Short circuit protection self-locking circuit and battery management system

Abstract

This application discloses a short-circuit protection self-locking circuit and a battery management system. The short-circuit protection self-locking circuit, used in a battery management system, includes: a short-circuit detection module connected in series in the power output path corresponding to the output port of the battery management system, used to output a short-circuit detection signal when a short circuit is detected in the power output path; a switching module connected in series in the power output path, used to control the on / off state of the power output path; and a self-locking control module connected to the output terminal of the short-circuit detection module and the controlled terminal of the switching module, used to switch to a second state in response to the short-circuit detection signal in a first state and control the switching module to disconnect the power output path, and in the second state in response to a reset signal to switch to the first state and control the switching module to connect the power output path. The technical solution of this application achieves continuous maintenance of the disconnected state through the self-locking control module, avoiding the risk of secondary damage that may result from automatic circuit recovery after the short circuit is cleared.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a short-circuit protection self-locking circuit and a battery management system. Background Technology

[0002] The Battery Management System (BMS) is a core component for the safe and stable operation of lithium-ion battery packs, widely used in new energy vehicles, energy storage power stations, and portable electronic devices. The BMS is primarily responsible for real-time monitoring and management of the battery pack's charge and discharge status, preventing dangerous conditions such as overcharging, over-discharging, and abnormal current, thus ensuring the safety and lifespan of the battery pack. With the continuous increase in battery pack capacity and the diversification of application scenarios, higher demands are placed on the safety protection functions of the BMS, especially in the event of serious faults such as short circuits, requiring the BMS to quickly and reliably disconnect the circuit to prevent further escalation of the fault.

[0003] To address these requirements, protection circuits composed of switching transistors are commonly used to control the on / off state of the main circuit. In abnormal conditions such as short circuits, the BMS controls the switching transistors, such as bipolar transistors or MOSFETs, to turn on or off via drive signals, thereby cutting off the main current path.

[0004] However, in practical applications, if the circuit automatically recovers after a short-circuit fault is cleared, it may cause secondary damage to the battery and load at the moment of power-on. Therefore, the industry has placed greater emphasis on and demand for a self-locking protection mechanism that can automatically remain disconnected after a short circuit is detected and only resume operation upon receiving a new reset signal. Consequently, designing a BMS self-locking control circuit that is simple in structure, fast in response, highly reliable, and can effectively maintain the disconnected state to prevent repeated short-circuit faults has become a pressing technical problem in this field. Utility Model Content

[0005] One objective of this application is to provide a short-circuit protection self-locking circuit and a battery management system, which aims to solve the technical problem that the battery management system is prone to secondary faults during the short-circuit reset process.

[0006] To achieve the above objectives, in a first aspect, this application provides a short-circuit protection self-locking circuit, comprising: a short-circuit detection module connected in series in the power output path corresponding to the output port of the battery management system, for outputting a short-circuit detection signal when a short circuit is detected in the power output path; a switch module connected in series in the power output path, for controlling the on / off state of the power output path; and a self-locking control module connected to the output terminal of the short-circuit detection module and the controlled terminal of the switch module, for switching to a second state in response to the short-circuit detection signal in a first state and controlling the switch module to disconnect the power output path, and switching to the first state in response to a reset signal in the second state and controlling the switch module to connect the power output path.

[0007] The technical solution of this application connects a short-circuit detection module and a switching module in series in the power output path of the battery management system, and sets up a self-locking control module. When the short-circuit detection module detects a short circuit in the output path, it can output a short-circuit detection signal. The self-locking control module responds to the signal, controls the switching module to disconnect the power output path, and enters a locked second state. When a reset signal is received, that is, after a reset operation is performed, the self-locking control module will return to the first state and control the switching module to conduct again, thereby restoring the power output path.

[0008] The technical solution of this application can not only quickly cut off the power output path when a short circuit is detected to prevent the short circuit fault from causing equipment damage, but also realize the continuous maintenance of the disconnected state through the self-locking control module. Normal output is only allowed to be restored after a reset operation, avoiding the risk of secondary damage that may be caused by the automatic recovery of the circuit after the short circuit is removed, thereby improving the safety and reliability of the battery management system.

