Anti-reverse-connection short-circuit protection circuit and battery management system

Abstract

The utility model provides an anti-reverse-connection short-circuit protection circuit. The anti-reverse-connection short-circuit protection circuit comprises a first electronic switching tube, a second electronic switching tube, a first resistor, a second resistor and a third resistor. And the microcontroller and the operational amplifier are used for detecting an abnormal state in the circuit and outputting a level signal to control the second electronic switching tube. When the circuit is short-circuited, the operational amplifier and the microcontroller can respectively output high-level signals, so that the second electronic switching tube is conducted, the first electronic switching tube is cut off, a charging loop is cut off, and then double short-circuit protection is provided. And meanwhile, an internal parasitic diode of the first electronic switching tube has unidirectional conductivity, so that the damage to the battery caused by reverse current when the charger is reversely connected can be effectively prevented. In addition, after the short-circuit fault is removed, the anti-reverse-connection short-circuit protection circuit can automatically recover the charging state, human intervention is reduced, the use cost is reduced, and the continuous operation capability is enhanced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery management systems, and in particular to a reverse connection short circuit protection circuit and a battery management system. Background Art

[0002] Amid the widespread application of power battery products, battery safety and reliability are core concerns. However, battery systems are prone to short-circuit failures and reverse current during operation. Reverse current and excessive short-circuit current can lead to battery overheating and overcharging, significantly shortening battery life and potentially causing fires and explosions. Furthermore, reverse current can trigger unexpected chemical reactions within the battery, damaging its internal structure and even causing leakage or swelling. Therefore, adding reverse polarity protection and short-circuit protection circuits to the battery management system can effectively prevent damage to the battery caused by reverse current, improve the reliability and safety of the battery system, and reduce maintenance costs.

[0003] In existing technologies, commonly used reverse polarity protection circuits typically use components such as diodes. However, diodes still have certain limitations in terms of cost, efficiency, structural complexity, and response speed. Schottky diodes are more commonly used than silicon diodes due to their low forward voltage drop and reduced voltage loss. However, their high reverse leakage current limits their suitability to low-power applications. Furthermore, traditional short-circuit protection circuits use fuses as a simple and effective protection device. However, fuses cannot be restored after melting and require manual replacement, which increases usage costs and maintenance difficulties. Utility Model Content

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a reverse connection short circuit protection circuit and a battery management system that are simple in structure, self-recovering and have dual protection.

[0005] The purpose of this disclosure is achieved through the following technical solutions:

[0006] A reverse connection short circuit protection circuit includes a first electronic switch tube, a second electronic switch tube, a first resistor, a second resistor and a third resistor.

[0007] The control end of the first electronic switch tube is used to be connected to the control signal output end of the charger detection circuit, the first end of the first electronic switch tube is used to be connected to the output end of the charger detection circuit, the second end of the first electronic switch tube is used to be connected to the negative electrode of the battery, the first end of the second electronic switch tube is connected to the control end of the first electronic switch tube, the control end of the second electronic switch tube is used to be connected to the abnormal state signal output end of the microcontroller, the second end of the second electronic switch tube is grounded, the first end of the first resistor is used to be connected to the control signal output end of the charger detection circuit, the second end of the first resistor is connected to the control end of the first electronic switch tube, the first end of the second resistor is used to be connected to the output end of the operational amplifier, the second end of the second resistor is connected to the control end of the second electronic switch tube, the first end of the third resistor is respectively connected to the second end of the second resistor and the control end of the second electronic switch tube, and the second end of the third resistor is grounded.

[0008] In one embodiment, the anti-reverse short-circuit protection circuit further includes a first capacitor, a first end of the first capacitor is connected to the control end of the second electronic switch tube, and a second end of the first capacitor is grounded.

[0009] In one embodiment, the anti-reverse short-circuit protection circuit further includes a fourth resistor, a first end of the fourth resistor is connected to the abnormal state signal output end of the microcontroller, and a second end of the fourth resistor is connected to the control end of the second electronic switch tube.

[0010] In one embodiment, the anti-reverse short-circuit protection circuit further includes a fifth resistor, a first end of the fifth resistor is connected to the first end of the first electronic switch tube, and a second end of the fifth resistor is grounded.

