Power supply system for vehicle and control method therefor

Abstract

The invention discloses a power supply system of a vehicle and a control method thereof, the system comprises a power battery pack, the power battery pack comprises a power battery, a first DCDC converter and a switching device, the output end of the power battery is connected with the input end of the first DCDC converter, and the first end of the switching device is connected with the output end of the power battery; the high-voltage input end of the second DCDC converter is connected with the second end of the switching device, and the low-voltage input end of the second DCDC converter is connected with the output end of the first DCDC converter; the vehicle control unit is used for responding to a starting signal of a vehicle, controlling the first DCDC converter to convert a first voltage output by the power battery into a second voltage and outputting the second voltage to the second DCDC converter; and controlling the switching device to be in a conducting state, so that the power battery outputs the first voltage to the second DCDC converter. According to the invention, the technical problem of how to cancel the storage battery configuration of the vehicle is solved.

Description

Technical Field

[0001] This invention belongs to the field of power supply technology, and in particular relates to a power supply system for a vehicle and its control method. Background Technology

[0002] During vehicle startup, a battery is required as a starting power source. With the rapid development of the automotive industry, there is an urgent need to design vehicles that do not require a battery, as equipping vehicles with batteries presents numerous problems. For example, vehicles left unused for extended periods may fail to start due to a depleted battery. Furthermore, batteries are consumables with high unit costs and high maintenance and replacement costs, making the elimination of battery configurations a growing trend. Therefore, how to eliminate the need for a vehicle battery is a pressing technical problem that needs to be solved. Summary of the Invention

[0003] This invention provides a vehicle power supply system and its control method, solving the technical problem of how to eliminate the need for a vehicle battery.

[0004] In a first aspect, embodiments of the present invention provide a power supply system for a vehicle, comprising: a power battery pack, the power battery pack including a power battery, a first DC-DC converter, and a switching device, wherein the output terminal of the power battery is connected to the input terminal of the first DC-DC converter, and a first terminal of the switching device is connected to the output terminal of the power battery; a second DC-DC converter, the high-voltage input terminal of the second DC-DC converter being connected to a second terminal of the switching device, and the low-voltage input terminal of the second DC-DC converter being connected to the output terminal of the first DC-DC converter, the output terminal of the second DC-DC converter being used to supply power to a low-voltage load of the vehicle; and a vehicle controller electrically connected to the switching device and the first DC-DC converter, the vehicle controller being configured to: in response to a start signal of the vehicle, control the first DC-DC converter to convert a first voltage output by the power battery into a second voltage and output the second voltage to the second DC-DC converter, the second voltage being lower than the first voltage; and control the switching device to be in a conducting state, so that the power battery outputs the first voltage to the second DC-DC converter.

[0005] In conjunction with the first aspect of the present invention, in some embodiments, the high-voltage input terminal of the second DC-DC converter includes a positive input terminal and a negative input terminal; the switching device includes: a first relay, the normally open contact of the first relay being connected to the positive terminal of the power battery, the common contact of the first relay being connected to the positive input terminal of the second DC-DC converter, and the control terminal of the first relay being connected to the vehicle controller; and a second relay, the normally open contact of the second relay being connected to the negative terminal of the power battery, the common contact of the second relay being connected to the negative input terminal of the second DC-DC converter, and the control terminal of the second relay being connected to the vehicle controller.

[0006] In conjunction with the first aspect of the present invention, in some embodiments, the second DC-DC converter includes: a first DC-DC conversion circuit, wherein a first input terminal of the first DC-DC conversion circuit is connected to a second terminal of the switching device, and a second input terminal of the first DC-DC conversion circuit is connected to an output terminal of the first DC-DC converter, the output terminal of the first DC-DC conversion circuit being used to supply power to a first type of low-voltage load of the vehicle, wherein the first type of low-voltage load is a low-voltage load with a rated power greater than a first preset power threshold; and a second DC-DC conversion circuit, wherein a first input terminal of the second DC-DC conversion circuit is connected to the output terminal of the first DC-DC conversion circuit, and a second input terminal of the second DC-DC conversion circuit is connected to the output terminal of the first DC-DC converter, the output terminal of the second DC-DC conversion circuit being used to supply power to a second type of low-voltage load and a third type of low-voltage load of the vehicle, wherein the third type of low-voltage load includes a variety of low-voltage loads related to the driving safety of the vehicle, and the second type of low-voltage load includes the third type of low-voltage load and low-voltage loads other than the first type of low-voltage load.