[0009] In conjunction with the first aspect, according to one embodiment of this application, the first controlled terminal of the self-locking control module is used to receive a short-circuit detection signal, the second controlled terminal of the self-locking control module is used to receive a reset signal, and the output terminal of the self-locking control module is connected to the switch module.

[0010] In this embodiment, the self-locking control module is provided with a first controlled terminal and a second controlled terminal, which are used to receive short-circuit detection signals and reset signals, respectively. By providing the first and second controlled terminals, the self-locking control module can respond independently to the short-circuit detection signal and the reset signal, achieving precise control of the circuit state. When a short circuit is detected, the first controlled terminal receives the short-circuit detection signal, and the self-locking control module switches to the second state, controlling the switching module to disconnect the power output path. When output needs to be restored, the second controlled terminal receives the reset signal, and the self-locking control module switches to the first state, controlling the switching module to close the power output path again. This structural design makes short-circuit protection and restoration operations independent of each other, improving system safety and operational flexibility.

[0011] In conjunction with the first aspect, according to one embodiment of this application, the self-locking control module includes: a first switching transistor connected between the output terminal of the self-locking control module and a fixed low level, wherein the controlled terminal of the first switching transistor serves as the first controlled terminal of the self-locking control module; a first resistor connected between the controlled terminal of the first switching transistor and the first fixed low level; a second switching transistor connected between the controlled terminal of the first switching transistor and a second controlled terminal of the self-locking control module, wherein the controlled terminal of the second switching transistor serves as the output terminal of the self-locking control module; and a second resistor connected between the second controlled terminal of the self-locking control module and the controlled terminal of the second switching transistor.

[0012] In conjunction with the first aspect, according to one embodiment of this application, the first switching transistor is an N-type MOS transistor, and the second switching transistor is a P-type MOS transistor.

[0013] In conjunction with the first aspect, according to one embodiment of this application, the self-locking control module further includes a first capacitor connected between the second controlled terminal of the self-locking control module and the second fixed low level.

[0014] In conjunction with the first aspect, according to one embodiment of this application, it further includes an amplification module connected between the short-circuit detection module and the self-locking control module, for amplifying the short-circuit detection signal and outputting it to the self-locking control module.

[0015] In conjunction with the first aspect, according to one embodiment of this application, the short-circuit detection module includes a third resistor, the power output path includes a positive output terminal and a negative output terminal connected to the positive and negative terminals of the battery respectively, the negative output terminal is connected to the battery through the third resistor, and the amplification module includes a comparator, the first input terminal of the comparator is connected to the high-level terminal of the third resistor, the second input terminal of the comparator is connected to a reference voltage, and the output terminal of the comparator is connected to the controlled terminal of the self-locking control module.

[0016] In this embodiment, the comparator is configured to accurately detect changes in the current of the power output path. Specifically, the first input terminal of the comparator is connected to the high-level terminal of the third resistor, and the second input terminal is connected to a reference voltage. When a short circuit occurs in the load of the battery management system, the negative output terminal of the power output path is pulled high by the positive output terminal, that is, the high-level terminal of the third resistor rises above the reference voltage, thereby causing the comparator to flip. The output terminal of the comparator outputs a high level, which in turn outputs a short-circuit detection signal to the self-locking control module.

[0017] The introduction of the comparator provides a clear threshold for short-circuit detection, mitigating false triggering caused by transient voltage fluctuations or jitters in the power output path. Only when an actual short circuit occurs, causing an abnormal increase in current, will the voltage at the high-level terminal of the third resistor exceed the reference voltage, triggering the comparator to output a short-circuit detection signal. This improves the accuracy and stability of short-circuit detection, reduces the probability of malfunctions, and further enhances the reliability and practicality of the battery management system.