[0011] In one embodiment, the reverse polarity short circuit protection circuit further includes a voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the first end of the first electronic switch tube, and the anode of the voltage stabilizing diode is grounded.

[0012] In one embodiment, the first electronic switch tube is an N-channel MOS tube.

[0013] In one embodiment, the second electronic switch tube is an NPN transistor.

[0014] In one embodiment, the first resistor is a current limiting resistor, and the second resistor is a voltage dividing resistor.

[0015] In one embodiment, the resistance ratio of the second resistor to the third resistor is 0.303.

[0016] A battery management system comprises the reverse connection short circuit protection circuit as described in any one of the above items.

[0017] Compared with the prior art, the present disclosure has at least the following advantages:

[0018] 1. In the aforementioned reverse polarity short-circuit protection circuit, when a short circuit occurs, the short-circuit signal output terminal of the operational amplifier outputs a high-level signal to the control terminal of the second electronic switch, turning the second electronic switch on. This in turn grounds the control terminal of the first electronic switch, cutting off the battery's charging circuit. Furthermore, upon detecting a short circuit, the microcontroller's abnormal status signal output terminal also outputs a high-level signal to the control terminal of the second electronic switch, keeping the second electronic switch on. This provides a dual short-circuit protection mechanism and improves the reliability of the reverse polarity short-circuit protection circuit.

[0019] 2. On the other hand, since the internal parasitic diode of the first electronic switch tube has unidirectional conductivity, it can effectively prevent reverse current from damaging the battery when the charger is reversely connected. Therefore, the reverse connection short-circuit protection circuit integrates the reverse connection protection and short-circuit protection functions, thereby reducing the number of components and simplifying the circuit design, thereby reducing the cost of using the reverse connection short-circuit protection circuit.

[0020] 3. Furthermore, when the short-circuit fault is removed, the reverse polarity short-circuit protection circuit can automatically restore to a normal charging state through the operational amplifier and the microcontroller, thereby reducing human intervention and enhancing the continuous operation capability of the reverse polarity short-circuit protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A circuit diagram of a reverse connection short circuit protection circuit according to an embodiment;

[0023] Figure 2 This is the working principle diagram of the reverse polarity short circuit protection circuit. DETAILED DESCRIPTION

[0024] To facilitate understanding of the present disclosure, a more comprehensive description of the present disclosure will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. The terms used herein in the specification of this disclosure are intended only to describe specific embodiments and are not intended to limit this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] In order to better understand the technical solutions and beneficial effects of the present disclosure, the present disclosure is further described in detail below with reference to specific embodiments:

[0028] like Figure 1 As shown, the reverse connection short circuit protection circuit 10 according to an embodiment of the present disclosure includes a first electronic switch tube MC1, a second electronic switch tube Q1, a first resistor R1, a second resistor R2 and a third resistor R3.

[0029] A control end of the first electronic switch tube MC1 is connected to the control signal output end CM of the charger detection circuit. A first end of the first electronic switch tube MC1 is connected to the output end of the charger detection circuit. A second end of the first electronic switch tube MC1 is connected to the negative electrode of the battery. A first end of the second electronic switch tube Q1 is connected to the control end of the first electronic switch tube MC1. The control end of the second electronic switch tube Q1 is connected to the abnormal state signal output end DO3 of the microcontroller. A second end of the second electronic switch tube Q1 is grounded. A first end of the first resistor R1 is connected to the control signal output end CM of the charger detection circuit. A second end of the first resistor R1 is connected to the control end of the first electronic switch tube MC1. A first end of the second resistor R2 is connected to the output end AD_CUR1 of the operational amplifier. A second end of the second resistor R2 is connected to the control end of the second electronic switch tube Q1. A first end of the third resistor R3 is connected to the second end of the second resistor R2 and the control end of the second electronic switch tube Q1, respectively. A second end of the second resistor R2 is further connected to the second end of the first electronic switch tube MC1 via the third resistor R3.

