Overvoltage protection devices for vehicle power supplies, vehicles and their overvoltage protection methods

Abstract

This invention discloses an overvoltage protection device for a vehicle power supply, a vehicle, and an overvoltage protection method thereof. The device includes: a comparison unit that samples the power supply voltage of the vehicle power supply and outputs a first-level signal when the power supply voltage is greater than or equal to a reference voltage and a second-level signal when the power supply voltage is less than the reference voltage; a delay unit that filters the first-level signal so that the first-level signal is allowed to be output when its duration is greater than or equal to a set delay time, thus obtaining a delayed output signal; and shuts off the output of the second-level signal; and an overvoltage protection unit that disconnects itself upon receiving the delayed output signal to disconnect the load power supply circuit of the vehicle power supply; and remains open when no delayed output signal is received, thus forming a load power supply circuit. This solution achieves overvoltage protection by detecting the power supply voltage of the vehicle power supply, ensuring that the vehicle control unit (VCU) is not damaged due to overvoltage of the vehicle power supply.

Description

Technical Field

[0001] This invention belongs to the field of automotive power supply technology, specifically relating to an overvoltage protection device for automotive power supply, a vehicle and its overvoltage protection method, and particularly to an overvoltage detection and protection circuit for automotive power supply, a vehicle and its overvoltage protection method. Background Technology

[0002] With the rapid development of technology, new energy vehicles are increasingly entering people's daily lives. Vehicle power supplies can be divided into high-voltage and low-voltage power supplies. The stability of the vehicle power supply is crucial for the reliable operation of the vehicle controller. Overvoltage in the vehicle power supply can cause varying degrees of damage to the controller, and in severe cases, render it inoperable. When the vehicle operates in harsh environments, the power supply voltage fluctuates significantly. Furthermore, since vehicle controllers, such as the vehicle control unit (VCU), are composed of various electronic components, which generate considerable electromagnetic interference during operation, the stability of the vehicle power supply becomes a critical prerequisite for the stable operation of the VCU.

[0003] Excessive voltage in the vehicle power supply (such as constant voltage) can damage the electronic components of the vehicle control unit (VCU) and cause irreversible damage to the copper insulation of the wiring. Furthermore, excessively high voltage can render the VCU inoperable, seriously threatening personal safety. Therefore, quickly and accurately detecting the vehicle power supply voltage to prevent damage to the VCU due to overvoltage and ensuring the stability of the vehicle power supply has become a key research issue.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide an overvoltage protection device for vehicle power supply, a vehicle, and an overvoltage protection method thereof, so as to solve the problem that excessive power supply voltage of vehicle power supply will cause the vehicle controller (VCU) to malfunction and seriously threaten personal safety. The invention achieves the effect of detecting the power supply voltage of vehicle power supply to realize overvoltage protection and ensure that the vehicle controller (VCU) is not damaged due to overvoltage of vehicle power supply.

[0006] This invention provides an overvoltage protection device for a vehicle power supply, comprising: a comparison unit, a delay unit, and an overvoltage protection unit. The comparison unit, the delay unit, and the overvoltage protection unit are sequentially disposed between the vehicle power supply and a load, and the overvoltage protection unit is located in the load power supply circuit between the vehicle power supply and the load. The comparison unit is configured to sample the power supply voltage of the vehicle power supply and compare the sampled power supply voltage with a reference voltage. It outputs a first-level signal when the power supply voltage is greater than or equal to the reference voltage, and outputs a second-level signal when the power supply voltage is less than the reference voltage. The delay unit is configured to, when the comparison unit outputs the first-level signal... In the case of a first-level signal, the duration of the first-level signal is filtered so that the first-level signal is allowed to be output if the duration of the first-level signal is greater than or equal to a set delay time, thus obtaining a delayed output signal; while in the case of the comparison unit outputting a second-level signal, the output of the second-level signal is turned off; the overvoltage protection unit is configured to disconnect itself when the delay unit outputs the delayed output signal, thereby disconnecting the load power supply circuit of the vehicle power supply and realizing overvoltage protection for the vehicle power supply; while in the case of no output signal from the comparison unit, the overvoltage protection unit is not disconnected, so that a load power supply circuit is formed between the vehicle power supply and the load of the vehicle power supply.

[0007] In some embodiments, the comparison unit includes: a sampling module, a reference voltage setting module, and a comparison module; wherein, the comparison unit samples the power supply voltage of the vehicle power supply and compares the sampled power supply voltage with a reference voltage to output a first level signal when the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and outputs a second level signal when the power supply voltage of the vehicle power supply is less than the reference voltage. This includes: the sampling module being configured to sample the bus voltage of the vehicle power supply to obtain the power supply voltage; the reference voltage setting module being configured to set the reference voltage using the bus voltage of the vehicle power supply to obtain the reference voltage; and the comparison module being configured to compare the sampled power supply voltage of the vehicle power supply with the reference voltage to output a first level signal when the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and output a second level signal when the power supply voltage of the vehicle power supply is less than the reference voltage.

[0008] In some embodiments, the sampling module includes: a first voltage divider module, a second voltage divider module, and a third voltage divider module; the reference voltage setting module includes: a first current limiting module and a first voltage regulating module; the comparison module includes: a comparator module; wherein, the bus voltage of the vehicle power supply is grounded after passing through the first voltage divider module, the second voltage divider module, and the third voltage divider module; the common terminal of the second voltage divider module and the third voltage divider module is connected to the non-inverting input terminal of the comparator module; the bus voltage of the vehicle power supply is also connected to the cathode of the first voltage regulating module after passing through the first current limiting module; the anode of the first voltage regulating module is grounded; the common terminal of the first current limiting module and the first voltage regulating module is connected to the inverting input terminal of the comparator module; the output terminal of the comparison module is connected to the delay unit to output the first level signal or the second level signal to the delay unit.

[0009] In some embodiments, the delay unit includes a delay time setting module and an output module; wherein, when the comparison unit outputs the first level signal, the delay unit filters the duration of the first level signal so that the first level signal is allowed to be output if the duration of the first level signal is greater than or equal to a set delay time, thereby obtaining a delayed output signal; and when the comparison unit outputs the second level signal, the delay unit shuts off the output of the second level signal, including: the delay time setting module is configured to set the delay time based on the first level signal or the second level signal output by the comparison unit. The first level signal or the second level signal is filtered according to the set delay time to filter out signals in the first level signal or the second level signal whose duration is less than the delay time; the output module is configured to turn on itself when the signal filtered by the delay time setting module is a first level signal, so as to allow the output of the first level signal filtered by the delay time setting module to obtain a delayed output signal; and to turn off itself when the signal filtered by the delay time setting module is a second level signal, so as to turn off the output of the second level signal filtered by the delay time setting module.