[0018] In conjunction with the first aspect, according to one embodiment of this application, the amplification module further includes: a fourth resistor and a fifth resistor connected in series between a fixed high level and a third fixed low level, wherein the connection node between the fourth resistor and the fifth resistor is connected to the second input terminal of the comparator for outputting a reference voltage.

[0019] In conjunction with the first aspect, according to one embodiment of this application, the amplification module further includes: a sixth resistor and a second capacitor connected in series between the high-level end of the third resistor and the fourth fixed low-level end, wherein the connection node between the sixth resistor and the second capacitor is connected to the first input terminal of the comparator for filtering the short-circuit detection signal.

[0020] In conjunction with the first aspect, according to one embodiment of this application, the switching module includes a third switching transistor connected in series in the power output path, and the controlled terminal of the third switching transistor serves as the controlled terminal of the switching module.

[0021] Secondly, this application also provides a battery management system for managing batteries, including the short-circuit protection self-locking circuit of any of the above embodiments.

[0022] The beneficial effects of the second aspect can be referred to in the first aspect or any possible implementation of the first aspect, and will not be elaborated here. Based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations.

[0023] Other advantages, objectives and features of this application will be partly apparent from the description below, and partly understood by those skilled in the art through study and practice of this application. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1This is a circuit diagram of the battery management system used in the embodiments of this application.

[0026] Figure 2 This is a partial circuit diagram of the short-circuit protection self-locking circuit provided in the embodiments of this application.

[0027] Explanation of icon numbers: 101. Short circuit detection module; 102. Switch module; 103. Self-locking control module; 104. Battery; 105. Main control unit; 106. Monitoring unit; 201. Amplification module; R1. First resistor; R2. Second resistor; R3. Third resistor; R4. Fourth resistor; R5. Fifth resistor; R6. Sixth resistor; C1. First capacitor; C2. Second capacitor; Q1. First switching transistor; Q2. Second switching transistor; Q3. Third switching transistor; GND. Ground; V0. Fixed high level. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0029] With the widespread application of lithium-ion batteries in new energy vehicles, energy storage power stations, and portable electronic devices, the Battery Management System (BMS), as a crucial unit ensuring the safe and stable operation of battery packs, is receiving increasing attention for its safety protection functions. Existing BMSs typically use switching transistors (such as MOSFETs or bipolar transistors) to control the on / off state of the power output path. In practical applications, when the BMS detects an abnormality such as a short circuit in the battery output path, it will promptly drive the switching transistor to disconnect the circuit, thereby effectively preventing damage to the battery and downstream loads caused by the short circuit fault.

[0030] However, most current BMS protection circuits tend to automatically restore the output path after a short-circuit fault is cleared. This automatic restoration method can pose risks in certain scenarios: if the short circuit is not completely eliminated or there is a current surge during restoration, it can easily cause secondary damage to the battery and load, or even lead to system instability. Therefore, the industry has raised higher requirements for circuits with self-locking protection mechanisms, requiring the circuit to remain open after detecting a short circuit and only allowing the output to resume upon receiving a clear reset signal. This requirement presents a greater challenge to the safety and reliability of battery management systems and has become a problem that urgently needs to be solved by current technology.

[0031] Please refer to Figure 1 and Figure 2 As shown, in a first aspect, to solve the above-mentioned technical problems, this application provides a short-circuit protection self-locking circuit, including: a short-circuit detection module 101, connected in series in the power output path corresponding to the output port of the battery management system, for outputting a short-circuit detection signal when a short circuit is detected in the power output path; a switch module 102, connected in series in the power output path, for controlling the on / off state of the power output path; and a self-locking control module 103, connected to the output terminal of the short-circuit detection module 101 and the controlled terminal of the switch module 102 respectively, for switching to a second state in response to the short-circuit detection signal in a first state and controlling the switch module 102 to disconnect the power output path, and switching to the first state in response to a reset signal in the second state and controlling the switch module 102 to connect the power output path.

