Electric automobile low-voltage power supply system and electric automobile

Abstract

The invention provides an electric vehicle low-voltage power supply system and an electric vehicle. The electric vehicle low-voltage power supply system comprises a direct-current voltage conversion module, a battery management module, an energy storage module and a load. The first positive electrode of the DC voltage conversion module is electrically connected with the first end of the battery management module, and the second positive electrode of the DC voltage conversion module is electrically connected with one end of the load and the positive electrode of the energy storage module. The negative electrode of the direct-current voltage conversion module is electrically connected with the grounding end of the battery management module, the negative electrode of the energy storage module and the other end of the load. The positive electrode of the energy storage module is electrically connected with the second end of the battery management module, and the negative electrode of the energy storage module is electrically connected with the grounding end of the battery management module; the direct-current voltage conversion module receives a control instruction of the battery management module, responds to the control instruction, supplies power to the battery management module and a load after the whole vehicle is powered off, and charges the energy storage module when the energy storage module lacks power; and the energy storage module provides an auxiliary source for the direct-current voltage conversion module, so that power is supplied to equipment of the whole vehicle after the whole vehicle is powered off.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a low-voltage power supply system for electric vehicles and an electric vehicle. Background Art

[0002] The whole vehicle power-off of electric vehicles means disconnecting the high-voltage power supply so that the vehicle's power battery no longer supplies power to high-voltage components such as the drive motor. This usually happens when the vehicle is turned off, parked for a long time, or undergoing maintenance. However, even if the high-voltage power supply is cut off, the vehicle still needs to maintain a certain low-voltage power supply to ensure that certain key functions (such as vehicle safety systems, central control modules, etc.) can operate normally.

[0003] In the prior art, methods for solving the low-voltage power consumption problem of electric vehicles include: solving the problem of long-term power supply of the car refrigerator by changing the cigarette lighter interface wiring harness; solving the problem of charging the lead-acid battery by closing the main relay when the vehicle is parked and idle; solving the problem of being unable to start the vehicle by remotely turning on the intelligent power replenishment function and closing the main relay.

[0004] However, these solutions may easily lead to the risk of damaging the entire vehicle circuit. Summary of the invention

[0005] The purpose of the present application is to provide a low-voltage power supply system for an electric vehicle and an electric vehicle in view of the deficiencies in the above-mentioned prior art, so as to solve the problem of being able to continuously provide low-voltage power supply to the entire vehicle when the entire vehicle is powered off.

[0006] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0007] In a first aspect, an embodiment of the present application provides a low-voltage power supply system for an electric vehicle, the system comprising: a DC voltage conversion module, a battery management module, an energy storage module, and a load;

[0008] The first positive electrode of the DC voltage conversion module is electrically connected to the first end of the battery management module, the second positive electrode of the DC voltage conversion module is electrically connected to one end of the load and the positive electrode of the energy storage module, and the negative electrode of the DC voltage conversion module is electrically connected to the ground end of the battery management module, the negative electrode of the energy storage module and the other end of the load;

[0009] The positive electrode of the energy storage module is electrically connected to the second end of the battery management module, and the negative electrode of the energy storage module is electrically connected to the ground terminal of the battery management module;

[0010] The DC voltage conversion module is used to receive a control instruction of the battery management module electrically connected to the DC voltage conversion module, and in response to the control instruction, supply power to the battery management module electrically connected to the DC voltage conversion module and the load after the vehicle is powered off, and charge the energy storage module electrically connected to the DC voltage conversion module when the energy storage module is in a power-deficient state;

[0011] The energy storage module is used to supply power to the battery management module when the DC voltage conversion module is in a non-working state, and to provide an auxiliary source to the DC voltage conversion module when the DC voltage conversion module is in a low voltage state.

[0012] Optionally, the DC voltage conversion module includes: a DC voltage converter, a power battery, a first diode and an equivalent resistor;

[0013] The first positive electrode of the DC voltage converter is electrically connected to the first end of the battery management module, and the second positive electrode of the DC voltage converter is electrically connected to one end of the load and the positive electrode of the energy storage module respectively;

[0014] The positive electrode of the power battery is electrically connected to the first positive electrode of the DC voltage converter and the second positive electrode of the DC voltage converter respectively, and the negative electrode of the power battery is electrically connected to the negative electrode of the DC voltage converter;

[0015] The anode of the first diode is electrically connected to the second anode of the DC voltage converter, the cathode of the first diode is electrically connected to one end of the equivalent resistor, and the other end of the equivalent resistor is electrically connected to the cathode of the DC voltage converter.

