Pre-charging control method and device of vehicle battery management system, terminal equipment and storage medium

Abstract

The invention discloses a pre-charging control method and device for a vehicle battery management system, terminal equipment and a storage medium, and the method comprises the steps: obtaining a starting power supply voltage and a first output voltage of a DC converter when a high-voltage power-on instruction is obtained, and carrying out the pre-charging control of the vehicle battery management system when the first output voltage or the starting power supply voltage is determined to be greater than a first preset voltage; therefore, the safety of the vehicle in the high-voltage power-on process is effectively guaranteed, secondly, in the pre-charging process, whether pre-charging of the direct-current bus capacitor is completed or not is judged by monitoring the internal and external voltage difference of the battery and the voltage of the direct-current bus at the same time, and the pre-charging relay is switched on to pre-charge the direct-current bus capacitor. Therefore, the situation that the BMS misjudges that pre-charging is completed due to the fact that the voltage of the direct-current bus is affected when the vehicle system is under-voltage is avoided, the risk of misjudgment of the BMS is effectively reduced, the current acquisition circuit is prevented from being impacted by large surges, the reliability and stability of the battery management system are enhanced, and the safety performance of the electric vehicle is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle technology, and in particular to a pre-charging control method, device, terminal equipment and storage medium for a vehicle battery management system. Background Art

[0002] In the field of electric vehicles, the battery management system (BMS) plays a vital role in ensuring the safety and reliability of the battery pack. When the high-voltage circuit of the electric vehicle is powered on, the BMS needs to control the pre-charge relay to close to charge the DC bus capacitor, so that the DC bus capacitor voltage gradually rises until it reaches the same or close level as the battery voltage, and then the battery is directly connected to the high-voltage bus through the main relay. This process is designed to avoid high-voltage shocks that damage high-voltage components, thereby improving the safety and reliability of the high-voltage system. In this process, the current acquisition function of the battery management system (BMS) needs to be applied to monitor the changes in the pre-charge current. By collecting the DC bus current, it can be determined whether the pre-charge process is proceeding normally and whether the pre-charge is completed. After judging that the pre-charge is completed, the BMS will control the main positive relay to close and officially output high voltage electricity to the external load.

[0003] Existing BMS generally adopts a current acquisition solution based on a series shunt. However, the current acquisition solution based on a series shunt has certain defects when the vehicle system is undervoltage. When the vehicle is undervoltage, the DC bus voltage will be affected, resulting in inaccurate or invalid voltage values ​​being sent, which in turn causes the BMS to misjudge whether the pre-charging is completed based on the DC bus. In particular, when the bus voltage sends the maximum invalid value, the BMS may mistakenly believe that the pre-charging is complete, thereby controlling the pre-charging relay and the main relay to close at the same time, resulting in a large surge voltage, which can damage the components in the current acquisition circuit. Summary of the invention

[0004] The embodiments of the present invention provide a pre-charging control method, device, terminal equipment and storage medium for a vehicle battery management system, which effectively reduce the risk of BMS pre-charging misjudgment, enhance the reliability and stability of the battery management system, and improve the safety performance of electric vehicles.

[0005] An embodiment of the present invention provides a pre-charging control method for a vehicle battery management system, comprising:

[0006] Get high voltage power-on instruction;

[0007] According to the high voltage power-on instruction, obtaining a startup power supply voltage and a first output voltage of a DC converter;

[0008] When it is determined that the first output voltage or the starting power supply voltage is greater than a first preset voltage, closing the pre-charging relay to pre-charge the DC bus capacitor;

[0009] Monitor the voltage difference between the inside and outside of the battery and the DC bus voltage, and determine whether the DC bus capacitor is pre-charged according to the voltage difference between the inside and outside of the battery and the DC bus voltage;

[0010] When it is confirmed that the pre-charging of the DC bus capacitor is completed, the pre-charging relay is controlled to be disconnected, and the main positive relay is controlled to be closed.

[0011] Further, judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage includes:

[0012] When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is within the first preset voltage range, it is confirmed that the DC bus capacitor pre-charging is completed.

[0013] Further, judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage, further includes:

[0014] When it is determined that the second maintaining time period during which the internal and external voltage difference of the battery is not less than the second preset voltage is not less than the second preset time period, it is confirmed that the DC bus capacitor pre-charging has failed.