[0032] The technical solution of this application connects a short-circuit detection module 101 and a switch module 102 in series in the power output path of the battery management system, and sets up a self-locking control module 103. When the short-circuit detection module 101 detects a short circuit in the output path, it can output a short-circuit detection signal. The self-locking control module 103 responds to the signal, controls the switch module 102 to disconnect the power output path, and enters a locked second state. When a reset signal is received, that is, after a reset operation is performed, the self-locking control module 103 will return to the first state and control the switch module 102 to turn on again, thereby restoring the power output path.

[0033] It should be understood that the "short circuit in the power output path" referred to in this application should be understood as a surge in current on the power output path, and does not necessarily mean that the specific fault occurs in the wires of the power output path itself. Common causes of short circuits in the power output path include battery pack short circuits, load short circuits, and improper installation leading to short circuits between the two output terminals.

[0034] The technical solution of this application can not only quickly cut off the power output path when a short circuit is detected to prevent the short circuit fault from causing equipment damage, but also realize the continuous maintenance of the disconnected state through the self-locking control module 103. Normal output is only allowed to be restored after a reset operation, avoiding the risk of secondary damage that may be caused by the automatic recovery of the circuit after the short circuit is removed, thereby improving the safety and reliability of the battery management system.

[0035] In conjunction with the first aspect, according to one embodiment of this application, the first controlled terminal of the self-locking control module 103 is used to receive a short-circuit detection signal, the second controlled terminal of the self-locking control module 103 is used to receive a reset signal, and the output terminal of the self-locking control module 103 is connected to the switch module 102.

[0036] In this embodiment, the self-locking control module 103 is provided with a first controlled terminal and a second controlled terminal, which are used to receive short-circuit detection signals and reset signals, respectively. By providing the first and second controlled terminals, the self-locking control module 103 can respond independently to the short-circuit detection signal and the reset signal, achieving precise control of the circuit state. When a short circuit is detected, the first controlled terminal receives the short-circuit detection signal, and the self-locking control module 103 switches to the second state, controlling the switch module 102 to disconnect the power output path. When output needs to be restored, the second controlled terminal receives the reset signal, and the self-locking control module 103 switches to the first state, re-controlling the switch module 102 to close the power output path. This structural design makes short-circuit protection and restoration operations independent of each other, improving system safety and operational flexibility.

[0037] Specifically, the self-locking control module 103 includes: a first switch Q1 connected between the output terminal of the self-locking control module 103 and a fixed low level, with the controlled terminal of the first switch Q1 serving as the first controlled terminal of the self-locking control module 103; a first resistor R1 connected between the controlled terminal of the first switch Q1 and the first fixed low level; a second switch Q2 connected between the controlled terminal of the first switch Q1 and the second controlled terminal of the self-locking control module 103, with the controlled terminal of the second switch Q2 serving as the output terminal of the self-locking control module 103; and a second resistor R2 connected between the second controlled terminal of the self-locking control module 103 and the controlled terminal of the second switch Q2.

[0038] In this embodiment, the controlled terminal of the first switch Q1 is connected to the second switch Q2, and the controlled terminal of the second switch Q2 is connected to the first switch Q1. The switch can be a transistor or a MOSFET, etc. Here, the operating principle of the self-locking control module 103 is explained with a specific component configuration of the self-locking control module 103.

[0039] For example, the first switch Q1 is an N-type MOSFET and the second switch Q2 is a P-type MOSFET.

[0040] The first controlled terminal of the self-locking control module 103 receives a low level when there is no short circuit in the power output path, and the second controlled terminal of the self-locking control module 103 receives a high level when there is no short circuit in the power output path. The short circuit detection signal is high level, and the reset signal is low level.

[0041] It's important to note that the high and low levels here are relative concepts, without absolute numerical limitations. The key is to achieve the switching between on and off states of the MOSFET. For example, for an N-type MOSFET, the MOSFET is on when the gate voltage is higher than the source voltage (i.e., a high level is applied), and off when the gate voltage is lower than the threshold voltage (i.e., a low level is applied). For a P-type MOSFET, the MOSFET is on when the gate voltage is lower than the source voltage (i.e., a low level is applied), and off when the gate voltage is higher than the threshold voltage (i.e., a high level is applied). In practical applications, the high and low levels of the control signal should be configured appropriately according to the type of MOSFET selected.

