodule 740 is in the ON state, acquire the port voltages of the first detection port 710 and the second detection port 720.

[0031] In some embodiments, the switching submodule 740 may include multiple resistors and transistors. Figure 4 In the embodiment shown, the switch submodule 740 includes a first transistor Q1, a second transistor Q2, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4.

[0032] The first transistor Q1 is a PNP transistor. The emitter of Q1 is connected to the power supply submodule 730 via a first resistor R1. The collector of Q1 is connected to the first detection port 710. The base of Q1 is connected to the collector of the second transistor Q2 via a third resistor R3. The second transistor Q2 is an NPN transistor. The emitter of Q2 is connected to the second detection port 720 and grounded. The base of Q2 is connected to the control module 90 via a fourth resistor R4. One end of the second resistor R2 is connected to the common connection terminal of the first resistor R1 and the emitter of the first transistor Q1; the other end is connected to the common connection terminal of the base of the first transistor Q1 and the third resistor R3.

[0033] The first resistor R1 is a current-limiting resistor, used to limit the current output from the power supply submodule 730 to the detection circuit 340 when the switching submodule 740 is in the on state. The second resistor R2 is a voltage divider resistor, connected in parallel between the emitter and base of the first transistor Q1, used to ensure that the first transistor Q1 has a sufficient turn-on voltage. The third resistor R3 is a collector protection resistor, used to prevent a short circuit in the detection circuit 340 when the first transistor Q1 and the second transistor Q2 are in the on state. The fourth resistor R4 is a base current-limiting resistor, used to prevent excessive base current from burning out the second transistor Q2.

[0034] Here is the Figure 4 The working process of the switch submodule 740 shown is described below.

[0035] The control module 90 outputs a high-level signal to the second transistor Q2 through the fourth resistor R4, turning on the second transistor Q2. A closed loop is formed between the first resistor R1, the second resistor R2, the third resistor R3, and the second transistor Q2. In this situation, the voltage across the second resistor R2 is greater than the turn-on voltage of the first transistor Q1, turning on the first transistor Q1. The power supply submodule 730 discharges to the detection circuit 340 through the first resistor R1 and the first transistor Q1, at which point the switch submodule 740 is in the on state.

[0036] The control module 90 outputs a low-level signal to the second transistor Q2 through the fourth resistor R4. The second transistor Q2 enters the cutoff state, and the first transistor Q1 enters the cutoff state. At this time, the switch submodule 740 is in the off state.

[0037] Therefore, the control module 90 can control the switching submodule 740 by outputting signals of different levels. It should be noted that the high-level and low-level signals output by the control module 90 are determined based on the turn-on voltage of the second transistor Q2. Taking a silicon transistor Q2 as an example, with a turn-on voltage of 0.7V, the amplitude of the high-level signal can be greater than or equal to 0.7V, for example, a high-level signal amplitude of 1V; the amplitude of the low-level signal can be less than 0.7V, for example, a low-level signal amplitude of 0V.

[0038] In some embodiments, the first resistor R1 has a resistance of 5Ω, the second resistor R2 has a resistance of 10kΩ, the third resistor R3 has a resistance of 1kΩ, the fourth resistor R4 has a resistance of 1kΩ, and the output voltage of the power supply submodule 730 is 5V. When the second transistor Q2 is in the conducting state, the voltage across the second resistor R2 is 4.54V, which is much higher than the turn-on voltage of the first transistor Q1. At this time, the first transistor Q1 is in the conducting state. In some embodiments, the first transistor Q1 is a silicon transistor, and the corresponding turn-on voltage is 0.7V. In some embodiments, the first transistor Q1 is a germanium transistor, and the corresponding turn-on voltage is 0.3V.

[0039] It should be noted here that... Figure 4 The circuit structure of the switch submodule 740 shown is only illustrative. The first transistor Q1 and the second transistor Q2 can be replaced with other power electronic devices with switching functions, such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), etc. This embodiment does not impose specific limitations.