[0007] In conjunction with the first aspect of the present invention, in some embodiments, the invention further includes: a first power distribution mechanism electrically connected to the vehicle controller; the first power distribution mechanism includes a first switch, a second switch, and a third switch; the output terminal of the second DC-DC converter is connected to a second type of low-voltage load through the first switch; the output terminal of the second DC-DC converter is connected to a third type of low-voltage load through the second switch; and the output terminal of the first DC-DC converter is connected to the third type of low-voltage load through the third switch. The vehicle controller is further configured to: control the first switch and the second switch to close, and control the third switch to open, when the vehicle is started and the second DC-DC converter is fault-free; and control the first switch and the second switch to open, and control the third switch to close, when the vehicle is started and the second DC-DC converter is faulty.

[0008] In conjunction with the first aspect of the present invention, in some embodiments, the vehicle controller is further configured to: after controlling the first switch and the second switch to close, and controlling the third switch to open, monitor the total load power of each load powered by the output of the second DC-DC conversion circuit; if the total load power is greater than a second preset power threshold, control the third switch to close.

[0009] In conjunction with the first aspect of the present invention, in some embodiments, the first type of low-voltage load includes the vehicle's fan, water pump, and actuator; the second type of low-voltage load includes the vehicle's audio-visual entertainment system, body system, and lighting system; and the third type of low-voltage load includes the vehicle's power system and chassis system.

[0010] In conjunction with the first aspect of the present invention, in some embodiments, the invention further includes: a second power distribution mechanism, the second power distribution mechanism including a fourth switch and a fifth switch, wherein the power supply terminal of the vehicle controller is connected to the output terminal of the first DC-DC converter through the fourth switch, and the power supply terminal of the vehicle controller is connected to the output terminal of the second DC-DC converter through the fifth switch; wherein, when the vehicle is started, the fourth switch is closed and the fifth switch is open; after the vehicle is started, the fourth switch is open and the fifth switch is closed.

[0011] In conjunction with the first aspect of the present invention, in some embodiments, it further includes: a housing, wherein the power battery, the first DC-DC converter and the switching device are all disposed inside the housing; and the second DC-DC converter is disposed outside the housing.

[0012] In conjunction with the first aspect of the present invention, in some embodiments, the first DC-DC converter is a DC-DC converter with an output voltage of 12V, the first DC-DC conversion circuit is a DC-DC converter with an output voltage of 48V, and the second DC-DC conversion circuit is a DC-DC converter with an output voltage of 12V.

[0013] In a second aspect, embodiments of the present invention provide a control method for a vehicle power supply system, applied to a vehicle power supply system as described in any one of the first aspects, the method comprising: in response to a vehicle start signal, controlling a first DC-DC converter to convert a first voltage output by a power battery into a second voltage, and outputting the second voltage to a second DC-DC converter, wherein the second voltage is lower than the first voltage; controlling a switching device to be in a conducting state, so that the power battery outputs the first voltage to the second DC-DC converter.

[0014] The one or more technical solutions provided in the embodiments of the present invention achieve at least the following technical effects or advantages:

[0015] This invention provides a vehicle power supply system, comprising: a power battery pack, including a power battery, a first DC-DC converter, and a switching device, wherein the output terminal of the power battery is connected to the input terminal of the first DC-DC converter, and the first terminal of the switching device is connected to the output terminal of the power battery; a second DC-DC converter, wherein the high-voltage input terminal of the second DC-DC converter is connected to the second terminal of the switching device, and the low-voltage input terminal of the second DC-DC converter is connected to the output terminal of the first DC-DC converter, and the output terminal of the second DC-DC converter is used to supply power to the low-voltage load of the vehicle; and a vehicle controller electrically connected to the switching device and the first DC-DC converter, the vehicle controller being configured to: in response to a vehicle start signal, control the first DC-DC converter to convert a first voltage output from the power battery into a second voltage and output the second voltage to the second DC-DC converter, the second voltage being lower than the first voltage; and control the switching device to be in a conducting state, so that the power battery outputs the first voltage to the second DC-DC converter. Since the first DC-DC converter is directly connected to the power battery, the first DC-DC converter is always powered, thus the first DC-DC converter can replace the battery as a starting power source. Specifically, in response to the vehicle's start signal, the first DC-DC converter supplies low-voltage electricity to the second DC-DC converter, while the power battery supplies high-voltage electricity to the second DC-DC converter. This enables the second DC-DC converter to supply power to the vehicle's low-voltage load to start the vehicle. Therefore, the vehicle's battery configuration is eliminated.