[0010] In some embodiments, the delay time setting module includes a charging resistor module and a charging capacitor module; the output module includes a second voltage regulator module; wherein, the output terminal of the comparison unit, after passing through the charging resistor module, is grounded via the charging capacitor module and connected to the cathode of the second voltage regulator module; the anode of the second voltage regulator module serves as the output terminal of the delay unit and is connected to the overvoltage protection unit; when the signal filtered by the delay time setting module is a first-level signal, when the charging voltage of the charging capacitor module is greater than the reverse voltage of the second voltage regulator module, the second voltage regulator module is turned on to allow the first-level signal filtered by the delay time setting module to be output, thus obtaining a delayed output signal; when the signal filtered by the delay time setting module is a second-level signal, when the charging voltage of the charging capacitor module is less than the reverse voltage of the second voltage regulator module, the second voltage regulator module is turned off to shut off the second-level signal output filtered by the delay time setting module.

[0011] In some embodiments, the delay unit further includes an isolation module; wherein the isolation module is disposed on the output side of the output module and is configured to isolate and protect the delayed output signal output by the output module before outputting it.

[0012] In some embodiments, the overvoltage protection unit includes: a voltage follower module, a control module, and a switching module; the overvoltage protection unit disconnects itself when the delay unit outputs the delayed output signal, thereby disconnecting the load power supply circuit of the vehicle power supply and achieving overvoltage protection for the vehicle power supply; and when the comparison unit has no output signal, the overvoltage protection unit does not disconnect itself, so that a load power supply circuit is formed between the vehicle power supply and the load of the vehicle power supply, including: the voltage follower module is configured to, when the delay unit outputs the delayed output signal, disconnect the delay unit... The output delayed signal abruptly increases to obtain a drive signal; the control module is configured to turn on itself based on the drive signal output by the voltage follower module to output a control signal; the switch module is configured to turn off itself based on the control signal output by the control module to disconnect the load power supply circuit of the vehicle power supply and realize overvoltage protection for the vehicle power supply; when the comparison unit has no output signal, the control module cannot output a control signal, so that the switch module does not turn off itself, so that a load power supply circuit is formed between the vehicle power supply and the load of the vehicle power supply.

[0013] In some embodiments, the overvoltage protection unit further includes an overvoltage indicator module; the overvoltage indicator module is disposed between the output terminal of the voltage follower module and ground, and is configured to activate the overvoltage indicator module to issue an indicator signal when the voltage follower module outputs the drive signal, so as to remind the user that the vehicle power supply has an overvoltage fault.

[0014] In some embodiments, the voltage follower module includes: a voltage follower; the control module includes: an input resistor module, a transistor module, and an output resistor module; the switching module includes: a fourth voltage divider module, a fifth voltage divider module, and a MOSFET module; wherein, the delayed output signal output from the output terminal of the delay unit is input to the non-inverting input terminal of the voltage follower; the output terminal of the voltage follower is connected to the base of the transistor module via the input resistor module; the collector of the transistor module is connected to the gate of the MOSFET module via the output resistor module; the emitter of the transistor module is grounded; the fifth and sixth voltage divider resistor modules are connected in series between the vehicle power supply and ground; the common terminal of the fifth and sixth voltage divider resistor modules is connected to the gate of the MOSFET module; The source of the MOSFET module is grounded, and the drain of the MOSFET module is connected to the load. When the delay unit outputs the delay output signal, the voltage follower causes the delay output signal output by the delay unit to suddenly increase, thereby obtaining a drive signal. The drive signal turns on the transistor module, and when the transistor module is on, the gate of the MOSFET module is pulled low, causing the MOSFET module to turn off. When the delay unit does not output the delay output signal, the voltage follower cannot output the drive signal, and the transistor module is turned off without the drive signal. When the transistor module is off, the gate of the MOSFET module is turned on based on the voltage division of the fifth and sixth voltage divider modules, thus forming a load power supply loop between the vehicle power supply and the load.

[0015] In conjunction with the above-described device, the present invention further provides a vehicle, including: the overvoltage protection device for the vehicle power supply described above.

[0016] In conjunction with the aforementioned vehicle, the present invention further provides an overvoltage protection method for a vehicle, comprising: sampling the power supply voltage of the vehicle power supply through the comparison unit, and comparing the sampled power supply voltage of the vehicle power supply with a reference voltage, so as to output a first level signal when the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and output a second level signal when the power supply voltage of the vehicle power supply is less than the reference voltage; and filtering the duration of the first level signal when the comparison unit outputs the first level signal through the delay unit, so as to filter the duration of the first level signal during its duration. When the delay time is greater than or equal to the set delay time, the first level signal is allowed to be output to obtain a delayed output signal; when the comparison unit outputs the second level signal, the output of the second level signal is turned off; through the overvoltage protection unit, when the delay unit outputs the delayed output signal, the overvoltage protection unit itself is disconnected to disconnect the load power supply circuit of the vehicle power supply, thereby realizing overvoltage protection for the vehicle power supply; when the comparison unit has no output signal, the overvoltage protection unit itself is not disconnected, so that a load power supply circuit is formed between the vehicle power supply and the load of the vehicle power supply.

[0017] Therefore, the solution of the present invention, by setting up an overvoltage protection device for the vehicle power supply consisting of a comparison unit (such as a comparison circuit), a delay unit (such as a delay circuit), and an overvoltage protection unit (such as an overvoltage protection circuit), can detect and compare the power supply voltage of the vehicle power supply. When it is determined that the power supply voltage of the vehicle power supply is overvoltage, the load can be cut off in time to protect the vehicle controller VCU from damage by overvoltage. Thus, by detecting the power supply voltage of the vehicle power supply, overvoltage protection is achieved, ensuring that the vehicle controller VCU is not damaged due to overvoltage of the vehicle power supply, and also helps to improve the power supply stability of the vehicle power supply.