[0015] Further, judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage, further includes:

[0016] When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is not within the first preset voltage range, obtaining a second output voltage of the charger;

[0017] determining whether the second output voltage is within a second preset voltage range;

[0018] If yes, it is confirmed that the DC bus capacitor pre-charging is completed;

[0019] If not, it is confirmed that the DC bus capacitor pre-charging has failed.

[0020] Further, after confirming that the DC bus capacitor pre-charging fails, the method further includes:

[0021] Disconnecting the pre-charging relay and obtaining a pre-charging failure count;

[0022] When it is determined that the pre-charging failure count is less than a preset number threshold, the pre-charging failure count is increased by one, and after a preset waiting time, the pre-charging relay is closed again;

[0023] When it is determined that the pre-charging failure count is not less than a preset number threshold, a pre-charging failure alarm is issued.

[0024] Another embodiment of the present invention provides a pre-charging control device for a vehicle battery management system, comprising:

[0025] An instruction acquisition module, used to acquire high voltage power-on instructions;

[0026] A voltage acquisition module, used to acquire a startup power supply voltage and a first output voltage of a DC converter according to the high voltage power-on instruction;

[0027] A pre-charging execution module, configured to close a pre-charging relay when determining that the first output voltage or the starting power supply voltage is greater than a first preset voltage, so as to pre-charge the DC bus capacitor;

[0028] A pre-charge monitoring module is used to monitor the internal and external voltage difference of the battery and the DC bus voltage, and determine whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage;

[0029] The pre-charging completion module is used to control the pre-charging relay to open and the main positive relay to close when confirming that the pre-charging of the DC bus capacitor is completed.

[0030] Furthermore, the pre-charge monitoring module determines whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage, including:

[0031] When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is within the first preset voltage range, it is confirmed that the DC bus capacitor pre-charging is completed.

[0032] Furthermore, the pre-charge monitoring module determines whether the pre-charge of the DC bus capacitor is completed according to the internal and external voltage difference of the battery and the DC bus voltage, and further includes:

[0033] When it is determined that the second maintaining time period during which the internal and external voltage difference of the battery is not less than the second preset voltage is not less than the second preset time period, it is confirmed that the DC bus capacitor pre-charging has failed.

[0034] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, it implements a pre-charging control method for a vehicle battery management system as described in any one of the embodiments.

[0035] Another embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute a pre-charging control method for a vehicle battery management system as described in any one of the above embodiments.

[0036] The following beneficial effects are achieved by implementing the present invention:

[0037] The present invention discloses a pre-charging control method, device, terminal equipment and storage medium of a vehicle battery management system. The method is applied to the battery management system. When a high-voltage power-on instruction is obtained, a starting power supply voltage and a first output voltage of a DC converter are obtained, and when it is determined that the first output voltage or the starting power supply voltage is greater than a first preset voltage, a pre-charging relay is closed to pre-charge a DC bus capacitor. Before pre-charging, the present invention determines whether the current vehicle meets the conditions for starting pre-charging by using the first output voltage and the starting power supply voltage to ensure the safety of the vehicle during the high-voltage power-on process. Secondly, during the pre-charging process, the voltage difference between the inside and outside of the battery and the DC bus voltage are monitored to determine whether the DC bus capacitor is pre-charged, so as to avoid the DC bus voltage being affected when the vehicle system is under-voltage, causing the BMS to misjudge the pre-charging completion, effectively reducing the risk of BMS misjudgment, avoiding the current acquisition circuit from being impacted by a large surge, enhancing the reliability and stability of the battery management system, and improving the safety performance of the electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of a pre-charging control method of a vehicle battery management system provided by one embodiment of the present invention.

[0039] Figure 2 It is a structural schematic diagram of a pre-charging control device of a vehicle battery management system provided by one embodiment of the present invention.

[0040] Figure 3 It is a schematic diagram of the structure of a current acquisition circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0043] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0044] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0045] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0047] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0048] See also Figure 1 , is a flow chart of a pre-charging control method of a vehicle battery management system provided by an embodiment of the present invention, comprising:

[0049] S1. Get high voltage power-on instruction;

[0050] In a preferred embodiment of the present invention, when the vehicle is ready to start or accelerate and a series of safety and preparation conditions have been met, the vehicle controller sends a high-voltage power-on command to the BMS through an internal communication protocol (such as a CAN bus).