[0042] In this embodiment, when the self-locking control module 103 is in the first state, both the first switch Q1 and the second switch Q2 are in the off state, and the output terminal of the self-locking control module 103 is disconnected from the first fixed low level, thus synchronizing its second controlled terminal to a high level. When the first controlled terminal of the self-locking control module 103 receives a high-level short-circuit detection signal, the gate (G) of the first switch Q1 is pulled high, and the first switch Q1 is turned on. The gate (G) voltage of the second switch Q2 and the output terminal voltage of the self-locking control module 103 are both pulled low to the first fixed low level. On the one hand, a turn-off signal is output to the switch module 102; on the other hand, the second switch Q2 is turned on, so that the gate (G) voltage of the first switch Q1 remains at a high level synchronized with the second controlled terminal of the self-locking control module 103. At this point, the self-locking control module 103 switches to the second state, and even if the short-circuit detection signal disappears, the self-locking control module 103 will remain in the second state.

[0043] When the second controlled terminal of the self-locking control module 103 receives a low-level reset signal, this reset signal can be automatically issued by the program after determining that sufficient reset conditions are met, or it can be issued manually by the maintenance personnel. When the second switch Q2 is turned on, the gate of the first switch Q1 is pulled low, the first switch tube is turned off, the gate of the second switch Q2 is disconnected from the first fixed low level, the second switch Q2 is turned off, and the self-locking control module 103 is reset to the first state.

[0044] For example, the self-locking control module 103 also includes a first capacitor C1, which is connected between the second controlled terminal and the second fixed low level of the self-locking control module 103.

[0045] The first capacitor C1 is mainly used to filter and delay the reset signal of the self-locking control module 103, thereby achieving a stable current effect during the reset process. Specifically, when the second controlled terminal of the self-locking control module 103 switches from a high level to a low level, the first capacitor C1 will buffer the voltage change for a short time, so that the potential change of the second controlled terminal has a certain delay, thereby preventing the self-locking control module 103 from being erroneously reset due to short-term interference pulses, effectively improving the anti-interference capability and stability of the system.

[0046] In conjunction with the first aspect, according to one embodiment of this application, it further includes an amplification module 201 connected between the short-circuit detection module 101 and the self-locking control module 103, for amplifying the short-circuit detection signal and outputting it to the self-locking control module 103.

[0047] In practical applications, short-circuit detection signals are easily affected by external interference or signal attenuation, causing the self-locking control module 103 to fail to accurately identify the short-circuit state, thereby affecting the protection effect of the system. The amplification module 201 not only effectively improves the amplitude and driving capability of the short-circuit detection signal, ensuring that the self-locking control module 103 can respond to the short-circuit detection signal in a timely and accurate manner, preventing misjudgment or missed judgment due to weak signal, but also performs certain shaping and anti-interference processing on the signal, improving the working stability and reliability of the entire system in complex electromagnetic environments, and ensuring the safe operation of sensitive loads.

[0048] In conjunction with the first aspect, according to one embodiment of this application, the short-circuit detection module 101 includes a third resistor R3, the power output path includes a positive output terminal and a negative output terminal respectively connected to the positive and negative terminals of the battery 104, the negative output terminal is connected to the battery 104 through the third resistor R3, and the amplification module 201 includes a comparator, the first input terminal of the comparator is connected to the high-level terminal of the third resistor R3, the second input terminal of the comparator is connected to a reference voltage, and the output terminal of the comparator is connected to the controlled terminal of the self-locking control module 103.

[0049] In this embodiment, the comparator is configured to accurately detect changes in the current of the power output path. Specifically, the first input terminal of the comparator is connected to the high-level terminal of the third resistor R3, and the second input terminal is connected to a reference voltage. When a short circuit occurs in the load of the battery management system, the negative output terminal of the power output path is pulled high by the positive output terminal, that is, the high-level terminal of the third resistor R3 rises above the reference voltage, thereby causing the comparator to flip. The output terminal of the comparator outputs a high level, that is, it outputs a short-circuit detection signal to the self-locking control module 103.