[0016] Furthermore, eliminating the vehicle's battery configuration avoids battery depletion, thus reducing the likelihood of the vehicle failing to start. At the same time, without a battery, there's no need for future battery replacements and maintenance, reducing vehicle operating costs and the frequency of maintenance. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a first schematic diagram of the power supply system of a vehicle in an embodiment of the present invention;

[0019] Figure 2 This is a second schematic diagram of the vehicle's power supply system in an embodiment of the present invention;

[0020] Figure 3This is a third schematic diagram of the vehicle's power supply system in an embodiment of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0023] Figure 1 This is a first schematic diagram of a vehicle's power supply system according to an embodiment of the present invention. (Reference) Figure 1 As shown, an embodiment of the present invention provides a vehicle power supply system including: a power battery pack, comprising a power battery 10, a first DC-DC converter 20, and a switching device 30, wherein the output terminal of the power battery 10 is connected to the input terminal of the first DC-DC converter 20, and the first terminal of the switching device 30 is connected to the output terminal of the power battery 10; a second DC-DC converter 40, wherein the high-voltage input terminal of the second DC-DC converter 40 is connected to the second terminal of the switching device 30, and the low-voltage input terminal of the second DC-DC converter 40 is connected to the output terminal of the first DC-DC converter 20, and the output terminal of the second DC-DC converter 40 is used to supply power to the low-voltage load 50 of the vehicle; and a vehicle controller electrically connected to the switching device 30 and the first DC-DC converter 20, the vehicle controller being used to: in response to a vehicle start signal, control the first DC-DC converter 20 to convert the first voltage output by the power battery 10 into a second voltage and output the second voltage to the second DC-DC converter 40, wherein the second voltage is lower than the first voltage; and control the switching device 30 to be in a conducting state so that the power battery 10 outputs the first voltage to the second DC-DC converter 40.

[0024] It should be noted that a DC-DC converter is an electronic device that converts direct current (DC) voltage or current into another different voltage or current. It is widely used in power management, energy conversion, and power supply for electronic devices. Low-voltage loads in a vehicle refer to electrical equipment in the vehicle's electrical system that operates at relatively low voltages, such as 12V, 24V, or 48V.

[0025] In some embodiments, the high-voltage input terminal of the second DC-DC converter 40 includes a positive input terminal and a negative input terminal; the switching device 30 may include: a first relay, the normally open contact of which is connected to the positive terminal of the power battery 10, the common contact of which is connected to the positive input terminal of the second DC-DC converter 40, and the control terminal of which is connected to the vehicle controller; and a second relay, the normally open contact of which is connected to the negative terminal of the power battery 10, the common contact of which is connected to the negative input terminal of the second DC-DC converter 40, and the control terminal of which is connected to the vehicle controller.

[0026] It should be noted that, through the control of the vehicle controller, the normally open contact of the first relay can be connected to the common contact of the first relay, and the normally open contact of the second relay can be connected to the common contact of the second relay, that is, the switching device 30 is in the conducting state.

[0027] refer to Figure 2 As shown, Figure 2 This is a second schematic diagram of the vehicle's power supply system in an embodiment of the present invention. The second DC-DC converter 40 may include: a first DC-DC conversion circuit 410, the first input terminal of the first DC-DC conversion circuit 410 being connected to the second terminal of the switching device 30, the second input terminal of the first DC-DC conversion circuit 410 being connected to the output terminal of the first DC-DC converter 20, and the output terminal of the first DC-DC conversion circuit 410 being used to supply power to a first type of low-voltage load 510 of the vehicle, wherein the first type of low-voltage load 510 is a low-voltage load with a rated power greater than a first preset power threshold; the second DC-DC converter... In circuit 420, the first input terminal of the second DC-DC converter circuit 420 is connected to the output terminal of the first DC-DC converter circuit 410, and the second input terminal of the second DC-DC converter circuit 420 is connected to the output terminal of the first DC-DC converter 20. The output terminal of the second DC-DC converter circuit 420 is used to supply power to the second type low-voltage load 520 and the third type low-voltage load 530 of the vehicle. The third type low-voltage load 530 includes various low-voltage loads related to the driving safety of the vehicle. The second type low-voltage load 520 includes low-voltage loads other than the third type low-voltage load 530 and the first type low-voltage load 510.