[0051] S2. Acquire a startup power supply voltage and a first output voltage of a DC converter according to the high voltage power-on instruction;

[0052] S3. When it is determined that the first output voltage or the starting power supply voltage is greater than a first preset voltage, closing the pre-charging relay to pre-charge the DC bus capacitor;

[0053] In a preferred embodiment of the present invention, the first preset voltage is set to 8V. It can be understood that the DC converter (DC-DC converter) plays an important role in voltage conversion in electric vehicles. This conversion process is crucial for charging the battery, powering the electronic equipment in the vehicle, etc. If the output voltage of the DC converter is stable and greater than the first preset voltage, it can be considered that the power system of the vehicle is in normal working condition, which provides the basic conditions for the pre-charging process. Alternatively, the BMS self-test lead-acid voltage can be used to determine whether the vehicle can start pre-charging. The starting power supply voltage (BMS self-test lead-acid voltage) is the voltage provided by the battery pack when the vehicle starts. This voltage value is directly meaningful for determining whether the vehicle can start pre-charging. Therefore, this embodiment sets a threshold value (first preset voltage) for the starting power supply voltage. Only when the starting power supply voltage is greater than this threshold value will the BMS consider that the condition is met, thereby starting the pre-charging process.

[0054] S4, monitoring the internal and external voltage difference of the battery and the DC bus voltage, and judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage;

[0055] In a preferred embodiment of the present invention, the voltage difference between the inside and outside of the battery refers to the absolute value of the voltage inside the battery minus the voltage outside the battery, and the DC bus voltage can also be replaced by monitoring the DC bus capacitor voltage to determine whether the DC bus capacitor is pre-charged. It can be understood that the DC bus capacitor voltage refers to the voltage across the capacitor, which is usually close to the bus voltage, but may be slightly different due to the energy storage and filtering effects of the capacitor.

[0056] Secondly, in this embodiment, since the current acquisition function of the battery management system (BMS) needs to be applied when monitoring the voltage difference between the inside and outside of the battery and the DC bus voltage, in order to prevent the components of the current acquisition circuit from being damaged by the large surge voltage caused by the BMS pre-charge misjudgment, this embodiment also optimizes the protection circuit of the current acquisition, such as Figure 3 As shown in the figure, on the basis of the original current acquisition circuit, the current acquisition port protection circuit is enhanced, and high-voltage and high-power protection devices, such as transient voltage suppressors (TVS) and gas plasma protectors, are used to achieve rapid protection of the current acquisition circuit and improve the static electricity and surge protection capabilities of the circuit; a filtering link is added to the current acquisition circuit, the circuit layout is optimized, the circuit impedance is reduced, and the impact of large surge voltage on the circuit is reduced, so that when a large surge voltage impact occurs, the devices in the current acquisition circuit are protected from damage, thereby causing current acquisition failure.

[0057] Preferably, judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage includes:

[0058] S41. When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is within the first preset voltage range, confirming that the DC bus capacitor pre-charging is completed.

[0059] In a preferred embodiment of the present invention, the second preset voltage is set to 7V, and the first preset time is set to 120ms. The DC bus capacitor pre-charging is confirmed to be completed by monitoring the voltage difference between the inside and outside of the battery, and when the voltage difference between the inside and outside of the battery is maintained at 7V for more than 120ms and the DC bus voltage is within the first preset voltage range. Compared with the prior art, only the DC bus voltage is used as the single judgment condition to judge whether the pre-charging is completed. In this embodiment, the judgment of the voltage difference between the inside and outside of the battery is added to reduce the misjudgment rate of the BMS.

[0060] Preferably, judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage, further includes:

[0061] S42: When it is determined that the second maintenance time during which the voltage difference between the inside and outside of the battery is not less than the second preset voltage is not less than the second preset time, confirming that the DC bus capacitor pre-charging fails.

[0062] In a preferred embodiment of the present invention, the second preset time is set according to the normal pre-charging time of the DC bus capacitor. It can be understood that when it is monitored that the voltage difference between the inside and outside of the battery cannot be less than the second preset voltage within the time when the pre-charging should be completed, it can be concluded that the pre-charging has failed, and steps S461-S463 are used for processing.

[0063] Preferably, judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage, further includes:

[0064] S43, when it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is not within the first preset voltage range, obtaining a second output voltage of the charger;

[0065] S44, determining whether the second output voltage is within a second preset voltage range;

[0066] S45: If yes, confirm that the DC bus capacitor pre-charging is completed;

[0067] S46: If not, confirm that the DC bus capacitor pre-charging fails.