[0030] In this embodiment, when the charger is properly connected, the control signal output terminal CM of the charger detection circuit outputs a high-level signal to the first resistor R1. This high-level signal is then transmitted to the control terminal of the first electronic switch MC1, causing the voltage at the control terminal of the first electronic switch MC1 to exceed its threshold voltage, turning on the first electronic switch MC1 and allowing current to flow from the positive electrode of the battery to the negative electrode, thereby enabling normal charging. Simultaneously, the microcontroller continuously monitors the current state in the circuit. During normal charging, the output terminal AD_CUR1 of the operational amplifier continuously outputs a low-level signal to the control terminal of the second electronic switch Q1, keeping it in the off state. When the charger is reverse-connected, the unidirectional conduction of the internal parasitic diode of the first electronic switch MC1 prevents reverse current from damaging the battery. Furthermore, in the reverse-connection condition, the output signal at the control signal output terminal CM of the charger detection circuit drops to a low level, causing the voltage at the control terminal of the first electronic switch MC1 to fall below its threshold voltage, turning off the first electronic switch MC1 and further ensuring the effectiveness of the reverse-connection protection.

[0031] When a short circuit occurs in an electrical loop, the current in the loop will increase dramatically. After the operational amplifier receives the abnormal short-circuit current signal, the level signal output by the output terminal AD_CUR1 of the operational amplifier will also increase. Since the output terminal AD_CUR1 of the operational amplifier is connected to the control terminal of the second electronic switch tube Q1, when the output voltage is greater than the threshold voltage of the control terminal of the second electronic switch tube Q1, the second electronic switch tube Q1 is turned on, and the control terminal of the first electronic switch tube MC1 is connected to the ground terminal through the second electronic switch tube Q1 to form a loop, thereby reducing the voltage at the control terminal of the first electronic switch tube MC1 to zero, thereby turning off the first electronic switch tube MC1 and disconnecting the charging circuit to achieve short-circuit protection.

[0032] Specifically, when the microcontroller detects a short circuit, the abnormal state signal output terminal DO3 of the microcontroller will output a high-level signal to the control terminal of the second electronic switch tube Q1 to keep the control terminal voltage of the second electronic switch tube Q1 greater than its threshold voltage, thereby ensuring that the second electronic switch tube Q1 remains in the on state when a short circuit occurs in the circuit, and ensuring that the first electronic switch tube MC1 is in the off state, thereby improving the reliability of the short circuit protection of the anti-reverse short-circuit protection circuit 10.

[0033] Furthermore, after the short-circuit fault is removed, the output level signal of the output terminal AD_CUR1 of the operational amplifier gradually decreases, causing the voltage at the control terminal of the second electronic switch tube Q1 to decrease to its threshold voltage, thereby turning off the second electronic switch tube Q1. The control terminal of the first electronic switch tube MC1 regains the high-level signal output by the control signal output terminal CM of the charger detection circuit, thereby automatically restoring the circuit to a normal charging state. At the same time, after the microcontroller detects that the short-circuit fault has been removed, the abnormal state signal output terminal DO3 of the microcontroller stops outputting a high-level signal to the control terminal of the second electronic switch tube Q1, thereby ensuring that the circuit can complete the self-recovery function.

[0034] When a short circuit occurs in the aforementioned reverse polarity short-circuit protection circuit 10, the operational amplifier output terminal AD_CUR1 outputs a high-level signal to the control terminal of the second electronic switch Q1, turning on the second electronic switch Q1. This in turn grounds the control terminal of the first electronic switch MC1, cutting off the battery's charging circuit. Furthermore, after detecting a short circuit, the microcontroller's abnormal status signal output terminal also outputs a high-level signal to the control terminal of the second electronic switch Q1, keeping the second electronic switch Q1 in the on state. This provides a dual short-circuit protection mechanism and improves the reliability of the reverse polarity short-circuit protection circuit 10. Furthermore, because the internal parasitic diode of the first electronic switch MC1 is unidirectional, it effectively prevents reverse current from damaging the battery when the charger is reversely connected. Consequently, the reverse polarity short-circuit protection circuit 10 integrates both reverse polarity protection and short-circuit protection functions, reducing the number of components and simplifying the circuit design, thereby lowering the cost of the reverse polarity short-circuit protection circuit 10. Furthermore, when the short circuit fault is removed, the reverse polarity short circuit protection circuit 10 can automatically recover to a normal charging state through the operational amplifier and the microcontroller, thereby reducing human intervention and enhancing the continuous operation capability of the reverse polarity short circuit protection circuit 10.

