Electric vehicle power supply system, method, device and storage medium

Abstract

The application relates to an electric vehicle power supply system, method, device and storage medium, which receives a low-voltage power-on request sent by a main controller after the whole vehicle is powered off. Based on the low-voltage power-on request, at least two groups of MOS tubes of an internal battery management chip AFE are controlled to be turned on by the BMS, so that at least one battery core in the high-voltage power battery supplies power to low-voltage electrical devices. The above-mentioned method cancels the traditional low-voltage storage battery, reduces the relays, wire harnesses and other auxiliary components of the low-voltage battery, reduces the manufacturing cost and weight of the whole vehicle, improves the endurance potential, and directly calls the energy of the battery core of the high-voltage power battery when the whole vehicle is in sleep state, thereby avoiding the self-discharge loss of the low-voltage battery.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a power supply system, method, device and storage medium for an electric vehicle. Background Art

[0002] Currently, the low-voltage power supply system of electric vehicles generally uses a low-voltage battery as a power source to power low-voltage electrical devices. During normal operation, the high-voltage power battery is stepped down by a step-down DC-DC converter (DCDC) and then connected in parallel with the low-voltage battery to supply power. The electrical devices consume the energy stored in the high-voltage power battery. When the high-voltage system is not operating, the low-voltage battery comes into play to power low-voltage electrical devices. Low-voltage batteries have limited application scenarios, resulting in redundant and wasteful low-voltage power supply systems.

[0003] Related technologies often combine relays with high-voltage power batteries. By controlling the on and off states of the relays, multiple power battery cells can be time-shared, allowing the power battery to power the low-voltage power supply system, eliminating the need for a low-voltage battery. However, the weight and cost of multiple relays and connecting wiring harnesses are not necessarily superior to independent low-voltage battery power supplies. Summary of the Invention

[0004] One of the purposes of the present invention is to provide an electric vehicle power supply system, method, device, vehicle and storage medium, so as to reduce the use of relays and wiring harnesses while achieving the elimination of low-voltage batteries, avoiding redundant waste of low-voltage power supply systems, and reducing the weight and cost of the entire vehicle.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An electric vehicle power supply system, comprising: a high-voltage power battery, a step-down DC / DC converter, a BMS, a vehicle controller, and low-voltage electrical components;

[0007] The high-voltage power battery is connected to the input end of the step-down DC-DC converter, the high-voltage power battery is connected to the BMS, the low-voltage electrical components are connected in parallel with the output end of the step-down DC-DC converter and the output end of the BMS, and the vehicle controller is communicatively connected with the step-down DC-DC converter and the BMS;

[0008] The BMS has an internal integrated AFE, and the AFE has multiple MOS tubes integrated inside.

[0009] The high-voltage power battery integrates multiple battery cells connected in series;

[0010] Each battery cell is connected to a set of MOS tubes;

[0011] The BMS is used to control the conduction of at least two groups of MOS tubes inside the AFE, so that at least one cell in the high-voltage power battery can supply power to the low-voltage electrical device.

[0012] In a possible implementation, each group of MOS transistors includes a high-side MOS transistor and a low-side MOS transistor;

[0013] The first end of the high-side MOS transistor is connected to the positive electrode of the corresponding battery cell, and the second end of the high-side MOS transistor is connected to the positive electrode of the low-voltage electrical device;

[0014] The first end of the low-side MOS transistor is connected to the negative electrode of the corresponding battery cell, and the second end of the low-side MOS transistor is connected to the negative electrode of the low-voltage electrical device.

[0015] In one possible implementation, the BMS is also used to automatically switch to the spare battery pack and report a fault code to the vehicle controller when the AFE detects an overcurrent or short circuit in the MOS tube.

[0016] In one possible implementation, the step-down DCDC is used to step down the high voltage electricity output by the high voltage power battery to supply power to the low voltage electrical devices.

[0017] A method for powering an electric vehicle, using the BMS in any one of the above-mentioned electric vehicle power supply systems, the method comprising:

[0018] After the vehicle is powered off, it receives a low-voltage power-on request from the main controller;

[0019] Based on the low-voltage power-on request, the BMS controls at least two groups of MOS tubes of the internal battery management chip AFE to be turned on, so that at least one cell in the high-voltage power battery supplies power to the low-voltage electrical device.

[0020] In one possible implementation, the method further includes:

[0021] After the BMS starts the battery cell inspection function in sleep mode, sleep feedback information is sent to the main controller, so that the main controller controls the step-down DCDC to stop power supply.

[0022] In one possible implementation, the method further includes:

[0023] After the vehicle is powered on, receiving a power supply switching instruction sent by the main controller;

[0024] Based on the power supply switching instruction, the MOS tube in the AFE is turned off, and power supply to the low-voltage electrical device is stopped.