[0040] In some embodiments, the switch submodule 740 can also be a relay switch. The relay switch includes a switch module and a control module. The switch module is connected between the voltage detection submodule 750 and the power supply submodule 730, and is electrically connected to the control module. The control module is connected to the control module 90. When the control module 90 outputs a trigger signal to the control module, the control module controls the switch module to close. Specifically, the relay switch can be an electromagnetic relay, an inductive relay, an electric relay, an electronic relay, etc., and this embodiment does not impose specific limitations.

[0041] The power supply submodule 730 includes a voltage power supply 7310, a fifth resistor R5, and a capacitor C0. The voltage power supply 7310 is a DC voltage power supply; specifically, the voltage amplitude of the power supply can be 5V. The fifth resistor R5 is connected in series between the voltage power supply 7310 and the first resistor R1. One end of the capacitor C0 is connected to the common connection terminal of the first resistor R1 and the fifth resistor R5, and the other end is grounded. Therefore, when the voltage power supply 7310 is powered on, the capacitor C0 is charged through the fifth resistor R5. Specifically, with a resistance of 10kΩ for the fifth resistor R5 and a capacitance of 100uF for the capacitor C0, the capacitor C0 can complete charging within 12.5ms. Subsequently, when the switch submodule 740 is in the ON state, the capacitor C0 discharges into the detection circuit 340. This embodiment does not limit the specific type of capacitor C0. Figure 4 In the embodiment shown, capacitor C0 is an electrolytic capacitor with a capacitance of 100uF.

[0042] Please refer to it again. Figure 3 In some embodiments, the detection circuit 340 includes an isolation transformer unit 3420, the primary side of which is electrically connected to both ends of the fuse circuit 320. The secondary side of the isolation transformer unit 3420 is electrically connected to both ends of the responder 520 and is connected in parallel with the first detection port 710 and the second detection port 720. The isolation transformer unit 3420 is used to improve the anti-interference performance of the circuit breaker detection module 70, that is, to suppress electromagnetic interference in the short-circuit protection circuit 100. In addition, the external load circuit is usually a high-voltage circuit, while the circuit breaker detection module 70 is a low-voltage circuit. Connecting the isolation transformer unit 3420 between the external load circuit and the circuit breaker detection module 70 can achieve the effect of high and low voltage isolation, ensuring the safe use of the circuit breaker detection module 70. Specifically, the isolation transformer unit 3420 can be an isolation transformer. This application embodiment does not limit the model and hardware parameters of the isolation transformer.

[0043] Here we combine Figure 3 and Figure 4 The specific implementation method of the control module 90 determining whether the detection circuit 340 is in an open-circuit state based on port voltage is described. As one implementation, the control module 90 stores a fault mapping table, which represents the mapping relationship between the port voltage value and whether the detection circuit 340 is in an open-circuit state. When the control module 90 obtains the port voltage, it can determine whether the detection circuit 340 is in an open-circuit state by looking up the fault mapping table.

[0044] Specifically, when the detection circuit 340 is not in an open-circuit state, the connection between the fuse circuit 320 and the primary side of the isolation transformer unit 3420 is normal. Taking the fuse circuit 320 as an example, the resistance of the fuse is about 10uΩ. At this time, the primary side of the isolation transformer unit 3420 is equivalent to a short circuit, resulting in a low secondary impedance of the isolation transformer unit 3420. Specifically, the secondary impedance is approximately equal to 1Ω, that is, the equivalent resistance of the detection circuit 340 is 1Ω. At this time, the capacitor C0 discharges into the detection circuit 340. With the resistance of the first resistor R1 being 5Ω and ignoring the voltage drop of the first transistor Q1, the port voltage detected by the voltage detection submodule 750 is approximately 0.83V.

[0045] When the detection circuit 340 is in an open-circuit state, the connection between the fuse circuit 320 and the primary side of the isolation transformer unit 3420 is open, resulting in a large secondary impedance of the isolation transformer unit 3420. Specifically, the secondary impedance is approximately 50Ω, that is, the equivalent resistance of the detection circuit 340 is 50Ω. At this time, the capacitor C0 discharges into the detection circuit 340. Similarly, with the resistance of the first resistor R1 being 5Ω and the voltage drop of the first transistor Q1 being ignored, the port voltage detected by the voltage detection submodule 750 is approximately 4.5V.