[0016] Optionally, the DC voltage conversion module further includes: a shunt, a first fuse;

[0017] One end of the shunt is electrically connected to the negative electrode of the power battery, and the other end of the shunt is electrically connected to the negative electrode of the DC voltage converter;

[0018] One end of the first fuse is electrically connected to the first positive electrode of the DC voltage converter, and the other end of the first fuse is electrically connected to the first end of the battery management module.

[0019] Optionally, the battery management module includes: a second diode, a third diode and a first resistor;

[0020] The anode of the second diode is electrically connected to the first anode of the DC voltage conversion module, and the cathode of the second diode is electrically connected to the cathode of the third diode and one end of the first resistor respectively;

[0021] The anode of the third diode is electrically connected to the anode of the energy storage module, and the other end of the first resistor is grounded.

[0022] Optionally, it further comprises: a second fuse;

[0023] One end of the second fuse is electrically connected to the second end of the battery management module, and the other end of the second fuse is electrically connected to the positive electrode of the energy storage module.

[0024] Optionally, it further includes: a third fuse;

[0025] One end of the third fuse is electrically connected to the positive electrode of the energy storage module, and the other end of the third fuse is electrically connected to the second positive electrode of the DC voltage conversion module.

[0026] Optionally, it also includes: a vehicle controller;

[0027] The vehicle controller is electrically connected to the battery management module;

[0028] The vehicle controller is used to send control instructions to the battery management module.

[0029] Optionally, the DC voltage conversion module and the battery management module are electrically connected via a hard wire and an internal CAN line respectively.

[0030] Optionally, the battery management module sends a standby instruction to the DC voltage conversion module based on the upper high voltage instruction sent by the vehicle controller;

[0031] The battery management module sends a power-on instruction to the DC voltage conversion module based on the low-voltage instruction sent by the vehicle controller;

[0032] The battery management module sends a low voltage maintenance instruction to the DC voltage conversion module based on the low voltage maintenance instruction sent by the vehicle controller.

[0033] In a second aspect, an embodiment of the present application further provides an electric vehicle, comprising the electric vehicle low-voltage power supply system described in the first aspect.

[0034] The beneficial effects of this application are:

[0035] The present application provides a low-voltage power supply system for electric vehicles and electric vehicles. By electrically connecting the first positive pole of the DC voltage conversion module to the first end of the battery management module and the positive pole of the energy storage module to the second end of the battery management module, it is possible to realize power supply to the battery management module through the DC voltage conversion module and the energy storage module. When the DC voltage conversion module is in a standby state, the energy storage module can supply power to the battery management module. When the DC voltage conversion module is in a working state after the whole vehicle is powered off, the DC voltage conversion module can supply power to the battery management module, so that power can be supplied to the battery management module after the whole vehicle is powered off, so that the battery management module can continue to monitor battery data. The second positive pole of the DC voltage conversion module is electrically connected to one end of the load and the positive pole of the energy storage module respectively, so that after the whole vehicle is powered off, the DC voltage conversion module can continuously supply power to the load and the energy storage module, without the need to close the main relay to supply power to the energy storage module, and the energy storage module will not be in a feeding state, which can extend the life of the energy storage module and solve the problem of long-term power supply to the load. The entire solution integrates the DC voltage conversion module in the battery pack, and by starting the DC voltage conversion module, it can power the entire vehicle equipment. It can solve the problem in the prior art that the load power supply problem is solved by modifying the cigarette lighter interface harness, which causes damage to the entire vehicle circuit, the problem that the battery management module will be in a dormant state and cannot continue to monitor battery data after the vehicle is powered off, and the problem of power supply to the energy storage module. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A schematic diagram of the structure of a low-voltage power supply system for an electric vehicle provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the structure of a DC voltage conversion module provided in an embodiment of the present application;

[0039] Figure 3 A schematic diagram of the structure of a battery management module provided in an embodiment of the present application;

[0040] Figure 4 A schematic diagram of the structure of another low-voltage power supply system for an electric vehicle provided in an embodiment of the present application;

[0041] Figure 5 A schematic diagram of a startup process of a DC voltage converter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0043] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0044] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0045] Figure 1 A schematic diagram of a low-voltage power supply system for an electric vehicle provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the low-voltage power supply system of the electric vehicle may include: a DC voltage conversion module 10, a battery management module 11, an energy storage module 12 and a load 13.