[0068] In a preferred embodiment of the present invention, since the charger is a power supply device, its main function is to provide electrical energy to batteries or other energy storage devices. During the charging process, the charger will adjust its output voltage and current according to the needs of the charging device. This output voltage is an important indicator of the electrical energy characteristics output by the charger. Therefore, when the charger supplies power to the bus and its connected devices, if the load is stable and there is no other external interference, the voltage of the bus capacitor may be close to or equal to the output voltage of the charger. Therefore, this embodiment further confirms the DC bus voltage by detecting the second output voltage of the charger, and then determines whether the DC bus capacitor has completed pre-charging. The accuracy of the BMS pre-charging completion judgment is further improved.

[0069] Preferably, after confirming that the DC bus capacitor pre-charging fails, the method further includes:

[0070] S461, disconnecting the pre-charging relay and obtaining a pre-charging failure count;

[0071] S462: when it is determined that the pre-charging failure count is less than a preset number threshold, the pre-charging failure count is increased by one, and after a preset waiting time, the pre-charging relay is closed again;

[0072] S463: When it is determined that the pre-charging failure count is not less than a preset number threshold, a pre-charging failure alarm is issued.

[0073] In a preferred embodiment of the present invention, when pre-charging fails, the pre-charging relay needs to be disconnected, and the pre-charging failure count is performed. The pre-charging process is tried again at least 400ms apart, and the count is cleared if successful. If the failure exceeds 4 times, the BMS issues a pre-charging failure alarm to the vehicle. At this time, the BMS needs to shut down all drive circuits and continuously monitor the cell voltage and cell temperature.

[0074] S5. When it is confirmed that the pre-charging of the DC bus capacitor is completed, the pre-charging relay is controlled to be disconnected, and the main positive relay is controlled to be closed.

[0075] The present embodiment provides a pre-charging control method for a vehicle battery management system, which obtains the starting power supply voltage and the first output voltage of the DC converter when obtaining the high-voltage power-on instruction, and closes the pre-charging relay when determining that the first output voltage or the starting power supply voltage is greater than the first preset voltage, so as to pre-charge the DC bus capacitor. Therefore, the present invention effectively ensures the safety of the vehicle during the high-voltage power-on process. Secondly, during the pre-charging process, the voltage difference between the inside and outside of the battery and the DC bus voltage are simultaneously monitored to determine whether the DC bus capacitor is pre-charged, so as to avoid the DC bus voltage being affected when the vehicle system is under-voltage, causing the BMS to misjudge that the pre-charging is completed, effectively reducing the risk of BMS misjudgment, avoiding large surge impacts on the current acquisition circuit, enhancing the reliability and stability of the battery management system, and improving the safety performance of electric vehicles.

[0076] See also Figure 2 , is a schematic structural diagram of a pre-charging control device of a vehicle battery management system provided by an embodiment of the present invention, comprising:

[0077] An instruction acquisition module, used to acquire high voltage power-on instructions;

[0078] A voltage acquisition module, used to acquire a startup power supply voltage and a first output voltage of a DC converter according to the high voltage power-on instruction;

[0079] A pre-charging execution module, configured to close a pre-charging relay when determining that the first output voltage or the starting power supply voltage is greater than a first preset voltage, so as to pre-charge the DC bus capacitor;

[0080] A pre-charge monitoring module is used to monitor the internal and external voltage difference of the battery and the DC bus voltage, and determine whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage;

[0081] The pre-charging completion module is used to control the pre-charging relay to open and the main positive relay to close when confirming that the pre-charging of the DC bus capacitor is completed.

[0082] Preferably, the pre-charge monitoring module determines whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage, including:

[0083] When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is within the first preset voltage range, it is confirmed that the DC bus capacitor pre-charging is completed.

[0084] Preferably, the pre-charge monitoring module determines whether the pre-charge of the DC bus capacitor is completed according to the internal and external voltage difference of the battery and the DC bus voltage, and further includes:

[0085] When it is determined that the second maintaining time period during which the internal and external voltage difference of the battery is not less than the second preset voltage is not less than the second preset time period, it is confirmed that the DC bus capacitor pre-charging has failed.

[0086] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0087] Those skilled in the art can clearly understand that for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0088] Another preferred embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements a pre-charging control method for a vehicle battery management system as described in any one of the above embodiments.

[0089] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0090] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and uses various interfaces and lines to connect various parts of the entire terminal device.