[0028] It should be noted that the second DC-DC converter 40 may consist of only one DC-DC conversion circuit, which supplies power to the first type low-voltage load 510, the second type low-voltage load 520, and the third type low-voltage load 530 together. This simplifies the circuit, but it also has some shortcomings. Specifically, the output voltage of a single DC-DC conversion circuit is constant, such as 12V. This can normally meet the needs of the second type low-voltage load 520 and the third type low-voltage load 530. However, when supplying power to the first type low-voltage load 510, the output voltage is too low, resulting in excessive current and thus excessive energy consumption. Therefore, the embodiments of the present invention define the second DC-DC converter 40 as including a first DC-DC conversion circuit 410 and a second DC-DC conversion circuit 420. The output voltage of the first DC-DC conversion circuit 410 is greater than the output voltage of the second DC-DC conversion circuit 420. Then, the second DC-DC conversion circuit 420 can supply power to the second type of low-voltage load 520 and the third type of low-voltage load 530, while the first DC-DC conversion circuit 410 supplies power to the first type of low-voltage load 510, thereby reducing the current supplied to the first type of low-voltage load 510 and thus achieving the beneficial effect of reducing power consumption.

[0029] It should be noted that the low-voltage load 50 of the vehicle may include a first type of low-voltage load 510, a second type of low-voltage load 520 and a third type of low-voltage load 530. The first type of low-voltage load 510 includes the vehicle's fan, water pump and actuator; the second type of low-voltage load 520 includes the vehicle's audio-visual entertainment system, body system and lighting system; and the third type of low-voltage load 530 includes the vehicle's power system and chassis system.

[0030] refer to Figure 3 As shown, Figure 3 This is a third schematic diagram of the vehicle power supply system in an embodiment of the present invention. The vehicle power supply system may further include: a first power distribution mechanism 60, electrically connected to the vehicle controller; the first power distribution mechanism 60 includes a first switch, a second switch, and a third switch; the output terminal of the second DC-DC converter 420 is connected to a second type of low-voltage load 520 through the first switch; the output terminal of the second DC-DC converter 420 is connected to a third type of low-voltage load 530 through the second switch; and the output terminal of the first DC-DC converter 20 is connected to the third type of low-voltage load 530 through the third switch. The vehicle controller is further configured to: control the first and second switches to close and control the third switch to open when the vehicle is started and the second DC-DC converter 420 is fault-free; and control the first and second switches to open and control the third switch to close when the vehicle is started and the second DC-DC converter 420 is faulty.

[0031] It should be noted that when the first switch is closed, the second switch is closed, and the third switch is open, power is supplied to the third type low-voltage load 530 and the second type low-voltage load 520 through the second DC-DC converter circuit 420. When the first switch is open, the second switch is open, and the third switch is closed, power is supplied to the third type low-voltage load 530 through the first DC-DC converter 20. It is important to emphasize that, by setting up the first power distribution mechanism 60, this embodiment of the invention ensures that when the second DC-DC converter circuit 420 malfunctions, power can still be supplied to the third type low-voltage load 530 through the first DC-DC converter 20, thus guaranteeing the vehicle's basic safe driving needs. In other words, the power supply to the third type low-voltage load 530 has double protection, thereby achieving the beneficial effect of improving vehicle driving safety.

[0032] In some embodiments, the vehicle controller is also configured to: monitor the total load power of each load supplied by the second DC-DC converter circuit 420 after controlling the first and second switches to close and the third switch to open; and control the third switch to close if the total load power is greater than a second preset power threshold.

[0033] It should be noted that excessive total load power may cause the second DC-DC converter circuit 420 to overload, thereby damaging it. Therefore, this embodiment of the invention specifies that if the total load power exceeds a second preset power threshold, the third switch is closed. That is, when there is an overload risk in the second DC-DC converter circuit 420, the first DC-DC converter 20 is introduced to jointly supply power to the third type of low-voltage load 530, thereby reducing the overload risk of the second DC-DC converter circuit 420 and preventing damage to it.