[0035] like Figure 1 As shown, in one embodiment, the reverse polarity short-circuit protection circuit 10 further includes a first capacitor C1, a first end of the first capacitor C1 being connected to the control end of the second electronic switch Q1, and a second end of the first capacitor C1 being grounded. In this embodiment, the first capacitor C1 and the third resistor R3 together form an RC filter circuit, the primary function of which is to smooth and stabilize the level signal transmitted to the control end of the second electronic switch Q1, thereby reducing noise and interference in the signal, thereby improving the stability and reliability of the circuit. Specifically, due to the energy storage characteristics of the first capacitor C1, it can effectively absorb high-frequency noise and transient interference, thereby making the signal at the control end of the second electronic switch Q1 more stable. When a short circuit fault occurs in the circuit, the first capacitor C1 can quickly respond to signal changes, helping the second electronic switch Q1 stabilize the control signal, so that the second electronic switch Q1 can accurately respond and turn on.

[0036] like Figure 1As shown, in one embodiment, the reverse polarity short-circuit protection circuit 10 further includes a fourth resistor R4. The first end of the fourth resistor R4 is connected to the abnormal state signal output terminal DO3 of the microcontroller, and the second end of the fourth resistor R4 is connected to the control terminal of the second electronic switch Q1. In this embodiment, when the microcontroller detects a short circuit fault in the circuit, the abnormal state signal output terminal DO3 of the microcontroller outputs a high-level signal, which is transmitted to the control terminal of the second electronic switch Q1 through the fourth resistor R4, thereby turning on the second electronic switch Q1 and thereby cutting off the conduction path of the first electronic switch MC1 and achieving short-circuit protection. The fourth resistor R4 acts as a voltage divider resistor, primarily regulating the voltage transmitted from the abnormal state signal output terminal DO3 of the microcontroller to the control terminal of the second electronic switch Q1, thereby ensuring stable signal transmission between the microcontroller and the second electronic switch Q1 and preventing damage to the second electronic switch Q1 that may be caused by excessive voltage.

[0037] like Figure 1 As shown, in one embodiment, the reverse polarity short-circuit protection circuit 10 further includes a fifth resistor R5. A first end of the fifth resistor R5 is connected to the first end of the first electronic switch MC1, and a second end of the fifth resistor R5 is grounded. In this embodiment, because the fifth resistor R5 is connected to the first electronic switch MC1, the fifth resistor R5 acts as a voltage divider for the first electronic switch MC1, thereby providing a stable bias voltage for the control terminal of the first electronic switch MC1. This prevents excessive voltage flowing to the control terminal of the first electronic switch MC1 and causing damage to the first electronic switch MC1, thereby ensuring normal operation of the first electronic switch MC1. Furthermore, the fifth resistor R5 also prevents electrostatic discharge in the circuit. Because the control terminal and the second end of the first electronic switch MC1 have a high impedance, even a small amount of static electricity will generate a high voltage between the control terminal and the second end of the first electronic switch MC1, which can easily cause malfunction of the first electronic switch MC1. In this case, the fifth resistor R5 acts as a rapid discharge path for the static electricity between the control terminal and the second end of the first electronic switch MC1, protecting the first electronic switch MC1 from static electricity damage.

[0038] like Figure 1As shown, in one embodiment, the reverse polarity short-circuit protection circuit 10 further includes a Zener diode Z6, the anode of which is connected to the control signal output terminal CM of the charger detection circuit, and the cathode of which is grounded. In this embodiment, when the voltage output by the charger detection circuit exceeds the breakdown voltage of the Zener diode Z6, the Zener diode Z6 quickly turns on, shunting the excess voltage to ground in the form of current, thereby effectively limiting the voltage at the signal output terminal of the charger detection circuit and protecting other components in the circuit from excessive voltage. Specifically, at the moment the charger is connected, if the output voltage of the charger detection circuit becomes unstable due to power supply fluctuations, the Zener diode Z6 can quickly respond and stabilize the output voltage, thereby ensuring that the control terminal of the first electronic switch tube MC1 is not damaged by excessive voltage.