[0046] Therefore, the control module 90 can determine whether the detection circuit 340 is in an open-circuit state by the magnitude of the port voltage. Specifically, the control module 90 may have a control chip, integrated circuit board, or other structures, which are not specifically limited in this embodiment. In some embodiments, the short-circuit protection circuit 100 further includes an alarm module (not shown in the figure), which is electrically connected to the control module 90 and is used to issue an alarm signal when the detection circuit 340 is in an open-circuit state. The alarm module may be an indicator light, speaker, or other similar device, which are not specifically limited in this application. In some embodiments, the short-circuit protection circuit 100 further includes a communication module (not shown in the figure), which is electrically connected to the control module 90 and communicates with an external communication device (e.g., a mobile terminal, a vehicle center console), and is used to issue a notification message when the detection circuit 340 is in an open-circuit state. The control module 90 is also configured to send an alarm command if the detection circuit is in an open-circuit state.

[0047] In some embodiments, please refer to Figure 5The short-circuit protection circuit 100 also includes a second drive module 40. The second drive module 40 is electrically connected to the responder 520 and can be a drive control chip, integrated circuit board, or similar structure. On one hand, the second drive module 40 is electrically connected to a signal detection device (e.g., a voltage detection device) in the external load circuit to acquire the detection signal sent by the signal detection device. On the other hand, the second drive module 40 is used to send a trigger current to the responder 520 when the detection signal is abnormal, i.e., when a short circuit is determined to have occurred in the external load circuit based on the detection signal. The trigger current refers to the current that enables the responder 520 to enter a triggered state; that is, the trigger current generated by the second drive module 40 triggers the circuit breaker 540 through the responder 520 to disconnect the circuit between the first connection terminal 10 and the second connection terminal 20. Specifically, the magnitude of the trigger current is determined by the specific model of the circuit breaker module 50; for example, the trigger current is 1.75A. Therefore, the short-circuit protection circuit 100 in this embodiment is provided with dual protection measures (i.e., fuse circuit protection and second drive module protection), making the short-circuit protection safer and more reliable. Even if the second drive module 40 fails, the external load circuit can be cut off by triggering the responder 520 through the fuse short circuit 320, thus preventing the external load circuit from being damaged due to short circuit and loss of control.

[0048] In some embodiments, the second driving module 40 is provided with a first output terminal 410 and a second output terminal 420, and the second driving module 40 is electrically connected to the responder 520 through the first output terminal 410 and the second output terminal 420. In this embodiment, the short-circuit protection circuit 100 further includes a first filter capacitor C1 and a second filter capacitor C2, wherein the first output terminal 7410 is grounded through the first filter capacitor C1, and the second output terminal 7420 is grounded through the second filter capacitor C2. The first filter capacitor C1 and the second filter capacitor C2 improve the stability of the second driving module 40 during operation.

[0049] In some embodiments, the short-circuit protection circuit 100 further includes a first connector 60 and a second connector 80, wherein the open-circuit detection module 70 is connected to the responder 520 via the first connector 60, and the second connector 80 is connected to the responder 520 via the second connector 80. See also... Figure 6 The first connector 60 can be a twisted-pair cable harness, with one end connected in parallel to both ends of the responder 520, and the other end connected to the first detection port 710 and the second detection port 720 of the circuit breaker detection module 70, respectively. Each twisted wire in the twisted-pair cable harness can be considered as a series connection of inductance and resistance. Specifically, in Figure 6In the illustrated embodiment, one end of the series connection between the first line inductor L1 and the sixth line resistor R6 is connected to one end of the responder 520, and the other end is connected to the first detection port 710. Similarly, one end of the series connection between the second line inductor L2 and the seventh line resistor R7 is connected to the other end of the responder 520, and the other end is connected to the second detection port 720. In this embodiment, the first connector 60 is detachably connected to both the responder 520 and the open circuit detection module 70. Therefore, when either the first connector 60 or the open circuit detection module 70 malfunctions, maintenance personnel can easily disassemble, repair, and replace them.

[0050] In some embodiments, the length of the first connector 60 is greater than or equal to 4 meters. Therefore, the circuit breaker detection module 70 and the detection circuit 340 located at both ends of the first connector 60 can be respectively set at different positions in the power battery pack 230, making the overall circuit layout of the short circuit protection circuit 100 more flexible.