[0018] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an embodiment of the overvoltage protection device for vehicle power supply of the present invention;

[0021] Figure 2 A schematic diagram of an embodiment of a high-voltage detection and protection circuit for automotive power supplies;

[0022] Figure 3 A schematic diagram of an overvoltage detection and protection process for an embodiment of a high-voltage detection and protection circuit for automotive power supplies;

[0023] Figure 4 This is a schematic flowchart of an embodiment of the overpressure protection method for vehicles according to the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0025] Vehicle power supplies, serving as the power supply system for vehicles (such as new energy buses), are divided into power battery pack power supply and storage battery power supply. Power battery pack power supply uses high-voltage electricity, typically several hundred volts, while storage battery power supply uses low-voltage electricity, typically tens of volts. Accurate and rapid detection of over- and under-voltage conditions on the vehicle power supply bus is crucial for the stable operation of the entire vehicle.

[0026] The stability of the vehicle power supply significantly impacts the reliable operation of the vehicle control unit (VCU). Overvoltage in the vehicle power supply can cause varying degrees of damage to the VCU, and in severe cases, render the VCU malfunctioning and the vehicle unable to operate. This invention proposes an overvoltage protection device for the vehicle power supply. Specifically, it is a simple, fast-responding, low-cost, and reliable high-voltage detection and protection circuit for the vehicle power supply. This circuit can detect whether the vehicle power supply voltage is overvoltage, and when an overvoltage occurs, it can disconnect the load, protecting the VCU from overvoltage damage and significantly improving the power supply stability.

[0027] According to an embodiment of the present invention, an overvoltage protection device for a vehicle power supply is provided. See also... Figure 1 The diagram shows a structural schematic of an embodiment of the device of the present invention. The overvoltage protection device for the vehicle power supply may include: a comparison unit, a delay unit, and an overvoltage protection unit. The comparison unit, the delay unit, and the overvoltage protection unit are sequentially disposed between the vehicle power supply and the load, and the overvoltage protection unit is located in the load power supply circuit between the vehicle power supply and the load. Specifically, Figure 2This is a schematic diagram of an embodiment of a high-voltage detection and protection circuit for a vehicle power supply. The overvoltage and undervoltage detection and protection circuit accurately and quickly detects overvoltage and undervoltage conditions on the bus voltage of the vehicle power supply. Figure 2 As shown. Figure 2 As shown, the entire circuit of the high voltage detection and protection circuit of the vehicle power supply can be divided into three parts: a comparator circuit, a delay circuit, and an overvoltage protection circuit. The comparator circuit, the delay circuit, and the overvoltage protection circuit are arranged sequentially between the vehicle power supply and the load.

[0028] The comparison unit is configured to sample the power supply voltage (e.g., constant voltage) of the vehicle power supply and compare the sampled power supply voltage with a reference voltage. It outputs a first-level signal (e.g., a high-level signal) when the power supply voltage is greater than or equal to the reference voltage, and outputs a second-level signal (e.g., a low-level signal) when the power supply voltage is less than the reference voltage. Specifically, as... Figure 2 The comparison circuit shown is used to detect the power supply voltage signal of the vehicle power supply, specifically, it detects the amplitude of the vehicle power supply voltage. Then, by comparing the detected amplitude of the vehicle power supply voltage with a reference voltage, it determines whether there is an overvoltage, thereby driving the overvoltage protection circuit to activate, ensuring that the overvoltage protection circuit only activates when there is an overvoltage. Here, undervoltage protection can be implemented when the voltage is too low by setting a threshold and then configuring resistor R9 and resistor R... GS The resistance value prevents the MOSFET Q3 from being driven when the voltage drops to a certain value, causing the loop to automatically disconnect.

[0029] In some embodiments, the comparison unit includes: a sampling module, a reference voltage setting module, and a comparison module.

[0030] The comparison unit samples the power supply voltage (e.g., constant voltage) of the vehicle power supply and compares the sampled power supply voltage with a reference voltage. It outputs a first-level signal (e.g., a high-level signal) when the power supply voltage is greater than or equal to the reference voltage, and outputs a second-level signal (e.g., a low-level signal) when the power supply voltage is less than the reference voltage. This includes:

[0031] The sampling module is configured to sample the bus voltage of the vehicle power supply, such as sampling the constant voltage of the vehicle power supply, to obtain the power supply voltage of the vehicle power supply. Preferably, the sampling module includes: a first voltage divider module, a second voltage divider module, and a third voltage divider module, wherein the first voltage divider module is such as resistor R1, the second voltage divider module is such as resistor R2, and the third voltage divider module is such as resistor R3.

[0032] The reference voltage setting module is configured to set a reference voltage using the bus voltage of the vehicle power supply to obtain the reference voltage. Preferably, the reference voltage setting module includes: a first current limiting module and a first voltage regulating module, wherein the first current limiting module is such as a resistor R4 and the first voltage regulating module is such as a Zener diode D1.

[0033] The comparison module is configured to compare the sampled power supply voltage of the vehicle power supply with a reference voltage, and to output a first level signal (e.g., a high level signal) when the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and to output a second level signal (e.g., a low level signal) when the power supply voltage of the vehicle power supply is less than the reference voltage. Preferably, the comparison module includes a comparator module, such as comparator A.

[0034] The bus voltage of the vehicle power supply is grounded after passing through the first voltage divider module, the second voltage divider module, and the third voltage divider module. The common terminal of the second voltage divider module and the third voltage divider module is connected to the non-inverting input terminal of the comparator module. The bus voltage of the vehicle power supply is also connected to the cathode of the first voltage regulator module after passing through the first current limiting module. The anode of the first voltage regulator module is grounded. The common terminal of the first current limiting module and the first voltage regulator module is connected to the inverting input terminal of the comparator module. The output terminal of the comparator module is connected to the delay unit to output either the first level signal or the second level signal to the delay unit.

[0035] Specifically, see Figure 2 The example circuit shown includes resistors R1, R2, R3, and R4, a Zener diode D1, and comparator A. Voltage P is grounded to GND via resistors R1, R2, and R3. Voltage P is also connected to the cathode of Zener diode D1 via resistor R4, and the anode of Zener diode D1 is grounded to GND. Voltage P is further connected to the output reference voltage V via resistor R4. F The signal is fed to the inverting input of comparator A. The common terminal of resistors R2 and R3 outputs the detected automotive power supply voltage signal to the non-inverting input of comparator A. The power supply terminal of comparator A is connected to the DC power supply VCC, and the ground terminal of comparator A is grounded to GND. The output of comparator A is connected to a delay circuit.