[0034] It should be noted that the vehicle controller can be continuously powered by the first DC-DC converter 20, or by both the first DC-DC converter 20 and the second DC-DC converter 40, or by either the first DC-DC converter 20 or the second DC-DC converter 40 at different times. The following explains the scenario where the vehicle controller is powered by either the first DC-DC converter 20 or the second DC-DC converter 40 at different times:

[0035] In some embodiments, the vehicle's power supply system may further include: a second power distribution mechanism, which includes a fourth switch and a fifth switch. The power supply terminal of the vehicle controller is connected to the output terminal of the first DC-DC converter 20 through the fourth switch, and the power supply terminal of the vehicle controller is connected to the output terminal of the second DC-DC converter 40 through the fifth switch. When the vehicle is started, the fourth switch is closed and the fifth switch is open; after the vehicle is started, the fourth switch is open and the fifth switch is closed.

[0036] It should be noted that when the vehicle is started, the fourth switch is closed and the fifth switch is open, at which time the first DC-DC converter 20 supplies power to the vehicle controller; after the vehicle is started, the fourth switch is open and the fifth switch is closed, at which time the second DC-DC converter 40 supplies power to the vehicle controller.

[0037] In some embodiments, the vehicle's power supply system may further include: a housing 70, a power battery 10, a first DC-DC converter 20 and a switching device 30 all disposed inside the housing 70; and a second DC-DC converter 40 disposed outside the housing 70.

[0038] In some implementations, the first DC-DC converter 20 is a DC-DC converter with an output voltage of 12V, the first DC-DC conversion circuit 410 is a DC-DC converter with an output voltage of 48V, and the second DC-DC conversion circuit 420 is a DC-DC converter with an output voltage of 12V.

[0039] It should be noted that when the first DC-DC conversion circuit 410 is a DC-DC converter with an output voltage of 48V, the second DC-DC conversion circuit 420 can specifically be a 48V to 12V DC-DC converter. More specifically, the first DC-DC converter 20 is a DC-DC converter with a rated power of 1kW and an output voltage of 12V, the first DC-DC conversion circuit 410 is a DC-DC converter with a rated power of 2kW and an output voltage of 48V, and the second DC-DC conversion circuit 420 is a DC-DC converter with a rated power of 1kW and an output voltage of 12V. It should also be noted that a supercapacitor with a rated power of 350W can be installed inside the power battery pack. Furthermore, the first type of low-voltage load can refer to the vehicle's high-power low-voltage load, the second type of low-voltage load can refer to the vehicle's conventional low-voltage load, and the third type of low-voltage load can refer to the vehicle's safe low-voltage load.

[0040] It should be noted that with the continuous improvement of vehicle intelligence and electrification, the current power and safety level of a single DC-DC converter are no longer sufficient for the overall vehicle requirements. It is necessary to improve the power and safety levels of the DC-DC converter. Currently, most new energy vehicles use a single DC-DC converter to achieve energy conversion from the high-voltage platform to the low-voltage platform, which presents the following problems: increasing the power of a single DC-DC converter leads to a sharp increase in cost and quality risks, and also hinders modular design of the DC-DC converter; if the DC-DC converter fails, the vehicle cannot guarantee safe operation, and the safety of passengers cannot be guaranteed; as the vehicle load increases, the energy consumption of the low-voltage system also increases, leading to increased vehicle energy consumption. Therefore, this invention proposes a dual DC-DC converter solution to solve the problems of a single DC-DC converter. Specifically, the dual DC-DC converter includes a first DC-DC converter 20 and a second DC-DC converter 40. Furthermore, during vehicle startup, a battery is required as a starting power source. With the rapid development of the automotive industry, there is an urgent need to design a vehicle that does not require a battery, as equipping a vehicle with a battery presents many problems. For example, vehicles left unused for extended periods may fail to start due to a depleted battery. Furthermore, batteries are consumables with high unit costs and high maintenance and replacement costs, making the elimination of battery configurations a growing trend. Therefore, how to eliminate the battery configuration in vehicles is a pressing technical problem. To address these issues, embodiments of the present invention provide a vehicle power supply system.

