Vehicle low-voltage power supply and vehicle

Abstract

The utility model provides a vehicle low-voltage power supply and a vehicle. The power supply comprises a DC power supply, at least one isolation switch and a short circuit detection circuit. For any isolating switch, the isolating switch is connected in series between the output end of the direct-current power supply and the first load corresponding to the isolating switch, and the control end of the isolating switch is connected with the short-circuit detection circuit; the short circuit detection circuit is configured to detect whether the first load corresponding to the isolating switch is short-circuited or not, and send a disconnection instruction to the isolating switch when detecting that the first load corresponding to the isolating switch is short-circuited; the disconnection instruction is used for indicating disconnection of the disconnecting switch. The isolation switches are arranged in the paths of the first loads which are prone to short circuit, the short circuit fault is removed in time when short circuit occurs, the voltage of the direct-current power supply is prevented from being lowered, it is ensured that all the power protection loads can work normally, and the safety and reliability of the vehicle are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of automobiles, in particular to a vehicle low-voltage power supply and a vehicle. Background Art

[0002] With the development of the automobile industry, cars are increasingly involved in our daily life and work. The number of vehicles in my country has reached 345 million. With the popularity of cars, vehicle accidents are also increasing. Therefore, the safety and reliability of cars are of vital importance.

[0003] In the prior art, when a car collides, if part of the load is short-circuited, the main power supply may be pulled down, resulting in power failure of the door lock controller and the airbag controller, and then the door cannot be unlocked and the occupants in the car cannot escape, which poses certain safety hazards and reduces the safety and reliability of the vehicle. Utility Model Content

[0004] The embodiment of the utility model provides a vehicle low-voltage power supply and a vehicle, so as to solve the problem in the prior art that part of the load is short-circuited during a collision, the main power supply is pulled low, and the vehicle door cannot be unlocked.

[0005] In a first aspect, an embodiment of the utility model provides a low-voltage power supply for a vehicle, comprising: a DC power supply, at least one isolating switch and a short-circuit detection circuit; the DC power supply is used to supply power to each first load and each second load; each isolating switch corresponds to a first load;

[0006] For any isolating switch, the isolating switch is connected in series between the output end of the DC power supply and the first load corresponding to the isolating switch, and the control end of the isolating switch is connected to the short-circuit detection circuit; the short-circuit detection circuit is configured to detect whether the first load corresponding to the isolating switch is short-circuited, and when the first load corresponding to the isolating switch is detected to be short-circuited, a disconnection instruction is sent to the isolating switch; the disconnection instruction is used to instruct the isolating switch to disconnect;

[0007] The output terminal of the DC power supply is also connected to each second load.

[0008] Optionally, the short circuit detection circuit includes: at least one overcurrent detection unit, at least one overvoltage detection unit and a main control chip; each isolation switch corresponds to an overcurrent detection unit and an overvoltage detection unit;

[0009] For any overcurrent detection unit, the overcurrent detection unit is configured to detect whether the current flowing through the isolation switch corresponding to the overcurrent detection unit is overcurrent, and output different voltage values ​​to the main control chip through the output end of the overcurrent detection unit to indicate whether there is overcurrent;

[0010] For any overvoltage detection unit, the overvoltage detection unit is configured to detect whether the voltage difference across the isolating switch corresponding to the overvoltage detection unit is overvoltage, and output different voltage values ​​to the main control chip through the output end of the overvoltage detection unit to indicate whether it is overvoltage;

[0011] The main control chip is also used to receive the collision signal, and send a disconnection instruction to each isolation switch based on the voltage value of the output end of each overcurrent detection unit, the voltage value of the output end of each overvoltage detection unit and the collision signal.

[0012] Optionally, the overcurrent detection unit includes: a current sensor, a voltage dividing subunit, a following subunit and a first comparing subunit;

[0013] The current sensor is arranged in the passage where the isolating switch corresponding to the overcurrent detection unit is located, and is used to detect the current flowing through the isolating switch;

[0014] The input end of the voltage divider subunit is connected to the voltage output end of the current sensor, and the output end of the voltage divider subunit is connected to the input end of the follower subunit;

[0015] The output end of the follower subunit is connected to the first input end of the first comparison subunit, the second input end of the first comparison subunit is used to input the first reference voltage, and the output end of the first comparison subunit forms the output end of the overcurrent detection unit.