[0036] The system uses three resistors (R1, R2, and R3) to divide the voltage. This allows for more precise voltage division and improves reliability, as shorting any one of these resistors will not burn out the comparator. The reference voltage is provided by the bus voltage through regulation. This differs from the voltage conversion from the load voltage at the back end, allowing the comparator to start operating instantly upon power-up on the bus, thus enabling immediate overvoltage protection with a fast response. It also allows for separation of the load and the protection circuit. In the event of an overvoltage, MOSFET Q3 disconnects, protecting the load. During this time, the protection circuit indicator light remains on. When the bus voltage returns to normal, transistor Q2 turns off, MOSFET Q3 turns on, and the load resumes operation. Alternatively, the VCC of comparator A can be set to be supplied by the bus voltage through a voltage divider resistor and a Zener diode.

[0037] The delay unit is configured to, when the comparison unit outputs the first level signal, filter the duration of the first level signal so that if the duration of the first level signal is greater than or equal to a set delay time, the first level signal is allowed to be output, resulting in a delayed output signal; and when the comparison unit outputs the second level signal, the output of the second level signal is turned off. Specifically, as follows... Figure 2 The delay circuit shown is used to filter interference signals, specifically to filter out interference signals with a duration shorter than the configured delay time. The delay circuit can be configured according to actual needs to obtain an accurate overvoltage signal.

[0038] In some implementations, the delay unit includes a delay time setting module and an output module.

[0039] The delay unit, when the comparison unit outputs the first level signal, filters the duration of the first level signal so that if the duration of the first level signal is greater than or equal to a set delay time, the first level signal is allowed to be output, thus obtaining a delayed output signal; and when the comparison unit outputs the second level signal, it shuts off the output of the second level signal, including:

[0040] The delay time setting module is configured to set a delay time based on the first level signal or the second level signal output by the comparison unit, and to filter the first level signal or the second level signal according to the set delay time, so as to filter out signals in the first level signal or the second level signal whose duration is less than the delay time. Preferably, the delay time setting module includes: a charging resistor module and a charging capacitor module, wherein the charging resistor module is such as resistor R5 and the charging capacitor module is such as capacitor C1.

[0041] The output module is configured to turn on when the signal filtered by the delay time setting module is a first-level signal, allowing the first-level signal filtered by the delay time setting module to be output, thus obtaining a delayed output signal; and to turn off when the signal filtered by the delay time setting module is a second-level signal, thus shutting off the output of the second-level signal filtered by the delay time setting module. Preferably, the output module includes a second voltage regulator module, such as a Zener diode D2.

[0042] The output of the comparison unit, after passing through the charging resistor module, is grounded via the charging capacitor module and connected to the cathode of the second voltage regulator module. The anode of the second voltage regulator module serves as the output of the delay unit and is connected to the overvoltage protection unit. When the signal filtered by the delay time setting module is a first-level signal, and the charging voltage of the charging capacitor module is greater than the reverse voltage of the second voltage regulator module, the second voltage regulator module is turned on to allow the output of the first-level signal filtered by the delay time setting module, thus obtaining a delayed output signal. When the signal filtered by the delay time setting module is a second-level signal, and the charging voltage of the charging capacitor module is less than the reverse voltage of the second voltage regulator module, the second voltage regulator module is turned off to shut off the output of the second-level signal filtered by the delay time setting module.

[0043] Specifically, see Figure 2 The example shown, the delay circuit, includes: resistor R5, capacitor C1, and Zener diode D2. The output of comparator A in the comparator circuit, after passing through resistor R5, is connected to the cathode of Zener diode D2 on one hand, and to ground (GND) on the other hand through capacitor C1. The anode of Zener diode D2 is connected to the overvoltage protection circuit to prevent false turn-on and avoid spurious overvoltage. When no overvoltage occurs in the high-voltage detection and protection circuit of the vehicle power supply, the comparator circuit outputs a low level, preventing the Zener diode from turning on. When a spurious overvoltage occurs in the high-voltage detection and protection circuit of the vehicle power supply, capacitor C1 does not charge to the Zener diode D2's forward voltage drop, preventing the transistor Q2 from turning on. Only when the overvoltage exceeds the delay time will the protection circuit disconnect the load.

[0044] Preferably, the delay unit further includes: an isolation module, such as an optocoupler U1 and a resistor R. 10 and resistance R 11 An isolation module is constructed; wherein, the isolation module is disposed on the output side of the output module and is configured to isolate and protect the delayed output signal output by the output module before outputting it, thereby increasing security. Specifically, in Figure 2In the example shown, adding optocoupler U1 allows it to turn on when capacitor C1 charges to the Zener diode D2's forward voltage of 1.3V. At this point, voltage follower A1 outputs a high-level signal to drive transistor Q2. The advantage of adding optocoupler U1 is that it prevents high-voltage surges at the bus input from damaging the downstream overvoltage protection circuit. Furthermore, the fact that the input to the non-inverting terminal of voltage follower A1 is obtained by voltage division from the bus voltage improves its driving capability.

[0045] The overvoltage protection unit is configured to disconnect itself when the delay unit outputs the delayed output signal, thereby disconnecting the load power supply circuit of the vehicle power supply and achieving overvoltage protection for the vehicle power supply. However, when the comparator has no output signal (i.e., when the comparator does not output the second level signal), the overvoltage protection unit is not disconnected, ensuring that a load power supply circuit is formed between the vehicle power supply and its load. Specifically, as... Figure 2 The overvoltage protection circuit shown is used to protect the normal operation of the vehicle control unit (VCU) based on the overvoltage signal filtered by the delay circuit.

[0046] The high-voltage detection and protection circuit for vehicle power supplies provided by this invention detects the bus voltage of the vehicle power supply in real time. When the power supply voltage is overvoltage, it shuts down the MOSFET (such as MOSFET Q3) to disconnect the load circuit, thus providing real-time overvoltage protection for the vehicle controller (VCU). This effectively prevents damage to the VCU caused by excessively high power supply voltage. The circuit can restart and operate normally when the power supply voltage is normal, without requiring component replacement. It is convenient to use and has a simple control method.

[0047] In some implementations, the overvoltage protection unit includes: a voltage follower module, a control module, and a switching module.

[0048] The overvoltage protection unit, when the delay unit outputs the delayed output signal, disconnects itself to break the load power supply circuit of the vehicle power supply, thereby achieving overvoltage protection for the vehicle power supply. Conversely, when the comparison unit has no output signal (i.e., when the comparison unit does not output the second level signal), the overvoltage protection unit remains open, ensuring that a load power supply circuit is formed between the vehicle power supply and its load, including:

[0049] The voltage follower module is configured to cause a sudden increase in the delayed output signal output by the delayed unit when the delayed unit outputs the delayed output signal, thereby obtaining a drive signal. Preferably, the voltage follower module includes a voltage follower, such as a voltage follower A1 and its peripheral circuitry.