[0046] like Figure 1As shown, the first positive pole of the DC voltage conversion module 10 is electrically connected to the first end of the battery management module 11, the second positive pole of the DC voltage conversion module 10 is electrically connected to one end of the load 13 and the positive pole of the energy storage module 12, respectively, and the negative pole of the DC voltage conversion module 10 can be electrically connected to the ground end of the battery management module 11, the negative pole of the energy storage module 12 and the other end of the load 13, respectively, wherein the load can refer to at least one low-voltage power load, such as a vehicle refrigerator, a large vehicle screen, TBOX or ADAS load. The positive pole of the energy storage module 12 is electrically connected to the second end of the battery management module 11, and the negative pole of the energy storage module 12 is electrically connected to the ground end of the battery management module 11. The energy storage module can be, for example, a lead-acid battery or other batteries.

[0047] Optionally, the DC voltage conversion module 10 can receive control instructions from the battery management module 11 electrically connected to the DC voltage conversion module 10, and respond to the control instructions to supply power to the battery management module 11 electrically connected to the DC voltage conversion module 10 and the load 13 after the vehicle is powered off, and charge the energy storage module 12 electrically connected to the DC voltage conversion module 10 when the energy storage module 12 is in a power-deficient state, so that the energy storage module 12 can always be in a floating charge state, and will not be in a feeding state, thereby ensuring the life of the energy storage module 12. The voltage that the energy storage module 12 can provide can be 12V or 24V.

[0048] Among them, the first positive pole of the DC voltage conversion module 10 can be a voltage output terminal, and the second positive pole of the DC voltage conversion module 10 can be another voltage output terminal. When the DC voltage conversion module 10 is in a working state, the DC voltage conversion module 10 can supply power to the battery management module 11 electrically connected to the first positive pole through the first positive pole, and at the same time, supply power to the load 13 and the energy storage module 12 electrically connected to the second positive pole through the second positive pole. The voltage output by the first positive pole and the second positive pole can be a 12V voltage.

[0049] Optionally, the battery management module 11 may send a control instruction to the DC voltage conversion module 10. After receiving the control instruction, the DC voltage conversion module 10 may perform the operation indicated by the control instruction. For example, before the vehicle is put under high voltage, the vehicle controller may send an instruction to turn on the DC voltage conversion module 10 to the battery management module 11. After receiving the instruction to turn on the DC voltage conversion module 10, the battery management module 11 controls the DC voltage conversion module 10 to turn on.

[0050] Optionally, since the energy storage module 12 is also electrically connected to the battery management module 11, the energy storage module 12 can supply power to the battery management module 11 when the DC voltage conversion module 10 is in a non-working state. Since the energy storage module 12 is electrically connected to the second positive electrode of the DC voltage conversion module 10, an auxiliary source is provided to the DC voltage conversion module 10 when the DC voltage conversion module 10 is in a low voltage state, specifically, the auxiliary source can be provided to the DC voltage conversion module 10 through the second positive electrode of the DC voltage conversion module 10. The DC voltage conversion module 10 is in a low voltage state at the beginning of startup. At this time, a startup auxiliary source can be provided to the DC voltage conversion module 10 through the energy storage module 12, so that the DC voltage conversion module 10 can be started and enter a working state.

[0051] Optionally, the second positive pole of the DC voltage conversion module 10 is both a voltage output terminal and a voltage input terminal. Specifically, when the DC voltage conversion module 10 is in a startup state, the second positive pole is a voltage input terminal, and the energy storage module 12 provides an auxiliary source to the DC voltage conversion module 10 through the second positive pole; when the DC voltage conversion module 10 is started, that is, in a working state, the second positive pole is a voltage output terminal, and power can be supplied to the energy storage module 12 and the load respectively through the second positive pole.