[0039] like Figure 1 As shown, in one embodiment, the first electronic switch transistor MC1 is an N-channel MOS transistor. In this embodiment, the first terminal of the first electronic switch transistor MC1 serves as the drain of the N-channel MOS transistor, the second terminal of the first electronic switch transistor MC1 serves as the source of the N-channel MOS transistor, and the control terminal of the first electronic switch transistor MC1 serves as the gate of the N-channel MOS transistor. When the charger is properly connected, the signal output terminal of the charger detection circuit outputs a high-level signal, which is applied to the gate of the N-channel MOS transistor through the first resistor R1, causing its gate voltage to exceed the threshold voltage, thereby turning on the first electronic switch transistor MC1 and allowing current to flow from the positive electrode of the battery to the negative electrode, completing the charging process. When the charger is reversely connected, the signal output by the charger detection circuit becomes low, and the gate voltage of the N-channel MOS transistor decreases and falls below its threshold voltage, turning off the first electronic switch transistor MC1. Furthermore, because the parasitic reverse diode within the N-channel MOS transistor is unidirectional, it effectively blocks reverse current flow in the reverse connection condition, thereby protecting the battery from reverse current damage.

[0040] like Figure 1As shown, in one embodiment, the second electronic switch Q1 is an NPN transistor. In this embodiment, the first terminal of the second electronic switch Q1 serves as the collector of the NPN transistor, the second terminal of the second electronic switch Q1 serves as the emitter of the NPN transistor, and the control terminal of the second electronic switch Q1 serves as the base of the NPN transistor. When the circuit is in a normal charging state, the abnormal state signal output terminal DO3 of the microcontroller and the short-circuit signal output terminal of the operational amplifier maintain a low-level signal output, resulting in the base voltage of the second electronic switch Q1 being insufficient to drive it into conduction, and thus the second electronic switch Q1 is in an off state. When a short-circuit fault occurs in the circuit, the abnormal state signal output terminal DO3 of the microcontroller and the short-circuit signal output terminal of the operational amplifier respectively output high-level signals to the base of the second electronic switch tube Q1, so that the base voltage of the second electronic switch tube Q1 is greater than the threshold voltage required for its conduction. As a result, the second electronic switch tube Q1, after being turned on, connects the control terminal of the first electronic switch tube MC1 to the ground terminal to form a loop, thereby pulling the control terminal voltage of the first electronic switch tube MC1 to a low level, so that the first electronic switch tube MC1 is turned off, thereby cutting off the charging circuit and achieving short-circuit protection.

[0041] like Figure 1 As shown, in one embodiment, the first resistor is a current-limiting resistor, and the second resistor is a voltage-divider resistor. In this embodiment, the primary function of the first resistor R1 is to limit the current in the current loop to prevent excessive current from damaging components in the circuit, thereby ensuring circuit stability and safety. The second resistor R2, acting as a voltage-divider resistor, primarily forms a voltage-divider circuit with the third resistor R3 to regulate the voltage from the operational amplifier output terminal AD_CUR1 to the control terminal of the second electronic switch Q1. When the operational amplifier output terminal AD_CUR1 outputs a high-level signal, the voltage-dividering action of the second resistor R2 and the third resistor R3 ensures a stable voltage at the control terminal of the second electronic switch Q1, thereby increasing the voltage at the control terminal of the second electronic switch Q1 above its threshold voltage, causing it to conduct. The conduction state of the second electronic switch Q1 then regulates the voltage at the control terminal of the first electronic switch MC1, providing precise control of the switching state of the first electronic switch MC1.