[0051] Similarly, the second connector 80 can be a twisted-pair cable harness, with one end connected in parallel to both ends of the responder 520, and the other end connected to the first output terminal 410 and the second output terminal 420 of the second drive module 40, respectively. Each twisted wire in the twisted-pair cable harness can be considered as a series connection of inductance and resistance. Specifically, in Figure 6 In the illustrated embodiment, one end of the series connection between the third line inductor L3 and the eighth line resistor R8 is connected to one end of the responder 520, and the other end is connected to the first output terminal 410. Similarly, one end of the series connection between the fourth line inductor L4 and the ninth line resistor R9 is connected to the other end of the responder 520, and the other end is connected to the second output terminal 420. In this embodiment, the second connector 80 is detachably connected to the responder 520 and the second drive module 40, respectively. Therefore, when the second connector 80 or the second drive module 40 fails, maintenance personnel can easily disassemble, repair, and replace the second connector 80 and the second drive module 40.

[0052] In some embodiments, the length of the second connector 80 is greater than or equal to 4 meters. Therefore, the circuit breaker detection module 70 and the detection circuit 340 located at both ends of the second connector 80 can be respectively set at different positions in the power battery pack 230, making the overall circuit layout of the short circuit protection circuit 100 more flexible.

[0053] In some embodiments, the detection circuit 340 further includes a rectifier unit 3440. The input terminal of the rectifier unit 3440 is connected to both ends of the fuse circuit 320 via an isolation transformer unit 3420, and the output terminal of the rectifier unit 3440 is connected to both ends of the second drive module 40. Specifically, the first output terminal 410 and the second output terminal 420 of the second drive module 40 are respectively connected to the output terminal of the rectifier unit 3440. One end of the responder 520 is connected to the common terminal of the positive output terminal of the rectifier unit 3440 and the first output terminal 410, and the other end of the responder 520 is connected to the common terminal of the negative output terminal of the rectifier unit 3440 and the second output terminal 420.

[0054] Since both the fuse circuit 320 and the second drive module 40 are connected in parallel across the responder 520, the fuse circuit 320 outputs a pulse voltage signal to the second drive module 40 when it is in the blown state. The polarity of this pulse voltage signal is determined by the current direction in the branch containing the external load circuit. Under normal circumstances, the polarity of the pulse voltage signal is consistent with the polarity of the output voltage of the second drive module 40. However, if the external load circuit is reversed between the first connection terminal 10 and the second connection terminal 20, the voltage signal output by the fuse circuit 320 to the second drive module 40 will be a reverse pulse voltage signal. If this reverse pulse voltage signal is directly applied to the second drive module 40, it may cause damage to the second drive module 40. In this embodiment, a rectifier unit 3440 is connected between the fuse circuit 320 and the second drive module 40. The rectifier unit 3440 can correct the polarity of the reverse pulse voltage signal, ensuring that the polarity of the corrected reverse pulse voltage signal matches the polarity of the voltage signal output by the second drive module 40. This prevents the reverse pulse voltage signal from damaging the second drive module 40. Specifically, the rectifier unit 3440 can be a rectifier bridge.

[0055] In some embodiments, the detection circuit 340 further includes a Zener diode 3460, with its positive terminal connected to the first output terminal 410 and its negative terminal connected to the positive output terminal of the rectifier module 3440. The Zener diode 3460 is used to prevent the trigger current from being shunted by the rectifier unit 3440 when the second drive module 40 sends a trigger current to the responder 520 through the second connector 80 in reverse connection. Taking a twisted-pair cable as an example, reverse pin connections may occur during the fabrication of the twisted-pair cable. It should be noted that in this embodiment, the first output terminal 410 is the positive terminal, i.e., the trigger current output terminal. When the second connector 80 is not reverse-connected, when the trigger current flowing from the first output terminal 410 passes through the positive output terminal of the rectifier unit 3440, the rectifier unit 3440 is reverse-cut off, and the trigger current flows to the responder 520, causing the responder 520 to be in a triggered state. However, when the second connector 80 is reversed, the trigger current flowing out of the first output terminal 410 flows to the negative output terminal of the rectifier unit 3440. At this time, the rectifier unit 3440 is forward-biased, so the trigger current does not flow to the responder 520. That is, the second drive module 40 cannot control the responder 520 to enter the trigger state.