[0050] The introduction of the comparator provides a clear threshold for short-circuit detection, mitigating false triggering caused by transient voltage fluctuations or jitters in the power output path. Only when an actual short circuit occurs, causing an abnormal increase in current, will the voltage at the high-level terminal of the third resistor R3 exceed the reference voltage, triggering the comparator to output a short-circuit detection signal. This improves the accuracy and stability of short-circuit detection, reduces the probability of malfunctions, and further enhances the reliability and practicality of the battery management system.

[0051] For example, the amplification module 201 further includes a fourth resistor R4 and a fifth resistor R5 connected in series between a fixed high level V0 and a third fixed low level, wherein the connection node between the fourth resistor R4 and the fifth resistor R5 is connected to the second input terminal of the comparator for outputting a reference voltage.

[0052] The embodiment provides a specific implementation of a reference voltage. The sum of the voltage drops of the fourth resistor R4 and the fifth resistor R5 is the voltage between the fixed high level V0 and the third fixed low level. The ratio of the voltage drops of the fourth resistor R4 and the fifth resistor R5 is the ratio of their resistance values. By balancing the resistance ratio of the fourth resistor R4 and the fifth resistor R5, the required reference voltage can be flexibly adjusted between the fixed high level V0 and the third fixed low level.

[0053] For example, the amplification module 201 further includes: a sixth resistor R6 and a second capacitor C2 connected in series between the high-level end of the third resistor R3 and the fourth fixed low-level end, the connection node between the sixth resistor R6 and the second capacitor C2 being connected to the first input terminal of the comparator for filtering the short-circuit detection signal.

[0054] In this embodiment, the setting of the sixth resistor R6 and the second capacitor C2 can effectively suppress external electromagnetic interference and high-frequency noise, improve the purity and stability of the short-circuit detection signal, avoid false triggering, and further improve the accuracy of the comparator input signal.

[0055] It should be understood that the first fixed low level, the second fixed low level, the third fixed low level and the fourth fixed low level referred to in this application can be set individually, or they can be connected to a certain low level source, such as the ground GND of the battery management system, or the total negative terminal of battery 104.

[0056] In conjunction with the first aspect, according to one embodiment of this application, the switching module 102 includes a third switching transistor Q3 connected in series in the power output path, and the controlled terminal of the third switching transistor Q3 serves as the controlled terminal of the switching module 102.

[0057] In this embodiment, the switching module 102 uses a switching transistor such as a MOSFET. Upon detecting a short circuit, it can quickly disconnect the power output path within a very short time, effectively protecting the downstream circuitry and the load. Furthermore, the high input impedance of the switching transistor reduces its requirements for control signal drive, facilitating integration with front-end amplification and filtering modules, ensuring the entire short-circuit protection system is both efficient and reliable. By connecting the switching transistor in series with the main power path, the system can quickly disconnect high current and high loads, further enhancing the safety and lifespan of the battery 104 or sensitive devices.

[0058] Secondly, to solve the above problems, this application also provides a battery management system for managing the battery 104, including the short-circuit protection self-locking circuit of any of the above embodiments.

[0059] Since the battery management system provided in the second aspect of this application includes the short-circuit protection lock-up circuit of the above embodiments, the battery management system has the technical effects of the short-circuit protection lock-up circuit described above. Based on the implementation methods provided in the above aspects, this application can also make further combinations to provide more implementation methods.

[0060] In conjunction with the second aspect, according to one embodiment of this application, it further includes: a main control unit 105, which is used to receive the on / off signal of the power output path and output a reset signal; The monitoring unit 106 is connected to the main control unit 105 and is used to monitor the working status of the battery 104, such as humidity and temperature, and transmit the data to the main control unit 105.

[0061] The setup of the main control unit 105 and the monitoring unit 106 enables the system to not only promptly detect changes in the power output path, but also to adjust the system based on the monitored state of the battery 104, effectively improving the intelligence and safety of battery 104 management and ensuring the stable operation of the battery 104 and the electrical equipment.