[0052] In this embodiment, by electrically connecting the first positive pole of the DC voltage conversion module to the first end of the battery management module, and the positive pole of the energy storage module to the second end of the battery management module, it is possible to realize that the DC voltage conversion module and the energy storage module supply power to the battery management module. When the DC voltage conversion module is in a standby state, the energy storage module can supply power to the battery management module. When the DC voltage conversion module is in a working state after the whole vehicle is powered off, the DC voltage conversion module can supply power to the battery management module, so that the battery management module can be powered after the whole vehicle is powered off, so that the battery management module can continue to monitor battery data. The second positive pole of the DC voltage conversion module is electrically connected to one end of the load and the positive pole of the energy storage module respectively, so that after the whole vehicle is powered off, the DC voltage conversion module can continuously supply power to the load and the energy storage module, without the need to close the main relay to supply power to the energy storage module, and the energy storage module will not be in a feeding state, which can extend the life of the energy storage module and solve the problem of long-term power supply to the load. The entire solution integrates the DC voltage conversion module in the battery pack, and by starting the DC voltage conversion module, it can power the entire vehicle equipment. It can solve the problem in the prior art that the load power supply problem is solved by modifying the cigarette lighter interface harness, which causes damage to the entire vehicle circuit, the problem that the battery management module will be in a dormant state and cannot continue to monitor battery data after the vehicle is powered off, and the problem of power supply to the energy storage module.

[0053] Figure 2A schematic diagram of the structure of a DC voltage conversion module provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the DC voltage conversion module 10 may include: a DC voltage converter 101 , a power battery 102 , a first diode 103 and an equivalent resistor 106 .

[0054] like Figure 2 As shown, the first positive electrode of the DC-to-DC converter 101 is electrically connected to the first end of the battery management module 11, and the second positive electrode of the DC-to-DC converter 101 is electrically connected to one end of the load 13 and the positive electrode of the energy storage module 12. Specifically, the second positive electrode of the DC-to-DC converter 101 can be electrically connected to one end of the load 13 through a wire, and the second positive electrode of the DC-to-DC converter 101 can also be electrically connected to the positive electrode of the energy storage module 12 through a wire.

[0055] Optionally, the positive electrode of the power battery 102 is electrically connected to the first positive electrode of the DC voltage converter 101 and the second positive electrode of the DC voltage converter 101, respectively, and the negative electrode of the power battery 102 is electrically connected to the negative electrode of the DC voltage converter 101. Then the power battery 102 is the high voltage input side of the DC voltage converter 101, and the DC voltage converter 101 can convert the high voltage of the power battery 102 into a low voltage. The voltage range of the power battery 102 can be, for example, 350V to 800V. The power battery 102 can be a ternary or iron-lithium system.

[0056] The anode of the first diode 103 is electrically connected to the second anode of the DC voltage converter 101 , the cathode of the first diode 103 is electrically connected to one end of the equivalent resistor 106 , and the other end of the equivalent resistor 106 is electrically connected to the cathode of the DC voltage converter 101 .

[0057] Optionally, when the DC voltage converter 101 is in a low voltage state, the positive electrode voltage of the first diode 103 is greater than the negative electrode voltage of the first diode 103. At this time, the energy storage module 12 can supply power to the DC voltage converter 101 via the first diode 103, thereby providing a startup auxiliary source to the DC voltage converter 101, so that the DC voltage converter 101 can be started. When the DC voltage converter 101 is in a working state, the DC voltage converter 101 can output a low voltage. At this time, the positive electrode voltage of the first diode 103 is less than the negative electrode voltage of the first diode 103. The low voltage output by the DC voltage converter 101 does not flow back to the DC voltage converter 101 via the first diode 103, but flows out to supply power to the load 13 and the energy storage module 12.

[0058] In this embodiment, the DC voltage converter is integrated in the battery pack. When the DC voltage converter is in a low voltage state, that is, when the DC voltage converter is in the startup phase, the energy storage module can provide an auxiliary source to the DC voltage converter through the first diode and the equivalent resistor, so that the DC voltage converter can start. When the DC voltage converter is successfully started, that is, when the DC voltage converter is in a working state, the DC voltage converter can convert the high voltage side voltage of the power battery into a low voltage output, and provide a low voltage to the load and the energy storage module electrically connected to the second positive pole of the DC voltage converter, and at the same time provide a low voltage to the battery management module electrically connected to the first positive pole of the DC voltage converter.

[0059] Continue as Figure 2 As shown, the DC voltage conversion module 10 may further include: a shunt 104 and a first fuse 105. One end of the shunt 104 may be electrically connected to the negative electrode of the power battery 102, and the other end of the shunt 104 may be electrically connected to the negative electrode of the DC voltage converter 101. The shunt 104 may collect the high voltage side current.