[0042] like Figure 1As shown, in one embodiment, the resistance ratio of the second resistor R2 to the third resistor R3 is 0.303. In this embodiment, the output terminal AD_CUR1 of the operational amplifier outputs a 1.25V high-level signal to the second resistor R2. The signal then passes through the series voltage divider network formed by the second resistor R2 and the third resistor R3. Since the first end of the third resistor R3 is respectively connected to the second end of the second resistor R2 and the control terminal of the second electronic switch Q1, and the turn-on threshold voltage of the control terminal of the second electronic switch Q1 is 0.6V, when the voltage across the third resistor R3 is greater than 0.6V, the second electronic switch Q1 will be turned on. When the resistance ratio of the second resistor R2 to the third resistor R3 is 0.303, the voltage across the third resistor will be greater than 0.6V, thereby ensuring the normal operation of the second electronic switch Q1.

[0043] A battery management system includes a reverse polarity short-circuit protection circuit 10 as described above. In this embodiment, when the charger is properly connected, the control signal output terminal CM of the charger detection circuit outputs a high-level signal to the first resistor R1. The high-level signal is then transmitted to the control terminal of the first electronic switch MC1, causing the voltage at the control terminal of the first electronic switch MC1 to exceed its threshold voltage, turning on the first electronic switch MC1 and allowing current to flow from the positive electrode of the battery to the negative electrode, thereby allowing normal charging. Simultaneously, a microcontroller continuously monitors the current state in the circuit. During normal charging, the output terminal AD_CUR1 of the operational amplifier continuously outputs a low-level signal to the control terminal of the second electronic switch Q1, keeping it in the off state. When the charger is reverse polarity, the internal parasitic diode of the first electronic switch MC1 has unidirectional conductivity, thus preventing reverse current from damaging the battery. Furthermore, in the reverse polarity condition, the output signal of the control signal output terminal CM of the charger detection circuit becomes low-level, causing the voltage at the control terminal of the first electronic switch MC1 to fall below its threshold voltage, turning off the first electronic switch MC1 and further ensuring the effectiveness of the reverse polarity protection. When a short circuit occurs in an electrical loop, the current in the loop will increase dramatically. After the operational amplifier receives the abnormal short-circuit current signal, the level signal output by the output terminal AD_CUR1 of the operational amplifier will also increase. Since the output terminal AD_CUR1 of the operational amplifier is connected to the control terminal of the second electronic switch tube Q1, when the output voltage is greater than the threshold voltage of the control terminal of the second electronic switch tube Q1, the second electronic switch tube Q1 is turned on, and the control terminal of the first electronic switch tube MC1 is connected to the ground terminal through the second electronic switch tube Q1 to form a loop, thereby reducing the voltage at the control terminal of the first electronic switch tube MC1 to zero, thereby turning off the first electronic switch tube MC1 and disconnecting the charging circuit to achieve short-circuit protection. Specifically, when the microcontroller detects a short circuit, the abnormal state signal output terminal DO3 of the microcontroller will output a high-level signal to the control terminal of the second electronic switch tube Q1 to keep the control terminal voltage of the second electronic switch tube Q1 greater than its threshold voltage, thereby ensuring that the second electronic switch tube Q1 remains in the on state when a short circuit occurs in the circuit, and ensuring that the first electronic switch tube MC1 is in the off state, thereby improving the reliability of the short circuit protection of the anti-reverse short-circuit protection circuit 10.Furthermore, after the short-circuit fault is removed, the output level signal of the output terminal AD_CUR1 of the operational amplifier gradually decreases, causing the voltage at the control terminal of the second electronic switch tube Q1 to decrease to its threshold voltage, thereby turning off the second electronic switch tube Q1. The control terminal of the first electronic switch tube MC1 regains the high-level signal output by the control signal output terminal CM of the charger detection circuit, thereby automatically restoring the circuit to a normal charging state. At the same time, after the microcontroller detects that the short-circuit fault has been removed, the abnormal state signal output terminal DO3 of the microcontroller stops outputting a high-level signal to the control terminal of the second electronic switch tube Q1, thereby ensuring that the circuit can complete the self-recovery function.