[0016] Optionally, the first comparison subunit includes: a first comparator, a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a third capacitor;

[0017] A first comparator, wherein the positive input terminal is respectively connected to the first end of the first resistor, the first end of the second resistor and the first end of the second capacitor, the negative input terminal is connected to the first end of the first capacitor, the negative input terminal also forms the first input terminal of the first comparison subunit, and the output terminal is respectively connected to the first end of the third capacitor, the first end of the third resistor and the second end of the second resistor, and the output terminal also forms the output terminal of the first comparison subunit;

[0018] The second end of the first resistor forms the second input end of the first comparison subunit; the second end of the third resistor is connected to the power supply;

[0019] The second end of the first capacitor, the second end of the second capacitor and the second end of the third capacitor are all grounded.

[0020] Optionally, the overvoltage detection unit includes: a differential amplification subunit and a second comparison subunit;

[0021] The first input end of the differential amplifier subunit is connected to the first end of the isolation switch corresponding to the overvoltage detection unit, the second input end of the differential amplifier subunit is connected to the second end of the isolation switch corresponding to the overvoltage detection unit, and the output end of the differential amplifier subunit is connected to the first input end of the second comparison subunit;

[0022] The second input terminal of the second comparing subunit is used to input a second reference voltage, and the output terminal of the second comparing subunit forms the output terminal of the overvoltage detection unit.

[0023] Optionally, the vehicle low-voltage power supply further includes: an energy storage module;

[0024] The energy storage module is connected to the output end of the DC power supply.

[0025] Optionally, the vehicle low-voltage power supply further includes: at least one fuse; each fuse corresponds to a second load;

[0026] For any one fuse, the fuse is connected in series between the output end of the DC power supply and the second load corresponding to the fuse.

[0027] Optionally, the first load is a radiator fan.

[0028] Optionally, the second load is: a door lock controller or an airbag controller.

[0029] In a second aspect, an embodiment of the utility model provides a vehicle, comprising a vehicle low-voltage power supply provided by any one of the embodiments of the first aspect above.

[0030] The embodiment of the utility model provides a vehicle low-voltage power supply and a vehicle. The vehicle low-voltage power supply includes: a DC power supply, at least one isolating switch and a short-circuit detection circuit; the DC power supply is used to supply power to each first load and each second load; each isolating switch corresponds to a first load; for any isolating switch, the isolating switch is connected in series between the output end of the DC power supply and the first load corresponding to the isolating switch, and the control end of the isolating switch is connected to the short-circuit detection circuit; the short-circuit detection circuit is configured to detect whether the first load corresponding to the isolating switch is short-circuited, and when the first load corresponding to the isolating switch is detected to be short-circuited, a disconnection instruction is sent to the isolating switch; the disconnection instruction is used to instruct the isolating switch to disconnect; the output end of the DC power supply is also connected to each second load. In the embodiment of the utility model, an isolating switch is set in the passage where each first load that is prone to short-circuit during a collision is located, and the short-circuit fault is removed in time when a collision short-circuit occurs, so as to avoid pulling down the output voltage of the DC power supply, thereby ensuring the stability of the power supply to each second load and ensuring the power supply to each second load that needs to be powered. For example, the second load may be a door controller. When a collision occurs, the power supply of the door controller is not pulled down and the door can be opened normally, which effectively improves the safety and reliability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 It is a structural schematic diagram of a low-voltage power supply for a vehicle provided by an embodiment of the utility model;

[0033] Figure 2 It is a circuit structure schematic diagram of a short circuit detection circuit provided by an embodiment of the utility model;

[0034] Figure 3 is a circuit schematic diagram of a first comparison subunit provided by an embodiment of the utility model;

[0035] Figure 4 It is a structural schematic diagram of another vehicle low-voltage power supply provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0036] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0037] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0038] For new energy vehicles, such as EV (Electric Vehicle) or hybrid vehicles, the radiator fan, airbag controller, body controller (control door locks), etc. are all powered by the same power supply. When a vehicle collides, some loads represented by the radiator are very likely to short-circuit, which will lower the voltage of the entire power supply, thereby affecting the power supply of the airbag controller and the body controller, causing the door locks to fail to open, affecting the escape of people in the car, and seriously affecting the safety and reliability of the vehicle.