[0060] Optionally, one end of the first fuse 105 may be electrically connected to the first positive electrode of the DC voltage converter 101 , and the other end of the first fuse 105 may be electrically connected to the first end of the battery management module 11 .

[0061] In this embodiment, when the DC voltage converter is in working state, the low voltage output of the DC voltage converter can flow to the battery management module via the first fuse. The first fuse can protect the circuit.

[0062] Figure 3 A schematic diagram of the structure of a battery management module provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the battery management module 11 may include: a second diode 110 , a third diode 111 and a first resistor 112 .

[0063] like Figure 3 As shown, the anode of the second diode 110 is electrically connected to the first anode of the DC voltage conversion module 10. Specifically, the anode of the second diode 110 can be electrically connected to the other end of the first fuse 105 in the DC voltage conversion module 10. The cathode of the second diode 110 is electrically connected to the cathode of the third diode 111 and one end of the first resistor 112. The anode of the third diode 111 can be electrically connected to the anode of the energy storage module 12, and the other end of the first resistor 112 is grounded.

[0064] Optionally, when the DC voltage converter 101 is in a non-operating state, the output voltage of the energy storage module 12 can be connected to the ground via the third diode 111 and the first resistor 112, thereby providing a low voltage to the battery management module 11. When the DC voltage converter 101 is in an operating state, the low voltage output of the DC voltage converter 101 is connected to the ground via the first fuse 105, the second diode 110 and the first resistor 112, thereby providing a low voltage to the battery management module 11. This allows the battery management module 11 to work normally and continuously monitor battery data.

[0065] Figure 4 A schematic diagram of the structure of another low-voltage power supply system for an electric vehicle provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the system may further include: a second fuse 14 .

[0066] like Figure 4 As shown, one end of the second fuse 14 is electrically connected to the second end of the battery management module 11, specifically, one end of the second fuse 14 is electrically connected to the positive electrode of the third diode 111 in the battery management module 11, and the other end of the second fuse 14 can be electrically connected to the positive electrode of the energy storage module 12. Then, when the DC voltage converter 101 is in a non-operating state, the output voltage of the energy storage module 12 can be connected to the ground via the second fuse 14, the third diode 111 and the first resistor 112, thereby providing a low voltage to the battery management module 11.

[0067] like Figure 4 As shown, the system may further include: a third fuse 15. One end of the third fuse 15 may be electrically connected to the positive electrode of the energy storage module 12, and the other end of the third fuse 15 may be electrically connected to the second positive electrode of the DC voltage conversion module 10. Specifically, the other end of the third fuse 15 may be electrically connected to the positive electrode of the first diode 103 in the DC voltage conversion module 10 and the second positive electrode of the DC voltage converter 101, respectively.

[0068] The low voltage output of the DC voltage converter 101 can be connected to the ground via the second positive electrode of the DC voltage converter 101, the third fuse 15 and the energy storage module 12, thereby supplying power to the energy storage module 12. When the DC voltage converter 101 is at a low voltage, the voltage of the energy storage module 12 can flow into the DC voltage converter 101 via the third fuse 15, the first diode 103 and the equivalent resistor 106, thereby providing a startup auxiliary source to the DC voltage converter 101, so that the DC voltage converter 101 can start normally and work.

[0069] Continue as Figure 4 As shown, the system may also include: a vehicle controller 16.

[0070] Among them, the vehicle control unit 16 (VCU) can be electrically connected to the battery management module 11, and the vehicle control unit 16 can send control instructions to the battery management module 11. Specifically, the vehicle control unit 16 can be electrically connected to the battery management module 11 through the power CAN, and the vehicle control unit 16 can send control instructions to the battery management module 11 through the power CAN, and the battery management module 11 can also return the execution result after executing the operation indicated by the control instruction to the vehicle control unit 16 through the power CAN.

[0071] Optionally, the DC voltage conversion module 10 and the battery management module 11 are electrically connected via hard wire and internal CAN, respectively. Specifically, the DC voltage converter 101 in the DC voltage conversion module 10 can be electrically connected to the battery management module 11 via hard wire and internal CAN, respectively.