[0041] This invention provides a vehicle power supply system, comprising: a power battery pack, including a power battery 10, a first DC-DC converter 20, and a switching device 30, wherein the output terminal of the power battery 10 is connected to the input terminal of the first DC-DC converter 20, and the first terminal of the switching device 30 is connected to the output terminal of the power battery 10; a second DC-DC converter 40, the high-voltage input terminal of the second DC-DC converter 40 being connected to the second terminal of the switching device 30, and the low-voltage input terminal of the second DC-DC converter 40 being connected to the output terminal of the first DC-DC converter 20, the output terminal of the second DC-DC converter 40 being used to supply power to a low-voltage load 50 of the vehicle; and a vehicle controller, electrically connected to the switching device 30 and the first DC-DC converter 20, the vehicle controller being configured to: in response to a vehicle start signal, control the first DC-DC converter 20 to convert a first voltage output from the power battery 10 into a second voltage and output the second voltage to the second DC-DC converter 40, the second voltage being lower than the first voltage; and control the switching device 30 to be in a conducting state so that the power battery 10 outputs the first voltage to the second DC-DC converter 40. Since the first DC-DC converter 20 is directly connected to the power battery 10, it is always powered and can replace the battery as a starting power source. Specifically, in response to the vehicle's start signal, the first DC-DC converter 20 provides low-voltage power to the second DC-DC converter 40, while the power battery 10 provides high-voltage power to the second DC-DC converter 40. This allows the second DC-DC converter 40 to supply power to the vehicle's low-voltage load 50 to start the vehicle. Therefore, the vehicle's battery configuration is eliminated. Furthermore, eliminating the battery configuration avoids battery depletion, reducing the likelihood of the vehicle failing to start. Simultaneously, without a battery, there is no need for subsequent battery replacement and maintenance, reducing vehicle operating costs and the frequency of maintenance.

[0042] Based on the same inventive concept, embodiments of the present invention provide a control method for a vehicle power supply system, applied to a vehicle power supply system. The method includes: in response to a vehicle start signal, controlling a first DC-DC converter 20 to convert a first voltage output by a power battery 10 into a second voltage, and outputting the second voltage to a second DC-DC converter 40, wherein the second voltage is lower than the first voltage; controlling a switching device 30 to be in a conducting state, so that the power battery 10 outputs the first voltage to the second DC-DC converter 40.

[0043] In some embodiments, the control method for the vehicle's power supply system may further include: after the vehicle is started and there is no fault in the second DC-DC conversion circuit, controlling the first switch and the second switch to close, and controlling the third switch to open; after the vehicle is started and there is a fault in the second DC-DC conversion circuit, controlling the first switch and the second switch to open, and controlling the third switch to close.

[0044] In some embodiments, the control method for the vehicle's power supply system may further include: after controlling the first switch and the second switch to close, and controlling the third switch to open, monitoring the total load power of each load supplied through the second DC-DC conversion circuit; if the total load power is greater than a second preset power threshold, controlling the third switch to close.

[0045] It should be understood that further implementation details of the control method of the vehicle power supply system in the embodiments of the present invention refer to the aforementioned description of the vehicle power supply system, and will not be repeated here for the sake of brevity.

[0046] 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. A power supply system for a vehicle, characterized in that, include: A power battery pack, comprising a power battery, a first DC-DC converter, and a switching device, wherein the output terminal of the power battery is connected to the input terminal of the first DC-DC converter, and the first terminal of the switching device is connected to the output terminal of the power battery. The second DC-DC converter has its high-voltage input terminal connected to the second terminal of the switching device, and its low-voltage input terminal connected to the output terminal of the first DC-DC converter. The output terminal of the second DC-DC converter is used to supply power to the low-voltage load of the vehicle. The vehicle controller is electrically connected to the switching device and the first DC-DC converter. The vehicle controller is configured to: in response to a vehicle start signal, control the first DC-DC converter to convert a first voltage output by the power battery into a second voltage and output the second voltage to the second DC-DC converter, wherein the second voltage is lower than the first voltage; and control the switching device to be in an on state so that the power battery outputs the first voltage to the second DC-DC converter.