[0050] The control module is configured to turn itself on based on the drive signal output by the voltage follower module, so as to output a control signal. Preferably, the control module includes: an input resistor module, a transistor module, and an output resistor module, wherein the input resistor module is such as resistor R7, the transistor module is such as transistor Q2, and the output resistor module is such as resistor R... c .

[0051] The switching module is configured to turn off itself based on the control signal output by the control module, thereby disconnecting the load power supply circuit of the vehicle power supply and achieving overvoltage protection for the vehicle power supply. When the comparator unit has no output signal (i.e., when the comparator unit does not output the second level signal), the control module cannot output a control signal to prevent the switching module from turning off, thus ensuring that a load power supply circuit is formed between the vehicle power supply and its load. Preferably, the switching module includes: a fourth voltage divider module, a fifth voltage divider module, and a MOSFET module, wherein the fourth voltage divider module is such as resistor R9, and the fifth voltage divider module is such as resistor R... GS And MOSFET modules such as MOSFET Q3.

[0052] The delayed output signal output from the delay unit is input to the non-inverting input of the voltage follower. The output of the voltage follower, after passing through the input resistor module, is connected to the base of the transistor module. The collector of the transistor module, after passing through the output resistor module, is connected to the gate of the MOSFET module. The emitter of the transistor module is grounded. The fifth and sixth voltage divider resistor modules are connected in series between the vehicle power supply and ground. The common terminal of the fifth and sixth voltage divider resistor modules is connected to the gate of the MOSFET module. The source of the MOSFET module is grounded, and the drain of the MOSFET module is connected to the load. When the delay unit outputs the delayed output signal, the voltage follower causes the delayed output signal output by the delay unit to abruptly increase, thereby obtaining a drive signal. The drive signal turns on the transistor module, and when the transistor module is on, the gate of the MOSFET module is pulled low, thus turning off the MOSFET module. Specifically, due to the resistor R... c The resistance is much smaller than the resistor R. GS And resistance R cSince the resistance value is less than that of resistor R9, when the transistor module is on, the gate of the MOSFET module is pulled low, causing the MOSFET module to turn off. When the delay unit does not output the delay output signal, the voltage follower cannot output the drive signal, and the transistor module is turned off without the drive signal. When the transistor module is off, the gate of the MOSFET module is turned on based on the voltage division of the fifth and sixth voltage divider modules, thus forming a load power supply loop between the vehicle power supply and the load.

[0053] In some embodiments, the overvoltage protection unit further includes an overvoltage indicator module, such as a light-emitting diode (LED1). The overvoltage indicator module is disposed between the output terminal of the voltage follower module and ground, and is configured to activate and issue an indicator signal when the voltage follower module outputs the drive signal, thereby alerting the user to an overvoltage fault in the vehicle power supply. See also... Figure 2 In the example shown, LED1 serves as an overvoltage indicator.

[0054] Specifically, see Figure 2 The example shown is an overvoltage protection circuit, including: resistors R6, R7, R8, R9, and R... c Resistance R GS The components include capacitor C2, voltage follower A1, LED1, transistor Q2, and MOSFET Q3. Using voltage follower A1 improves the driving capability. Using a combination of transistor Q2 and MOSFET Q3 for overvoltage shutdown and normal conduction reduces the number of components used, lowers costs, increases reliability, and simplifies control logic.

[0055] In the delay circuit, the anode of the Zener diode D2 is connected to the input terminal of the optocoupler U1. The inverting input terminal of the voltage follower A1 is connected to its output terminal via a parallel capacitor C2 and resistor R6. The output terminal of the voltage follower A1 is connected to the anode of the LED1 via resistor R8, and the cathode of the LED1 is grounded. The output terminal of the voltage follower A1 is also connected to the base of the transistor Q2 via resistor R7. The emitter of the transistor Q2 is grounded to GND, and resistors R9 and R... GS The transistor Q2 is connected in series between voltage P and ground GND. The collector of transistor Q2 is connected to resistor R. c Then connected to resistor R9 and resistor R GS The common terminal. Resistors R9 and R GS The common terminal is connected to the gate of MOSFET Q3. The source of MOSFET Q3 is grounded to GND. And capacitor C C As a bus capacitor, the drain of MOSFET Q3 is connected to capacitor C.C One end of the capacitor C C The other end is connected to voltage P. Capacitor C C Capable of outputting load voltage U o Load voltage U o Used to supply power to the load.

[0056] Figure 3 A schematic diagram illustrating the overvoltage detection and protection process of an embodiment of a high-voltage detection and protection circuit for automotive power supplies. See also... Figure 2 and Figure 3 In the example shown, voltage P serves as the operating voltage for the comparator circuit, delay circuit, and overvoltage protection circuit. Voltage P is the input voltage of the vehicle controller VCU, such as 12V. Voltage P is divided by resistors R1, R2, and R3, and the divided voltage signal (i.e., the power supply voltage signal at the common terminal of resistors R2 and R3) is connected to the non-inverting input of comparator A. The inverting input of comparator A uses a Zener diode (i.e., Zener diode D1) to stabilize the voltage to the reference voltage V. F When the voltage at the non-inverting input of comparator A is higher than the voltage at the inverting input, comparator A outputs a high-level signal; otherwise, it outputs a low-level signal. The control signal output by comparator A is filtered by a delay circuit and then charges capacitor C1 through resistor R5. By controlling the charging time, interference signals with a time shorter than the charging time are filtered out, ensuring that only the valid drive signal (i.e., the control signal output by comparator A) can pass through normally. The charging time t is the delay time, which can be calculated by formula (1). Setting a reasonable delay time can filter out high-frequency interference signals.

[0057]

[0058] Where V1 is the power supply voltage, V0 is the initial voltage of capacitor C1, and V t Let be the voltage at time t during the charging of capacitor C1. R is the resistance of resistor R5, and C is the capacitance of capacitor C1.