[0062] The beneficial effects of the second aspect can be referred to in the first aspect or any possible implementation of the first aspect, and will not be elaborated here. Based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations.

[0063] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0064] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0065] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many forms under the guidance of this application without departing from the spirit and scope of protection of the claims. All equivalent transformations made based on the content of this application's specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of this application.

Claims

1. A short-circuit protection self-locking circuit, characterized in that, include: A short-circuit detection module is connected in series in the power output path corresponding to the output port of the battery management system, and is used to output a short-circuit detection signal when a short circuit is detected in the power output path; A switching module, connected in series in the power output path, is used to control the on / off state of the power output path; The self-locking control module is connected to the output terminal of the short-circuit detection module and the controlled terminal of the switch module, respectively. It is used to switch to the second state in response to the short-circuit detection signal in the first state and control the switch module to disconnect the power output path, and in the second state, to switch to the first state in response to the reset signal and control the switch module to turn on the power output path.

2. The short-circuit protection self-locking circuit according to claim 1, characterized in that, The first controlled terminal of the self-locking control module is used to receive the short-circuit detection signal, the second controlled terminal of the self-locking control module is used to receive the reset signal, and the output terminal of the self-locking control module is connected to the switch module.

3. The short-circuit protection self-locking circuit according to claim 2, characterized in that, The self-locking control module includes: The first switching transistor is connected between the output terminal of the self-locking control module and a fixed low level, and the controlled terminal of the first switching transistor serves as the first controlled terminal of the self-locking control module. The first resistor is connected between the controlled terminal of the first switching transistor and the first fixed low level. The second switch is connected between the controlled terminal of the first switch and the second controlled terminal of the self-locking control module, and the controlled terminal of the second switch serves as the output terminal of the self-locking control module. The second resistor is connected between the second controlled terminal of the self-locking control module and the controlled terminal of the second switching transistor.

4. The short-circuit protection self-locking circuit according to claim 3, characterized in that, The first switching transistor is an N-type MOSFET, and the second switching transistor is a P-type MOSFET.

5. The short-circuit protection self-locking circuit according to claim 3, characterized in that, The self-locking control module also includes a first capacitor, which is connected between the second controlled terminal and the second fixed low level of the self-locking control module.

6. The short-circuit protection self-locking circuit according to claim 1, characterized in that, It also includes an amplification module connected between the short-circuit detection module and the self-locking control module, used to amplify the short-circuit detection signal and output it to the self-locking control module.

7. The short-circuit protection self-locking circuit according to claim 6, characterized in that, The short-circuit detection module includes a third resistor, the power output path includes a positive output terminal and a negative output terminal connected to the positive and negative terminals of the battery respectively, the negative output terminal is connected to the battery through the third resistor, and the amplification module includes: The comparator has its first input terminal connected to the high-level terminal of the third resistor, its second input terminal connected to a reference voltage, and its output terminal connected to the controlled terminal of the self-locking control module.

8. The short-circuit protection self-locking circuit according to claim 7, characterized in that, The amplification module further includes a fourth resistor and a fifth resistor connected in series between a fixed high level and a third fixed low level. The connection node between the fourth resistor and the fifth resistor is connected to the second input terminal of the comparator for outputting the reference voltage.

9. The short-circuit protection self-locking circuit according to claim 7, characterized in that, The amplification module further includes a sixth resistor and a second capacitor connected in series between the high-level end of the third resistor and the fourth fixed low-level end. The connection node between the sixth resistor and the second capacitor is connected to the first input terminal of the comparator for filtering the short-circuit detection signal.

10. The short-circuit protection self-locking circuit according to any one of claims 1-9, characterized in that, The switching module includes a third switching transistor connected in series in the power output path, and the controlled terminal of the third switching transistor serves as the controlled terminal of the switching module.

11. A battery management system for managing batteries, characterized in that, Includes the short-circuit protection self-locking circuit according to any one of claims 1-10.

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