[0044] Compared with the prior art, the present disclosure has at least the following advantages:

[0045] 1. When a short circuit occurs in the aforementioned reverse polarity short-circuit protection circuit 10, the operational amplifier output terminal AD_CUR1 outputs a high-level signal to the control terminal of the second electronic switch Q1, turning on the second electronic switch Q1. This in turn grounds the control terminal of the first electronic switch MC1, cutting off the battery charging circuit. Furthermore, after detecting a short circuit, the microcontroller's abnormal status signal output terminal also outputs a high-level signal to the control terminal of the second electronic switch Q1, keeping the second electronic switch Q1 in the on state. This provides a dual short-circuit protection mechanism and improves the reliability of the reverse polarity short-circuit protection circuit 10.

[0046] 2. On the other hand, since the internal parasitic diode of the first electronic switch tube MC1 has unidirectional conductivity, it can effectively prevent reverse current from damaging the battery when the charger is reversely connected. Therefore, the reverse connection short-circuit protection circuit 10 integrates reverse connection protection and short-circuit protection functions, thereby reducing the number of components and simplifying the circuit design, thereby reducing the cost of using the reverse connection short-circuit protection circuit 10.

[0047] 3. Furthermore, when the short-circuit fault is removed, the reverse polarity short-circuit protection circuit 10 can automatically recover to a normal charging state through the operational amplifier and the microcontroller, thereby reducing human intervention and further enhancing the continuous operation capability of the reverse polarity short-circuit protection circuit 10.

[0048] The above-described embodiments merely represent several implementation methods of the present disclosure. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the scope of the present disclosure, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the disclosed patent shall be determined by the appended claims.

Claims

1. A reverse connection short circuit protection circuit, characterized in that: It includes a first electronic switch tube, a second electronic switch tube, a first resistor, a second resistor and a third resistor; The control end of the first electronic switch tube is used to be connected to the control signal output end of the charger detection circuit, the first end of the first electronic switch tube is used to be connected to the output end of the charger detection circuit, the second end of the first electronic switch tube is used to be connected to the negative electrode of the battery, the first end of the second electronic switch tube is connected to the control end of the first electronic switch tube, the control end of the second electronic switch tube is used to be connected to the abnormal state signal output end of the microcontroller, the second end of the second electronic switch tube is grounded, the first end of the first resistor is used to be connected to the control signal output end of the charger detection circuit, the second end of the first resistor is connected to the control end of the first electronic switch tube, the first end of the second resistor is used to be connected to the output end of the operational amplifier, the second end of the second resistor is connected to the control end of the second electronic switch tube, the first end of the third resistor is respectively connected to the second end of the second resistor and the control end of the second electronic switch tube, and the second end of the third resistor is grounded.

2. The reverse connection short circuit protection circuit according to claim 1, characterized in that: The reverse connection short circuit protection circuit further includes a first capacitor, a first end of the first capacitor is connected to the control end of the second electronic switch tube, and a second end of the first capacitor is grounded.

3. The reverse connection short circuit protection circuit according to claim 1, characterized in that: The anti-reverse short-circuit protection circuit also includes a fourth resistor, a first end of the fourth resistor is connected to the abnormal state signal output end of the microcontroller, and a second end of the fourth resistor is connected to the control end of the second electronic switch tube.

4. The reverse connection short circuit protection circuit according to claim 1, characterized in that: The reverse connection short circuit protection circuit further includes a fifth resistor, a first end of the fifth resistor is connected to the first end of the first electronic switch tube, and a second end of the fifth resistor is grounded.

5. The reverse connection short circuit protection circuit according to claim 4, characterized in that: The reverse connection short circuit protection circuit further includes a voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the first end of the first electronic switch tube, and the anode of the voltage stabilizing diode is grounded.

6. The reverse connection short circuit protection circuit according to claim 1, characterized in that: The first electronic switch tube is an N-channel MOS tube.

7. The reverse connection short circuit protection circuit according to claim 1, characterized in that: The second electronic switch tube is an NPN transistor.

8. The reverse connection short circuit protection circuit according to claim 1, characterized in that: The first resistor is a current limiting resistor, and the second resistor is a voltage dividing resistor.

9. The reverse connection short circuit protection circuit according to claim 1, characterized in that: The resistance ratio of the second resistor to the third resistor is 0.

303.

10. A battery management system, characterized in that: The invention comprises the anti-reverse short-circuit protection circuit as described in any one of claims 1 to 9.

Images