[0072] The battery management module 11 can wake up the DC voltage converter 101 through a hard line, and when the DC voltage converter 101 is in a working state, it can communicate with the battery management module 11 through the internal CAN.

[0073] Optionally, the battery management module 11 may send a standby instruction to the DC voltage conversion module 10 based on the high voltage instruction sent by the vehicle controller 16. Specifically, during the power-on period of the vehicle, the battery management module 11 may receive the high voltage instruction sent by the vehicle controller 16, and then the battery management module 11 may send a standby instruction to the DC voltage conversion module 10, such as requesting DCDC to start the instruction = "standby", so that the DC voltage converter 101 in the DC voltage conversion module 10 is in a standby state, and at this time, the energy storage module 12 may supply power to the battery management module 11.

[0074] Optionally, the battery management module 11 sends a power-on instruction to the DC voltage conversion module 10 based on the high-voltage down instruction sent by the vehicle controller 16. Specifically, during the period when the vehicle is powered off, the vehicle controller 16 can send a high-voltage down instruction to the battery management module 11. After the battery management module 11 receives the high-voltage down instruction, it sends a power-on instruction to the DC voltage conversion module 10, such as requesting a DCDC start instruction = "power on", so that the DC voltage converter 101 in the DC voltage conversion module 10 is powered on.

[0075] Optionally, the battery management module 11 can send a low voltage maintenance instruction to the DC voltage conversion module 10 based on the low voltage maintenance instruction sent by the vehicle controller 16. When OTA is upgraded, the battery management module 11 can receive the low voltage maintenance instruction sent by the vehicle controller 16, and the battery management module 11 can control the DC voltage converter 101 in the DC voltage conversion module 10 to enter the OTA low voltage output mode, at which time the DC voltage converter 101 in the battery pack is powered.

[0076] Optionally, when the DC voltage converter 101 is working normally (not OTA upgrade), the battery management module 11 can communicate and interact with the DC voltage converter 101 through the internal CAN, and the vehicle CAN can stop sending messages according to the network management specification so that other controllers of the vehicle can sleep normally. That is, when the DC voltage converter 101 is successfully started, the vehicle stops sending messages.

[0077] Optionally, when the DC voltage converter 101 is working normally (non-OTA upgrade), if the battery management module 11 detects that the DC voltage converter 101 has a serious fault or the power battery 102 has a serious fault that causes the DC voltage converter 101 to be unable to continue working, the battery management module 11 can actively wake up the vehicle network and inform the vehicle controller 16 that the DC voltage converter 101 has a fault.

[0078] Optionally, the shutdown condition of the DC voltage converter 101 includes at least one of the following conditions: (1) the battery management module receives a shutdown command sent by the vehicle controller; (2) the DC voltage converter has a level 3 fault (such as the CAN fault signal or the hard-line signal is a high level); (3) the battery management module has a serious fault (such as the fault level is greater than or equal to the requested power-off level); (4) the SOC of the power battery is ≤10%; (5) the minimum single cell voltage of the power battery is ≤ the undervoltage level 1 threshold; (6) the internal CAN BUS is OFF; (7) the PT CAN related software is upgraded; (8) the DC voltage converter message is lost; (9) the maintenance switch state is disconnected; (10) the battery temperature is too high.

[0079] Figure 5 A schematic diagram of a DC voltage converter startup process provided in an embodiment of the present application is shown in FIG. Figure 5As shown, the DCDC startup scenarios can include the following two: one is that DCDC needs to be started when the vehicle is under high voltage, and the other is that DCDC output needs to be started during OTA upgrade. After the DC voltage converter 101 (DCDC) receives the startup instruction sent by the battery management module 11, the auxiliary source is first connected, that is, the energy storage module 12 is connected. The energy storage module 12 provides the startup auxiliary source to the DC voltage converter, so that the DC voltage converter starts, first starts the high voltage side, and then starts the low voltage side to output a low voltage of 12V.

[0080] An embodiment of the present application also provides an electric vehicle, including the electric vehicle low-voltage power supply system in the aforementioned specific embodiment.

[0081] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication electrical connection shown or discussed can be through some communication interfaces, indirect coupling or communication electrical connection of devices or modules, which can be electrical, mechanical or other forms.

[0082] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), disk or optical disk and other media that can store program code.