[0056] In this embodiment, a Zener diode 3460 is added to the detection circuit 340. When the detection voltage generated when the fuse circuit 320 blows is applied to the two ends of the Zener diode 3460, the Zener diode 3460 is in a reverse breakdown state. Therefore, when the second connector 80 is reverse-connected, when the trigger current flowing from the rectifier unit 3440 passes through the Zener diode 3460, the voltage across the Zener diode 3460 is less than the critical value. At this time, the Zener diode 3460 is in a reverse cutoff state. Therefore, the trigger current flows to the responder 520, making the responder 520 in a triggered state, ensuring the normal operation of the responder 520. In some embodiments, the rated voltage of the Zener diode 3460 is 3.9V and the rated power is 1W. This application embodiment does not limit the model and hardware parameters of the Zener diode 3460.

[0057] In some embodiments, the detection circuit 340 may further include a suppression unit 3480, which is connected in parallel to the first output terminal 410 and the second output terminal 420. The suppression unit 3480 is used to suppress the spike voltage signal generated when the responder 520 is in the triggered state, preventing the second drive module 40 from being damaged due to excessively large spike voltage signals. (See also...) Figure 7In some embodiments, the suppression unit 3480 includes a transient suppressor 3482 and a suppression capacitor 3484, which are connected in parallel to the first output terminal 410 and the second output terminal 420, respectively. For example, the transient suppressor 3482 has a rated voltage of 24V and a rated power of 200W. This embodiment does not limit the model or hardware parameters of the transient suppressor 3482 and the suppression capacitor 3484. Furthermore, the suppression capacitor 3484 can also filter out high-frequency surges between the first output terminal 410 and the second output terminal 420, ensuring the service life of the second drive module 40. In other embodiments, the suppression unit 3480 may include only the transient suppressor 3482, or only the suppression capacitor 3484.

[0058] This application discloses a short-circuit protection circuit. The short-circuit protection circuit is connected to an external load circuit via a first connection terminal and a second connection terminal. A fuse and a circuit breaker are connected in series between the first and second connection terminals, and the circuit breaker is connected to a responder. In this application, the responder is connected to a detection circuit connected in parallel across the fuse. When the fuse is in a blown state, the detected voltage across the fuse is greater than a specified voltage. At this time, the responder triggers the circuit breaker to disconnect the circuit between the first and second connection terminals. Therefore, in the event of a short circuit in the external load circuit, the fuse blows, triggering the circuit breaker to disconnect the external load circuit. That is, the circuit breaker module can quickly disconnect the external load circuit without connecting an external driver, saving hardware costs.

[0059] Furthermore, the short-circuit protection circuit in this application also includes an open-circuit detection module and a control module. The open-circuit detection module is connected in parallel across the two ends of the detection circuit. The control module is connected to the open-circuit detection module and determines whether the detection circuit is in an open-circuit state based on the port voltage obtained by the open-circuit detection module, that is, whether an open circuit has occurred in the line between the fuse circuit and the responder. Therefore, the short-circuit protection circuit in this application also has an open-circuit detection function, avoiding the situation where the fuse circuit fails to trigger the circuit breaker to cut off the external load circuit after blowing when an open circuit occurs in the line between the fuse circuit and the responder, thus ensuring the reliability of the connection between the fuse circuit and the responder.

[0060] In this application specification, certain terms are used to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. The specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to"; "generally" means that those skilled in the art can solve the technical problem within a certain margin of error and basically achieve the technical effect.