[0091] The memory can be used to store the computer program, and the processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0092] Another preferred embodiment of the present invention provides a storage medium, the storage medium is a computer-readable storage medium, the computer program is stored in the computer-readable storage medium, and the computer program, when executed by the processor, can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0093] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A pre-charging control method for a vehicle battery management system, characterized in that: include: Get high voltage power-on instruction; According to the high voltage power-on instruction, obtaining a startup power supply voltage and a first output voltage of a DC converter; When it is determined that the first output voltage or the starting power supply voltage is greater than a first preset voltage, closing the pre-charging relay to pre-charge the DC bus capacitor; Monitor the voltage difference between the inside and outside of the battery and the DC bus voltage, and determine whether the DC bus capacitor is pre-charged according to the voltage difference between the inside and outside of the battery and the DC bus voltage; When it is confirmed that the pre-charging of the DC bus capacitor is completed, the pre-charging relay is controlled to be disconnected, and the main positive relay is controlled to be closed.

2. A pre-charging control method for a vehicle battery management system as claimed in claim 1, characterized in that: The step of judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage includes: When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is within the first preset voltage range, it is confirmed that the DC bus capacitor pre-charging is completed.

3. A pre-charge control method for a vehicle battery management system as claimed in claim 2, characterized in that: The step of judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage further includes: When it is determined that the second maintaining time period during which the internal and external voltage difference of the battery is not less than the second preset voltage is not less than the second preset time period, it is confirmed that the DC bus capacitor pre-charging has failed.

4. A pre-charging control method for a vehicle battery management system as claimed in claim 3, characterized in that: The step of judging whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage further includes: When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is not within the first preset voltage range, obtaining a second output voltage of the charger; determining whether the second output voltage is within a second preset voltage range; If yes, it is confirmed that the DC bus capacitor pre-charging is completed; If not, it is confirmed that the DC bus capacitor pre-charging has failed.

5. A pre-charge control method for a vehicle battery management system as claimed in claim 4, characterized in that: After confirming that the DC bus capacitor pre-charging fails, the method further includes: Disconnecting the pre-charging relay and obtaining a pre-charging failure count; When it is determined that the pre-charging failure count is less than a preset number threshold, the pre-charging failure count is increased by one, and after a preset waiting time, the pre-charging relay is closed again; When it is determined that the pre-charging failure count is not less than a preset number threshold, a pre-charging failure alarm is issued.

6. A pre-charge control device for a vehicle battery management system, characterized in that: include: An instruction acquisition module, used to acquire high voltage power-on instructions; A voltage acquisition module, used to acquire a startup power supply voltage and a first output voltage of a DC converter according to the high voltage power-on instruction; A pre-charging execution module, configured to close a pre-charging relay when determining that the first output voltage or the starting power supply voltage is greater than a first preset voltage, so as to pre-charge the DC bus capacitor; A pre-charge monitoring module is used to monitor the internal and external voltage difference of the battery and the DC bus voltage, and determine whether the DC bus capacitor is pre-charged according to the internal and external voltage difference of the battery and the DC bus voltage; The pre-charging completion module is used to control the pre-charging relay to open and the main positive relay to close when confirming that the pre-charging of the DC bus capacitor is completed.

7. A pre-charge control device for a vehicle battery management system as claimed in claim 6, characterized in that: The pre-charge monitoring module determines whether the pre-charge of the DC bus capacitor is completed according to the internal and external voltage difference of the battery and the DC bus voltage, including: When it is determined that the first maintenance time during which the internal and external voltage difference of the battery is less than the second preset voltage is not less than the first preset time, and the DC bus voltage is within the first preset voltage range, it is confirmed that the DC bus capacitor pre-charging is completed.

8. A pre-charge control device for a vehicle battery management system as claimed in claim 7, characterized in that: The pre-charge monitoring module determines whether the pre-charge of the DC bus capacitor is completed according to the internal and external voltage difference of the battery and the DC bus voltage, and further includes: When it is determined that the second maintaining time period during which the internal and external voltage difference of the battery is not less than the second preset voltage is not less than the second preset time period, it is confirmed that the DC bus capacitor pre-charging has failed.

9. A terminal device, characterized in that: It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, it implements a pre-charging control method for a vehicle battery management system as described in any one of claims 1 to 5.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute a pre-charging control method for a vehicle battery management system as described in any one of claims 1 to 5.

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