[0083] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A low-voltage power supply system for an electric vehicle, characterized in that: The system comprises: a DC voltage conversion module, a battery management module, an energy storage module and a load; The first positive electrode of the DC voltage conversion module is electrically connected to the first end of the battery management module, the second positive electrode of the DC voltage conversion module is electrically connected to one end of the load and the positive electrode of the energy storage module, and the negative electrode of the DC voltage conversion module is electrically connected to the ground end of the battery management module, the negative electrode of the energy storage module and the other end of the load; The positive electrode of the energy storage module is electrically connected to the second end of the battery management module, and the negative electrode of the energy storage module is electrically connected to the ground terminal of the battery management module; The DC voltage conversion module is used to receive a control instruction of the battery management module electrically connected to the DC voltage conversion module, and in response to the control instruction, supply power to the battery management module electrically connected to the DC voltage conversion module and the load after the vehicle is powered off, and charge the energy storage module electrically connected to the DC voltage conversion module when the energy storage module is in a power-deficient state; The energy storage module is used to supply power to the battery management module when the DC voltage conversion module is in a non-working state, and to provide an auxiliary source to the DC voltage conversion module when the DC voltage conversion module is in a low voltage state.

2. The low-voltage power supply system for electric vehicles according to claim 1, characterized in that: The DC voltage conversion module includes: a DC voltage converter, a power battery, a first diode and an equivalent resistor; The first positive electrode of the DC voltage converter is electrically connected to the first end of the battery management module, and the second positive electrode of the DC voltage converter is electrically connected to one end of the load and the positive electrode of the energy storage module respectively; The positive electrode of the power battery is electrically connected to the first positive electrode of the DC voltage converter and the second positive electrode of the DC voltage converter respectively, and the negative electrode of the power battery is electrically connected to the negative electrode of the DC voltage converter; The anode of the first diode is electrically connected to the second anode of the DC voltage converter, the cathode of the first diode is electrically connected to one end of the equivalent resistor, and the other end of the equivalent resistor is electrically connected to the cathode of the DC voltage converter.

3. The low-voltage power supply system for electric vehicles according to claim 2, characterized in that: The DC voltage conversion module further includes: a shunt and a first fuse; One end of the shunt is electrically connected to the negative electrode of the power battery, and the other end of the shunt is electrically connected to the negative electrode of the DC voltage converter; One end of the first fuse is electrically connected to the first positive electrode of the DC voltage converter, and the other end of the first fuse is electrically connected to the first end of the battery management module.

4. The low-voltage power supply system for electric vehicles according to claim 1, characterized in that: The battery management module includes: a second diode, a third diode and a first resistor; The anode of the second diode is electrically connected to the first anode of the DC voltage conversion module, and the cathode of the second diode is electrically connected to the cathode of the third diode and one end of the first resistor respectively; The anode of the third diode is electrically connected to the anode of the energy storage module, and the other end of the first resistor is grounded.

5. The low-voltage power supply system for electric vehicles according to claim 1, characterized in that: Also includes: Second fuse; One end of the second fuse is electrically connected to the second end of the battery management module, and the other end of the second fuse is electrically connected to the positive electrode of the energy storage module.

6. The low-voltage power supply system for electric vehicles according to claim 1, characterized in that: Also includes: The third fuse; One end of the third fuse is electrically connected to the positive electrode of the energy storage module, and the other end of the third fuse is electrically connected to the second positive electrode of the DC voltage conversion module.

7. The electric vehicle low-voltage power supply system according to claim 1, characterized in that: Also includes: Vehicle controller; The vehicle controller is electrically connected to the battery management module; The vehicle controller is used to send control instructions to the battery management module.

8. The low-voltage power supply system for electric vehicles according to claim 1, characterized in that: The DC voltage conversion module and the battery management module are electrically connected via a hard line and an internal CAN line respectively.

9. The low-voltage power supply system for electric vehicles according to claim 7, characterized in that: The battery management module sends a standby instruction to the DC voltage conversion module based on the upper high voltage instruction sent by the vehicle controller; The battery management module sends a power-on instruction to the DC voltage conversion module based on the low-voltage instruction sent by the vehicle controller; The battery management module sends a low voltage maintenance instruction to the DC voltage conversion module based on the low voltage maintenance instruction sent by the vehicle controller.

10. An electric vehicle, characterized in that: The invention comprises a low-voltage power supply system for an electric vehicle as described in any one of claims 1 to 9.

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