[0039] Based on the above problems, the present invention provides a schematic diagram of the structure of a low-voltage power supply for a vehicle. Figure 1 The vehicle low-voltage power supply includes: a DC power supply 1, at least one isolating switch K1 and a short-circuit detection circuit 2; the DC power supply 1 is used to supply power to each first load and each second load; each isolating switch K1 corresponds to a first load;

[0040] For any isolating switch K1, the isolating switch K1 is connected in series between the output end of the DC power supply 1 and the first load corresponding to the isolating switch K1, and the control end of the isolating switch K1 is connected to the short-circuit detection circuit 2; the short-circuit detection circuit 2 is configured to detect whether the first load corresponding to the isolating switch K1 is short-circuited, and when the first load corresponding to the isolating switch K1 is detected to be short-circuited, a disconnection instruction is sent to the isolating switch K1; the disconnection instruction is used to instruct the isolating switch K1 to disconnect;

[0041] The output end of the DC power supply 1 is also connected to each second load.

[0042] refer to Figure 1, the DC power supply 1 supplies power to each first load and each second load. Each first load is some load in the car that is prone to short circuit, such as a radiator fan, etc.; each second load is some load in the car that needs to be powered, such as an airbag controller and a body controller, etc. For each first load that is prone to short circuit during a collision, an isolating switch K1 is provided in the passage of each first load, which is used to cut it off in time when a short circuit occurs; the short circuit detection circuit 2 is configured to detect whether each first load is short-circuited, and control the isolating switch K1 to disconnect when a short circuit is detected, so as to cut off the short-circuited first load. By providing the isolating switch K1 and the short circuit detection circuit 2, the embodiment of the utility model can cut off the short-circuited first load in time when a short circuit occurs in each first load, thereby preventing the output voltage of the DC power supply 1 from being pulled down, ensuring the continuity of power supply to each second load, and effectively improving the safety and stability of the vehicle.

[0043] In a possible implementation, the short circuit detection circuit 2 may include: at least one overcurrent detection unit 21, at least one overvoltage detection unit 22 and a main control chip U1; each isolation switch K1 corresponds to an overcurrent detection unit 21 and an overvoltage detection unit 22;

[0044] For any overcurrent detection unit 21, the overcurrent detection unit 21 is configured to detect whether the current flowing through the isolation switch K1 corresponding to the overcurrent detection unit 21 is overcurrent, and output different voltage values ​​to the main control chip U1 through the output end of the overcurrent detection unit 21 to indicate whether there is overcurrent;

[0045] For any overvoltage detection unit 22, the overvoltage detection unit 22 is configured to detect whether the voltage difference across the isolating switch K1 corresponding to the overvoltage detection unit 22 is overvoltage, and output different voltage values ​​to the main control chip U1 through the output end of the overvoltage detection unit 22 to indicate whether there is overvoltage;

[0046] The main control chip U1 is also used to receive the collision signal Sig1, and send a disconnection instruction to each isolation switch K1 based on the voltage value of the output end of each overcurrent detection unit 21, the voltage value of the output end of each overvoltage detection unit 22 and the collision signal Sig1.

[0047] Figure 2 A circuit structure diagram of a short circuit detection circuit 2 including only one overcurrent detection unit 21 and one overvoltage detection unit 22 is shown;

[0048] When a first load is short-circuited, the current flowing through the corresponding isolating switch K1 will rise rapidly, resulting in overcurrent. Based on this, an overcurrent detection unit 21 is provided corresponding to each isolating switch K1 to detect whether the current flowing through the isolating switch K1 is overcurrent;

[0049] At the same time, when a first load is short-circuited, the voltage at the first load end will be rapidly reduced, and a large voltage difference will be generated on both sides of the isolating switch K1. Based on this, an overvoltage detection unit 22 is also provided for each isolating switch K1 to detect whether the voltage difference on both sides of the isolating switch K1 is overvoltage.