[0061] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description of this application and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0062] In this application, unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or merely surface contact. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, 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. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A short-circuit protection circuit, characterized in that, The short-circuit protection circuit has a first connection terminal and a second connection terminal for connecting to an external load circuit, and the short-circuit protection circuit includes: The first driving module includes a fuse circuit and a detection circuit. The fuse circuit is connected in series between the first connection terminal and the second connection terminal. The detection circuit is connected in parallel across the two ends of the fuse circuit to obtain the detection voltage across the two ends of the fuse circuit. The circuit breaking module includes a responder and a circuit breaker. The circuit breaker is connected in series with the fuse between the first connection terminal and the second connection terminal. The responder is connected to the detection circuit and the circuit breaker. The responder is used to trigger the circuit breaker to disconnect the circuit between the first connection terminal and the second connection terminal when the detected voltage is greater than a specified voltage. The circuit breaker detection module has a first detection port and a second detection port, which are connected in parallel across the two ends of the detection circuit; wherein, the circuit breaker detection module includes a power supply submodule, a switch submodule and a voltage detection submodule; The voltage detection submodule is connected in parallel across the first and second detection ports and connected to the control module; the switch submodule is connected between the voltage detection submodule and the power supply submodule and connected to the control module. The control module is further configured to: send a trigger signal to the switch submodule, the trigger signal being used to trigger the switch submodule to enter a conducting state; and, when the switch submodule is in the conducting state, acquire the port voltages of the first and second detection ports; and The control module is connected to the circuit breaker detection module and is configured to: acquire the port voltages of the first detection port and the second detection port, and determine whether the detection circuit is in an open circuit state based on the port voltages.

2. The short-circuit protection circuit according to claim 1, characterized in that, The switching submodule includes a first transistor, a second transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor; The first transistor is a PNP transistor. The emitter of the first transistor is connected to the power supply submodule through the first resistor. The collector of the first transistor is connected to the first detection port. The base of the first transistor is connected to the collector of the second transistor through the third resistor. The second transistor is an NPN transistor, and its emitter is connected to the second detection port and grounded; the base of the second transistor is connected to the control module through the fourth resistor. One end of the second resistor is connected to the common connection terminal of the first resistor and the emitter of the first transistor; the other end is connected to the common connection terminal of the base of the first transistor and the third resistor.

3. The short-circuit protection circuit according to claim 2, characterized in that, The power supply submodule includes a voltage power supply, a fifth resistor, and a capacitor; The fifth resistor is connected in series between the voltage power supply and the first resistor; One end of the capacitor is connected to the common connection terminal of the first resistor and the fifth resistor, and the other end is grounded.

4. The short-circuit protection circuit according to any one of claims 1 to 3, characterized in that, The detection circuit includes an isolation transformer unit, the primary side of which is electrically connected to both ends of the fuse circuit; the secondary side of which is electrically connected to both ends of the responder and is connected in parallel with the first detection port and the second detection port.

5. The short-circuit protection circuit according to any one of claims 1 to 3, characterized in that, The short-circuit protection circuit also includes a second drive module; The second drive module is electrically connected to the responder and is configured to generate a trigger current in the event of a short circuit in the external load circuit to trigger the circuit breaker to disconnect the circuit between the first connection terminal and the second connection terminal.

6. The short-circuit protection circuit according to claim 5, characterized in that, The detection circuit further includes a rectifier unit, the input of which is connected to both ends of the fuse circuit, and the output of which is connected to both ends of the second drive module.

7. The short-circuit protection circuit according to claim 6, characterized in that, The second driving module includes a first output terminal and a second output terminal, which are respectively connected to the output terminal of the rectifier unit; wherein, one end of the responder is connected to the common terminal of the positive output terminal of the rectifier unit and the first output terminal, and the other end of the responder is connected to the common terminal of the negative output terminal of the rectifier unit and the second output terminal. The detection circuit also includes a Zener diode, the positive terminal of which is connected to the first output terminal, and the negative terminal of which is connected to the positive output terminal of the rectifier unit.

8. The short-circuit protection circuit according to claim 7, characterized in that, The detection circuit further includes a suppression unit, which is connected in parallel to the first output terminal and the second output terminal; the suppression unit includes a transient suppressor and / or a suppression capacitor.

9. A power battery pack, characterized in that, include: Battery pack; as well as The short-circuit protection circuit according to any one of claims 1-8, wherein the first connection terminal and the second connection terminal of the short-circuit protection circuit are respectively connected to the positive and negative terminals of the battery pack.

10. A vehicle, characterized in that, include: case; as well as The power battery pack as described in claim 9, wherein the power battery pack is disposed within the housing.

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