[0059] When the charging voltage of capacitor C1 exceeds the reverse voltage of Zener diode D2, Zener diode D2 conducts, and the high-level signal output from the delay circuit is input to the non-inverting terminal of voltage follower A1. The output signal V of voltage follower A1... A1 The signal changes abruptly from low to high, driving transistor Q2 to conduct. Due to the resistance R... c The resistance is much smaller than that of resistor R. GS The resistance value, and the resistance R cThe resistance of R2 is less than that of R9, so the gate drive signal of MOSFET Q3 is a low-level signal, causing MOSFET Q3 to turn off. At this time, the high-voltage detection and protection circuit of the automotive power supply is overvoltage. Since the high-voltage detection and protection circuit of the automotive power supply cannot form a loop after MOSFET Q3 is turned off, no current flows through the analog load at the downstream end of the high-voltage detection and protection circuit of the automotive power supply, thus protecting the automotive power supply. Specifically, when the circuit does not experience overvoltage, transistor Q2 cannot conduct, and at this time, resistor R... c It has no effect; MOSFET Q3 is controlled by resistor R. GS With resistor R9, voltage is divided for power supply. GS A resistance value greater than R9 allows the gate of the MOSFET Q3 drive pin to be in a higher voltage state. When an overvoltage occurs in the circuit, transistor Q2 conducts, and resistor R... c Grounded via transistor Q2, due to resistor R c Much smaller than resistance R GS Most of the current flows through resistor R. c This is equivalent to changing the resistance R GS Short-circuited, and because of resistor R c It is less than the resistance R9, so the resistance R c The voltage divider is extremely small, meaning that the gate voltage of MOSFET Q3 is extremely small, almost at a low level, and cannot be turned on, thus disconnecting the circuit.

[0060] The following is a specific example to illustrate this solution:

[0061] Assuming voltage P is 12V, R1 = 500Ω, R2 = 500Ω, R3 = 3KΩ, R4 = 10KΩ, R5 = 40KΩ, C1 = 100uF, V F =12V. At this time, the voltage P is divided by the voltage divider resistors (i.e., resistors R1, R2, and R3), making the voltage at the non-inverting input of comparator A 9V. The voltage at the non-inverting input of comparator A is less than the voltage at the inverting input of comparator A. At this time, comparator A outputs a low-level signal. Due to the effect of the Zener diode D2 in the delay circuit, the low-level signal output by comparator A cannot drive the Zener diode D2 to conduct, the optocoupler U1 cannot be driven, the transistor Q2 cannot conduct, and consequently, the transistor Q3 cannot be driven to turn off. The power supply circuit of the vehicle power supply works normally.

[0062] Assuming voltage P ≥ 16V, R1 = 500Ω, R2 = 500Ω, R3 = 3KΩ, R4 = 10KΩ, R5 = 40KΩ, C1 = 100uF, V F=12V, the forward voltage of Zener diode D2 is 1.3V. At this time, the voltage P is divided by the voltage divider resistors (i.e., resistors R1, R2, and R3) so that the voltage at the non-inverting terminal of comparator A is ≥12V and the voltage at the non-inverting terminal of comparator A is ≥12V. At this time, comparator A outputs a high-level signal. The high-level signal output by comparator A charges capacitor C1 through the current-limiting resistor R5. The charging time t can be calculated from formula (1) as approximately 0.72S. When the charging voltage of capacitor C1 is greater than the forward voltage of Zener diode D2 (1.3V), Zener diode D2 conducts, thereby driving optocoupler U1 to conduct. At this time, voltage follower A1 outputs a high-voltage control signal to drive transistor Q2 to conduct, thereby driving MOSFET Q3 to disconnect. At this time, the power supply circuit of the vehicle power supply is open to avoid damage to the electronic components of the vehicle controller VCU due to excessively high input voltage (such as voltage P).

[0063] As can be seen from the example above, only voltage P signals with an amplitude greater than 16V and a duration greater than 0.72S can pass through the high-voltage detection and protection circuit of the vehicle power supply to achieve protection. Voltage signals with a amplitude and duration lower than this cannot pass through the high-voltage detection and protection circuit of the vehicle power supply to achieve protection, thus ensuring the reliable operation of the load circuit.

[0064] The high-voltage detection and protection circuit for vehicle power supplies provided by this invention can quickly, reliably, and in real-time detect whether the power supply voltage of the vehicle power supply is overvoltage. It can filter out interference signals on the power supply line of the vehicle power supply and can shut down the MOSFET (such as MOSFET Q3) to disconnect the load circuit when the power supply voltage of the vehicle power supply is overvoltage. This protects the downstream load of the vehicle power supply from damage due to the overvoltage of the vehicle power supply and effectively prevents the vehicle controller VCU from being damaged by the excessively high power supply voltage. It also greatly improves the power stability of the vehicle power supply.

[0065] The overcurrent protection circuit in the relevant scheme detects the voltage difference across the sampling resistor (the voltage difference on a bus), while the overvoltage protection circuit in this invention samples the voltage difference between the positive terminal of the bus and ground. For example, when a component in the circuit fails or is short-circuited, the current in the circuit will change, and the voltage difference across the sampling resistor will also change. However, this does not indicate a change in the voltage on the bus, so an overvoltage conclusion cannot be drawn.

[0066] By employing the technical solution of this invention, an overvoltage protection device for the vehicle power supply, consisting of a comparison unit (such as a comparison circuit), a delay unit (such as a delay circuit), and an overvoltage protection unit (such as an overvoltage protection circuit), can detect and compare the power supply voltage of the vehicle power supply. When it is determined that the power supply voltage of the vehicle power supply is overvoltage, the load can be cut off in time to protect the vehicle controller (VCU) from damage by overvoltage. Thus, by detecting the power supply voltage of the vehicle power supply, overvoltage protection is achieved, ensuring that the vehicle controller (VCU) is not damaged due to overvoltage of the vehicle power supply, and also improving the power supply stability of the vehicle power supply.

[0067] According to an embodiment of the present invention, a vehicle corresponding to an overvoltage protection device for an automotive power supply is also provided. The vehicle may include the overvoltage protection device for the automotive power supply described above.

[0068] Since the processing and functions implemented by the vehicle in this embodiment are basically the same as those in the embodiments, principles and examples of the device, any details not covered in this embodiment can be found in the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0069] By adopting the technical solution of the present invention, an overvoltage protection device for vehicle power supply is provided, consisting of a comparison unit (such as a comparison circuit), a delay unit (such as a delay circuit), and an overvoltage protection unit (such as an overvoltage protection circuit). This device can detect and compare the power supply voltage of the vehicle power supply, and promptly disconnect the load when it is determined that the power supply voltage of the vehicle power supply is overvoltage, so as to protect the vehicle controller VCU from damage by overvoltage. This protects the vehicle controller VCU and also helps to ensure the power supply stability of the vehicle power supply.