[0050] Furthermore, when a collision occurs, the airbag controller sends a collision signal Sig1, and the main control chip U1 can also receive the collision signal Sig1, combined with the output voltage value of each overcurrent detection unit 21 and the output voltage value of each overvoltage detection unit 22, to comprehensively determine whether each first load is short-circuited, and then control each isolation switch K1.

[0051] Based on the above, the judgment logic of the main control chip U1 can be: for a certain isolation switch K1, if the collision signal Sig1 is detected, and overcurrent and overvoltage are detected at the same time, the isolation switch K1 is controlled to be disconnected;

[0052] For another example, for a certain isolating switch K1, if a collision signal Sig1 is detected and an overcurrent or overvoltage is detected at the same time, that is, only one of the overcurrent and overvoltage is satisfied, the isolating switch K1 is controlled to be disconnected;

[0053] For another example, for a certain isolating switch K1, if any two of the three conditions of detecting a collision signal Sig1, detecting an overcurrent, and detecting an overvoltage are met, the isolating switch K1 is controlled to be disconnected;

[0054] The main control chip U1 can be a single-chip microcomputer. The specific judgment logic of the main control chip U1 includes but is not limited to the above several types, which can be set according to actual application requirements and are conventional technical means in this field. This application only protects the hardware circuit including the main control chip U1, and does not protect the judgment logic, which is not the invention point of this application.

[0055] In one possible implementation, reference Figure 2 , the overcurrent detection unit 21 may include: a current sensor 211, a voltage dividing subunit 212, a following subunit 213 and a first comparing subunit 214;

[0056] The current sensor 211 is arranged in the path where the isolating switch K1 corresponding to the overcurrent detection unit 21 is located, and is used to detect the current flowing through the isolating switch K1;

[0057] The input end of the voltage divider unit 212 is connected to the voltage output end of the current sensor 211, and the output end of the voltage divider unit 212 is connected to the input end of the follower unit 213;

[0058] The output end of the follower subunit 213 is connected to the first input end of the first comparison subunit 214 . The second input end of the first comparison subunit 214 is used to input the first reference voltage VREF1 . The output end of the first comparison subunit 214 forms the output end of the overcurrent detection unit 21 .

[0059] The current sensor 211 is arranged in the path where the isolating switch K1 is located, detects the current flowing through the isolating switch K1, and converts it into a voltage signal output; the voltage dividing subunit 212 is used to divide the voltage signal output by the current sensor 211 to meet the voltage requirements of the device; the following subunit 213 is used for buffering, isolation, reducing output impedance, reducing current consumption, and reducing the impact of the access of the overcurrent detection unit 21 on the power supply path of the DC power supply 1; the first comparison subunit 214 is used for voltage comparison and outputting the overcurrent detection result. When the current flowing through the isolating switch K1 is less than the preset current, the first comparison subunit 214 outputs a first level to indicate that there is no overcurrent; when the current flowing through the isolating switch K1 is not less than the preset current, the first comparison subunit 214 outputs a second level to indicate that there is an overcurrent. The main control chip U1 determines whether there is an overcurrent based on the voltage value output by the first comparison subunit 214.

[0060] The magnitude of the preset current can be set according to actual application requirements, and is not specifically limited here. Specifically, the magnitude of the preset current can be adjusted by adjusting the first reference voltage VREF1.

[0061] In one possible implementation, reference Figure 3 , the first comparison subunit 214 may include: a first comparator U2, a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2 and a third capacitor C3;

[0062] A first comparator U2, wherein a positive input terminal is respectively connected to a first end of the first resistor R1, a first end of the second resistor R2, and a first end of the second capacitor C2, a negative input terminal is connected to a first end of the first capacitor C1, and the negative input terminal also forms a first input terminal of a first comparison subunit 214, and an output terminal is respectively connected to a first end of a third capacitor C3, a first end of the third resistor R3, and a second end of the second resistor R2, and the output terminal also forms an output terminal of the first comparison subunit 214;

[0063] The second end of the first resistor R1 forms the second input end of the first comparison subunit 214; the second end of the third resistor R3 is connected to the power supply VCC1;

[0064] A second end of the first capacitor C1 , a second end of the second capacitor C2 , and a second end of the third capacitor C3 are all grounded.