2. The vehicle power supply system according to claim 1, characterized in that, The high-voltage input terminal of the second DC-DC converter includes a positive input terminal and a negative input terminal; the switching device includes: The first relay has its normally open contact connected to the positive terminal of the power battery, its common contact connected to the positive input terminal of the second DC-DC converter, and its control terminal connected to the vehicle controller. The second relay has its normally open contact connected to the negative terminal of the power battery, its common contact connected to the negative input terminal of the second DC-DC converter, and its control terminal connected to the vehicle controller.

3. The vehicle power supply system according to claim 1, characterized in that, The second DC-DC converter includes: A first DC-DC converter circuit, wherein the first input terminal of the first DC-DC converter circuit is connected to the second terminal of the switching device, the second input terminal of the first DC-DC converter circuit is connected to the output terminal of the first DC-DC converter, and the output terminal of the first DC-DC converter circuit is used to supply power to a first type of low-voltage load of the vehicle, wherein the first type of low-voltage load is a low-voltage load with a rated power greater than a first preset power threshold. A second DC-DC converter circuit has a first input terminal connected to the output terminal of the first DC-DC converter circuit, and a second input terminal connected to the output terminal of the first DC-DC converter circuit. The output terminal of the second DC-DC converter circuit is used to supply power to the vehicle's second-class low-voltage loads and third-class low-voltage loads. The third-class low-voltage loads include various low-voltage loads related to the vehicle's driving safety. The second-class low-voltage loads include the third-class low-voltage loads and low-voltage loads other than the first-class low-voltage loads.

4. The vehicle power supply system according to claim 3, characterized in that, Also includes: The first power distribution mechanism is electrically connected to the vehicle controller. The first power distribution mechanism includes a first switch, a second switch, and a third switch. The output terminal of the second DC-DC converter is connected to the second type of low-voltage load through the first switch. The output terminal of the second DC-DC converter is connected to the third type of low-voltage load through the second switch. The output terminal of the first DC-DC converter is connected to the third type of low-voltage load through the third switch. The vehicle controller is further configured to: control the first switch and the second switch to close and control the third switch to open when the vehicle is started and the second DC-DC conversion circuit is fault-free; and control the first switch and the second switch to open and control the third switch to close when the vehicle is started and the second DC-DC conversion circuit is faulty.

5. The vehicle power supply system according to claim 4, characterized in that, The vehicle controller is also used for: After controlling the first switch and the second switch to close, and controlling the third switch to open, monitor the total load power of each load powered by the output of the second DC-DC conversion circuit; if the total load power is greater than a second preset power threshold, control the third switch to close.

6. The vehicle power supply system according to claim 3, characterized in that, The first type of low-pressure load includes the vehicle's fan, water pump, and actuators; The second type of low-voltage load includes the vehicle's audio-visual entertainment system, body system, and lighting system; The third type of low-pressure load includes the vehicle's power system and chassis system.

7. The vehicle power supply system according to claim 1, characterized in that, Also includes: The second power distribution mechanism includes a fourth switch and a fifth switch. The power supply terminal of the vehicle controller is connected to the output terminal of the first DC-DC converter through the fourth switch, and the power supply terminal of the vehicle controller is connected to the output terminal of the second DC-DC converter through the fifth switch. When the vehicle is started, the fourth switch is closed and the fifth switch is open; after the vehicle is started, the fourth switch is open and the fifth switch is closed.

8. The vehicle power supply system according to claim 1, characterized in that, Also includes: The housing, the power battery, the first DC-DC converter, and the switching device are all disposed inside the housing; The second DC-DC converter is located outside the housing.

9. The power supply system for the vehicle according to any one of claims 3-6, characterized in that, The first DC-DC converter is a DC-DC converter with an output voltage of 12V, the first DC-DC conversion circuit is a DC-DC converter with an output voltage of 48V, and the second DC-DC conversion circuit is a DC-DC converter with an output voltage of 12V.

10. A control method for a vehicle power supply system, applied to the vehicle power supply system as described in any one of claims 1-9, characterized in that, The method includes: In response to the vehicle's start signal, the first DC-DC converter is controlled to convert the first voltage output by the power battery into a second voltage, and outputs the second voltage to the second DC-DC converter, wherein the second voltage is lower than the first voltage; The switching device is controlled to be in the on state so that the power battery outputs the first voltage to the second DC-DC converter.

Images