[0070] According to embodiments of the present invention, an overvoltage protection method for a vehicle is also provided, such as... Figure 4 The diagram shows a flowchart of an embodiment of the method of the present invention. The overvoltage protection method for a vehicle may include: installing the aforementioned overvoltage protection device for the vehicle's power supply between the vehicle's power supply and the load, to perform the following steps S110 to S130, thereby achieving overvoltage protection for the vehicle.

[0071] In step S110, the comparison unit samples the power supply voltage (e.g., constant voltage) of the vehicle power supply and compares the sampled power supply voltage with a reference voltage. A first level signal (e.g., high level signal) is output when the power supply voltage is greater than or equal to the reference voltage, and a second level signal (e.g., low level signal) is output when the power supply voltage is less than the reference voltage. Specifically, as... Figure 2The comparison circuit shown is used to detect the power supply voltage signal of the vehicle power supply. Specifically, it detects the power supply voltage amplitude of the vehicle power supply. Then, by comparing the detected power supply voltage amplitude of the vehicle power supply with the reference voltage, it determines whether there is an overvoltage and drives the overvoltage protection circuit to operate, ensuring that the overvoltage protection circuit only operates when there is an overvoltage.

[0072] In step S120, the delay unit filters the duration of the first level signal when the comparison unit outputs the first level signal, allowing the first level signal to be output if its duration is greater than or equal to a set delay time, thus obtaining a delayed output signal; conversely, when the comparison unit outputs the second level signal, the output of the second level signal is turned off. Specifically, as... Figure 2 The delay circuit shown is used to filter interference signals, specifically to filter out interference signals with a duration shorter than the configured delay time. The delay circuit can be configured according to actual needs to obtain an accurate overvoltage signal.

[0073] In step S130, the overvoltage protection unit disconnects itself when the delay unit outputs the delayed output signal, thereby disconnecting the load power supply circuit of the vehicle power supply and achieving overvoltage protection for the vehicle power supply. Conversely, when the comparison unit has no output signal (i.e., when the comparison unit does not output the second level signal), the overvoltage protection unit does not disconnect itself, ensuring that a load power supply circuit is formed between the vehicle power supply and its load. Specifically, as... Figure 2 The overvoltage protection circuit shown is used to protect the normal operation of the vehicle control unit (VCU) based on the overvoltage signal filtered by the delay circuit.

[0074] The high-voltage detection and protection circuit for vehicle power supplies provided by this invention detects the bus voltage of the vehicle power supply in real time. When the power supply voltage is overvoltage, it shuts down the MOSFET (such as MOSFET Q3) to disconnect the load circuit, thus providing real-time overvoltage protection for the vehicle controller (VCU). This effectively prevents damage to the VCU caused by excessively high power supply voltage. The circuit can restart and operate normally when the power supply voltage is normal, without requiring component replacement. It is convenient to use and has a simple control method.

[0075] Since the processing and functions implemented by the method in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned vehicles, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0076] By adopting the technical solution of this embodiment, an overvoltage protection device for the vehicle power supply, consisting of a comparison unit (such as a comparison circuit), a delay unit (such as a delay circuit), and an overvoltage protection unit (such as an overvoltage protection circuit), can detect and compare the power supply voltage of the vehicle power supply. When it is determined that the power supply voltage of the vehicle power supply is overvoltage, the load can be cut off in time to protect the vehicle controller (VCU) from being damaged by overvoltage and to protect the downstream load of the vehicle power supply from being damaged due to the overvoltage of the vehicle power supply. This can effectively prevent the vehicle controller (VCU) from being damaged due to the excessively high power supply voltage of the vehicle power supply.

[0077] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0078] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. An overvoltage protection device for a power supply for a vehicle, characterized by comprising: The application relates to a vehicle power supply protection device. The device comprises a comparison unit, a delay unit and an overvoltage protection unit, which are sequentially arranged between the vehicle power supply and a load, and the overvoltage protection unit is arranged in a load power supply circuit between the vehicle power supply and the load. The comparison unit is configured to sample the power supply voltage of the vehicle power supply, compare the sampled power supply voltage of the vehicle power supply with a reference voltage, output a first level signal when the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and output a second level signal when the power supply voltage of the vehicle power supply is less than the reference voltage. The delay unit is configured to filter the duration of the first level signal when the comparison unit outputs the first level signal, allow the first level signal to output when the duration of the first level signal is greater than or equal to a set delay time, and obtain a delay output signal; and shut off the output of the second level signal when the comparison unit outputs the second level signal. The overvoltage protection unit is configured to disconnect itself when the delay unit outputs the delay output signal, disconnect the load power supply circuit of the vehicle power supply, and realize overvoltage protection of the vehicle power supply; and keep the overvoltage protection unit connected when the comparison unit has no output signal, so that the load power supply circuit is formed between the vehicle power supply and the load of the vehicle power supply. The overvoltage protection unit comprises a voltage follower module, a control module and a switch module. When the delay unit outputs the delay output signal, the overvoltage protection unit is disconnected to disconnect the load power supply circuit of the vehicle power supply, and realize overvoltage protection of the vehicle power supply; and when the comparison unit has no output signal, the overvoltage protection unit is kept connected to form the load power supply circuit between the vehicle power supply and the load of the vehicle power supply. The voltage follower module is configured to make the delay output signal output by the delay unit jump and rise to obtain a driving signal when the delay unit outputs the delay output signal. The control module is configured to make the control module conductive to output a control signal based on the driving signal output by the voltage follower module. The switch module is configured to make the switch module shut off to disconnect the load power supply circuit of the vehicle power supply and realize overvoltage protection of the vehicle power supply based on the control signal output by the control module; and when the comparison unit has no output signal, the control module cannot output the control signal, so that the switch module is kept connected to form the load power supply circuit between the vehicle power supply and the load of the vehicle power supply. ​ 2. The overvoltage protection device for a power supply for a vehicle according to claim 1, characterized by The comparison unit comprises a sampling module, a reference voltage setting module and a comparison module, wherein The comparison unit samples the power supply voltage of the vehicle power supply and compares the sampled power supply voltage of the vehicle power supply with the reference voltage, so as to output a first level signal in the case that the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and output a second level signal in the case that the power supply voltage of the vehicle power supply is less than the reference voltage, comprising: The sampling module is configured to sample the bus voltage of the vehicle power supply to obtain the power supply voltage of the vehicle power supply; The reference voltage setting module is configured to set the reference voltage by using the bus voltage of the vehicle power supply to obtain the reference voltage; The comparison module is configured to compare the sampled power supply voltage of the vehicle power supply with the reference voltage, so as to output a first level signal in the case that the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and output a second level signal in the case that the power supply voltage of the vehicle power supply is less than the reference voltage.