[0065] refer to Figure 3In the embodiment of the utility model, the first comparison subunit 214 is implemented by a hysteresis comparator to avoid frequent changes in the output voltage of the first comparison subunit 214 when the current flowing through the isolation switch K1 is near a preset current, thereby affecting the detection result.

[0066] Exemplarily, the voltage divider subunit 212 can be implemented by resistor voltage division; the follower subunit 213 can be implemented by a comparator; the specific circuits of the voltage divider subunit 212 and the follower subunit 213 are conventional technical means in the field, and will not be described in detail here.

[0067] In one possible implementation, reference Figure 2 , the overvoltage detection unit 22 may include: a differential amplification subunit 221 and a second comparison subunit 222;

[0068] The first input end of the differential amplifier unit 221 is connected to the first end of the isolation switch K1 corresponding to the overvoltage detection unit 22, the second input end of the differential amplifier unit 221 is connected to the second end of the isolation switch K1 corresponding to the overvoltage detection unit 22, and the output end of the differential amplifier unit 221 is connected to the first input end of the second comparison subunit 222;

[0069] The second input terminal of the second comparison subunit 222 is used to input the second reference voltage VREF2 , and the output terminal of the second comparison subunit 222 forms the output terminal of the overvoltage detection unit 22 .

[0070] The differential amplifier unit 221 is used to obtain the voltage difference across the isolating switch K1 and amplify it; the second comparison subunit 222 is also used for voltage comparison and outputs an overvoltage detection result; when the voltage difference across the isolating switch K1 is less than the preset voltage, the second comparison subunit 222 outputs a third level to indicate that there is no overvoltage; when the voltage difference across the isolating switch K1 is not less than the preset voltage, the second comparison subunit 222 outputs a fourth level to indicate that there is an overvoltage.

[0071] Specifically, the second comparison subunit 222 may also be implemented by using a hysteresis comparator, as can be seen in Figure 3 Detailed description of the circuit structure of the first comparison subunit 214.

[0072] The differential amplifier unit 221 may also be implemented by a comparator. The specific circuit is a conventional technical means in the art and will not be described in detail here.

[0073] In one possible implementation, reference Figure 1 , the vehicle low-voltage power supply may also include: an energy storage module 3;

[0074] The energy storage module 3 is connected to the output end of the DC power supply 1 .

[0075] The embodiment of the utility model is further provided with an energy storage module 3. When the DC power supply 1 fails, the energy storage module 3 can be used to supply power to each first load and each second load, thereby ensuring stable power supply to each load.

[0076] Exemplarily, the energy storage module 3 may be a battery.

[0077] In one possible implementation, reference Figure 4 , the vehicle low-voltage power supply may further include: at least one fuse; each fuse corresponds to a second load;

[0078] For any fuse, the fuse is connected in series between the output end of the DC power supply 1 and the second load corresponding to the fuse.

[0079] The present application may also provide a fuse in the power supply path of each second load to prevent overcurrent of each second load and improve the reliability of the circuit.

[0080] In one possible implementation, reference Figure 4 , the first load may be a radiator fan.

[0081] The radiator fan is very likely to short-circuit during a collision, so it is classified as the first load so that it can be removed in time when a short circuit occurs. The first load can also be other loads in the cabin that are prone to short circuits.

[0082] In one possible implementation, reference Figure 4 The second load may be: a door lock controller or an airbag controller.

[0083] The door lock controller (which may be a body controller) and the airbag controller may be classified as the second load, and their power supply needs to be ensured.

[0084] Corresponding to the above embodiments, an embodiment of the utility model further provides a vehicle, comprising a vehicle low-voltage power supply provided by any of the above embodiments, and having the advantages of any of the above vehicle low-voltage power supplies, which will not be described in detail here.

[0085] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-voltage power supply for a vehicle, characterized in that: include: a DC power supply, at least one isolating switch and a short circuit detection circuit; The DC power supply is used to supply power to each first load and each second load; each isolating switch corresponds to a first load; For any isolating switch, the isolating switch is connected in series between the output end of the DC power supply and the first load corresponding to the isolating switch, and the control end of the isolating switch is connected to the short-circuit detection circuit; the short-circuit detection circuit is configured to detect whether the first load corresponding to the isolating switch is short-circuited, and when the first load corresponding to the isolating switch is detected to be short-circuited, a disconnection instruction is sent to the isolating switch; the disconnection instruction is used to instruct the isolating switch to disconnect; The output end of the DC power supply is also connected to each second load.