3. The overvoltage protection device for a power supply for a vehicle according to claim 2, characterized by The sampling module comprises a first voltage dividing module, a second voltage dividing module and a third voltage dividing module; the reference voltage setting module comprises a first current limiting module and a first voltage stabilizing module; and the comparison module comprises a comparator module; The bus voltage of the vehicle power supply is connected to the ground through the first voltage dividing module, the second voltage dividing module and the third voltage dividing module, and the common end of the second voltage dividing module and the third voltage dividing module is connected to the non-inverting input end of the comparator module; The bus voltage of the vehicle power supply is connected to the cathode of the first voltage stabilizing module through the first current limiting module, and the anode of the first voltage stabilizing module is connected to the ground; and the common end of the first current limiting module and the first voltage stabilizing module is connected to the inverting input end of the comparator module; The output end of the comparison module is connected to the delay unit to output the first level signal or the second level signal to the delay unit.

4. The overvoltage protection device for a power supply for a vehicle according to any one of claims 1 to 3, characterized in that, The delay unit comprises a delay time setting module and an output module, wherein In the case that the comparison unit outputs the first level signal, the delay unit filters the duration of the first level signal, so as to allow the first level signal to be output in the case that the duration of the first level signal is greater than or equal to the set delay time, and obtain a delay output signal; and in the case that the comparison unit outputs the second level signal, the output of the second level signal is turned off, comprising: The delay time setting module is configured to set the delay time based on the first level signal or the second level signal output by the comparison unit, and filter the first level signal or the second level signal according to the set delay time, so as to filter out the signal with a duration less than the delay time in the first level signal or the second level signal. The output module is configured to be turned on to allow the first level signal filtered by the delay time setting module to be output to obtain a delay output signal in the case that the signal filtered by the delay time setting module is the first level signal; and the output module is turned off to shut off the second level signal filtered by the delay time setting module in the case that the signal filtered by the delay time setting module is the second level signal.

5. The overvoltage protection device for a power supply for a vehicle according to claim 4, characterized by The delay time setting module comprises a charging resistor module and a charging capacitor module; the output module comprises a second voltage stabilizing module; wherein, The output end of the comparison unit is connected to the cathode of the second voltage stabilizing module through the charging resistor module and grounded through the charging capacitor module; the anode of the second voltage stabilizing module is connected to the output end of the delay unit and the overvoltage protection unit; In the case that the signal filtered by the delay time setting module is the first level signal, the second voltage stabilizing module is turned on to allow the first level signal filtered by the delay time setting module to be output to obtain a delay output signal when the charging voltage of the charging capacitor module is greater than the reverse voltage of the second voltage stabilizing module; In the case that the signal filtered by the delay time setting module is the second level signal, the charging voltage of the charging capacitor module is less than the reverse voltage of the second voltage stabilizing module, and the second voltage stabilizing module is turned off to shut off the second level signal filtered by the delay time setting module.

6. The overvoltage protection device for a power supply for a vehicle according to claim 4, characterized by The delay unit further comprises an isolation module; wherein, The isolation module is arranged on the output side of the output module and is configured to isolate and protect the delay output signal output by the output module before output.

7. The overvoltage protection device for a power supply for a vehicle according to claim 1, characterized by The overvoltage protection unit further comprises an overvoltage indication module; the overvoltage indication module is arranged between the output end of the voltage follower module and the ground and is configured to send an indication signal to remind the user that the vehicle power supply has an overvoltage fault when the voltage follower module outputs the driving signal.

8. The overvoltage protection device for a power supply for a vehicle according to claim 1 or 7, characterized in that, The voltage follower module comprises a voltage follower; the control module comprises an input resistor module, a triode module and an output resistor module; the switch module comprises a fourth voltage dividing module, a fifth voltage dividing module and a MOS tube module; wherein, The delay output signal output by the output end of the delay unit is input to the non-inverting input end of the voltage follower; the output end of the voltage follower is connected to the base of the triode module through the input resistor module; the collector of the triode module is connected to the gate of the MOS tube module through the output resistor module; and the emitter of the triode module is grounded; The fourth voltage dividing module and the fifth voltage dividing module are connected in series between the vehicle power supply and the ground; the common end of the fourth voltage dividing module and the fifth voltage dividing module is connected to the gate of the MOS tube module; the source of the MOS tube module is grounded, and the drain of the MOS tube module is connected to a load. In the case that the delay unit outputs the delay output signal, the voltage follower makes the delay output signal outputted by the delay unit jump up to obtain a driving signal; the driving signal makes the triode module conduct, and in the case that the triode module conducts, the gate of the MOS tube module is pulled low to make the MOS tube module turn off; In the case that the delay unit does not output the delay output signal, the voltage follower cannot output the driving signal, and the triode module turns off without the driving of the driving signal, and in the case that the triode module turns off, the gate of the MOS tube module is powered based on the voltage divided by the fourth voltage dividing module and the fifth voltage dividing module to conduct, so as to form a load power supply loop between the vehicle power supply and the load.

9. A vehicle characterized by comprising: The overvoltage protection device of the vehicle power supply comprises: The overvoltage protection device of the vehicle power supply according to any one of claims 1 to 8.

10. A method of overpressure protection of a vehicle as claimed in claim 9, characterized in that The overvoltage protection device of the vehicle power supply comprises: By means of the comparison unit, the power supply voltage of the vehicle power supply is sampled, and the sampled power supply voltage of the vehicle power supply is compared with a reference voltage, so as to output a first level signal in the case that the power supply voltage of the vehicle power supply is greater than or equal to the reference voltage, and output a second level signal in the case that the power supply voltage of the vehicle power supply is less than the reference voltage; By means of the delay unit, in the case that the comparison unit outputs the first level signal, the duration of the first level signal is filtered to allow the first level signal to output in the case that the duration of the first level signal is greater than or equal to a set delay time, so as to obtain a delay output signal; and in the case that the comparison unit outputs the second level signal, the output of the second level signal is turned off; By means of the overvoltage protection unit, in the case that the delay unit outputs the delay output signal, the overvoltage protection unit is disconnected to disconnect the load power supply loop of the vehicle power supply, so as to realize overvoltage protection of the vehicle power supply; and in the case that the comparison unit has no output signal, the overvoltage protection unit is not disconnected, so as to form a load power supply loop between the vehicle power supply and the load of the vehicle power supply.

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