2. The vehicle low-voltage power supply according to claim 1, characterized in that: The short circuit detection circuit comprises: at least one overcurrent detection unit, at least one overvoltage detection unit and a main control chip; each isolating switch corresponds to an overcurrent detection unit and an overvoltage detection unit; For any overcurrent detection unit, the overcurrent detection unit is configured to detect whether the current flowing through the isolation switch corresponding to the overcurrent detection unit is overcurrent, and output different voltage values ​​to the main control chip through the output end of the overcurrent detection unit to indicate whether there is overcurrent; For any overvoltage detection unit, the overvoltage detection unit is configured to detect whether the voltage difference across the isolating switch corresponding to the overvoltage detection unit is overvoltage, and output different voltage values ​​to the main control chip through the output end of the overvoltage detection unit to indicate whether there is overvoltage; The main control chip is also used to receive a collision signal, and send the disconnection instruction to each isolation switch based on the voltage value of the output end of each overcurrent detection unit, the voltage value of the output end of each overvoltage detection unit and the collision signal.

3. The vehicle low-voltage power supply according to claim 2, characterized in that: The overcurrent detection unit includes: a current sensor, a voltage dividing subunit, a following subunit and a first comparing subunit; The current sensor is arranged in the passage where the isolating switch corresponding to the overcurrent detection unit is located, and is used to detect the current flowing through the isolating switch; The input end of the voltage dividing subunit is connected to the voltage output end of the current sensor, and the output end of the voltage dividing subunit is connected to the input end of the following subunit; The output end of the follower subunit is connected to the first input end of the first comparison subunit, the second input end of the first comparison subunit is used to input a first reference voltage, and the output end of the first comparison subunit forms the output end of the overcurrent detection unit.

4. The vehicle low-voltage power supply as claimed in claim 3, characterized in that: The first comparison subunit includes: a first comparator, a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a third capacitor; The first comparator has a positive input terminal connected to the first end of the first resistor, the first end of the second resistor and the first end of the second capacitor, a negative input terminal connected to the first end of the first capacitor, the negative input terminal also forming the first input terminal of the first comparison subunit, and an output terminal connected to the first end of the third capacitor, the first end of the third resistor and the second end of the second resistor, and the output terminal also forming the output terminal of the first comparison subunit; The second end of the first resistor forms the second input end of the first comparison subunit; the second end of the third resistor is connected to the power supply; The second end of the first capacitor, the second end of the second capacitor and the second end of the third capacitor are all grounded.

5. The vehicle low-voltage power supply according to claim 2, characterized in that: The overvoltage detection unit includes: a differential amplification subunit and a second comparison subunit; The first input end of the differential amplifier subunit is connected to the first end of the isolation switch corresponding to the overvoltage detection unit, the second input end of the differential amplifier subunit is connected to the second end of the isolation switch corresponding to the overvoltage detection unit, and the output end of the differential amplifier subunit is connected to the first input end of the second comparison subunit; The second input terminal of the second comparing subunit is used to input a second reference voltage, and the output terminal of the second comparing subunit forms the output terminal of the overvoltage detecting unit.

6. The vehicle low-voltage power supply according to any one of claims 1 to 5, characterized in that: The vehicle low-voltage power supply also includes: an energy storage module; The energy storage module is connected to the output end of the DC power supply.

7. The vehicle low-voltage power supply according to any one of claims 1 to 5, characterized in that: The vehicle low-voltage power supply also includes: at least one fuse; each fuse corresponds to a second load; For any one fuse, the fuse is connected in series between the output end of the DC power supply and the second load corresponding to the fuse.

8. The vehicle low-voltage power supply according to any one of claims 1 to 5, characterized in that: The first load is a radiator fan.

9. The vehicle low-voltage power supply according to any one of claims 1 to 5, characterized in that: The second load is: a door lock controller or an airbag controller.

10. A vehicle, characterized in that: Comprising a vehicle low-voltage power supply as claimed in any one of claims 1 to 9.

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