[0025] In one possible implementation, the method further includes:

[0026] After the BMS turns on the battery cell inspection function, the AFE is controlled to detect the voltage of the current power supply battery cell according to a preset period;

[0027] When the voltage of the current power supply cell is lower than a preset discharge end threshold, the AFE triggers a hardware interrupt to wake up the BMS;

[0028] After the BMS collects all the voltages of the high-voltage power battery, it selects the battery cell group with the highest voltage priority as the next group of power supply cells;

[0029] The BMS controls the AFE to disconnect the current power supply circuit and turn on the MOS tubes corresponding to the next group of power supply cells, so that the next group of power supply cells can supply power to the low-voltage electrical devices.

[0030] A BMS includes: a storage unit, a processing unit;

[0031] The storage unit stores computer-executable instructions;

[0032] The processing unit executes the computer-executable instructions stored in the storage unit, so that the processing unit performs any one of the above methods.

[0033] A computer-readable storage medium stores computer-executable instructions, which are used to implement any of the above methods when executed by a processor.

[0034] A computer program product comprises a computer program, which implements any of the above methods when executed by a processor.

[0035] Beneficial effects of the present invention:

[0036] This solution connects the high-voltage power battery to the step-down DC-DC converter and the BMS. The step-down DC-DC converter and BMS are connected in parallel to power low-voltage electrical devices. The vehicle controller coordinates power mode switching. The step-down DC-DC converter provides power during operation, while the BMS controls the cells through its integrated AFE during dormancy, directly supplying power to the low-voltage system. The vehicle controller schedules power supply circuit switching during the start / stop phase. By eliminating the low-voltage battery, lightweighting and cost reduction are achieved. The dual-power supply redundancy design improves system reliability. Dynamic cell switching and balancing management extend the life of the power battery. A low-power sleep mode optimizes standby range, effectively addressing the issues of redundant waste, high self-discharge, and short lifespan in traditional low-voltage power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The electric vehicle power supply system architecture diagram provided for this application;

[0038] Figure 2 The internal structure diagram of the high-voltage power battery provided for this application;

[0039] Figure 3 Schematic diagram of the electric vehicle power supply method provided in this embodiment Figure 1 ;

[0040] Figure 4 Schematic diagram of the electric vehicle power supply method provided in this embodiment Figure 2 ;

[0041] Figure 5 Schematic diagram of the electric vehicle power supply method provided in this embodiment Figure 3 ;

[0042] Figure 6 A schematic diagram of the BMS structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0044] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0045] Figure 1 The electric vehicle power supply system architecture diagram provided for this application is as follows: Figure 1As shown, the system includes 1-high-voltage power battery, 2-step-down DC-DC, 3-BMS, 4-low-voltage electrical components, and 5-VCU (vehicle control unit). 1-high-voltage power battery is connected to the input of 2-step-down DC-DC via a high-voltage power bus, transmitting the high-voltage electricity generated by 1-high-voltage power battery. Another connection line between 1-high-voltage power battery and 2-step-down DC-DC is used to transmit control signals, such as status information fed back by 2-step-down DC-DC to 1-high-voltage power battery. 1-high-voltage power battery is connected to 3-BMS. Of the two connection lines between 1-high-voltage power battery and 3-BMS, one is used by 1-high-voltage power battery to transmit battery cell voltage, temperature, and other information to 3-BMS, while the other connection is used by 3-BMS to transmit drive signals to battery cell-related control components to achieve battery cell control operations. The 4-low-voltage electrical devices are connected in parallel to the output of the 2-buck DC-DC converter and the output of the 3-BMS via low-voltage power lines. One of the connecting lines between the 2-buck DC-DC converter and the 4-low-voltage electrical devices is used by the 2-buck DC-DC converter to convert high-voltage electricity into low-voltage electricity, which is then supplied to the 4-low-voltage electrical devices through this line to meet their operating voltage requirements. The other connecting line is used to return the current passing through the 4-low-voltage electrical devices to the 2-buck DC-DC converter, forming a complete current path. The two connecting lines between the 3-BMS and the 4-low-voltage electrical devices are used by the 3-BMS to control the battery cells through its internal AFE chip and other devices, extracting energy from the cells and supplying power to the 4-low-voltage electrical devices through this line. The other connecting line also forms a current loop, allowing the current drawn from the cells to pass through the 4-low-voltage electrical devices and then return to the cell circuit controlled by the 3-BMS through this loop line, ensuring a complete current path when the 3-BMS controls the cells to supply power to the 4-low-voltage electrical devices. 5-VCU communicates with 2-buck DCDC and 3-BMS.

[0046] Among them, the BMS integrates AFE inside, and the AFE integrates multiple groups of MOS tubes inside. Figure 2 The internal structure diagram of the high-voltage power battery provided for this application is as follows: Figure 2 As shown, 1-the high-voltage power battery integrates multiple battery cells connected in series.

[0047] Each battery cell is connected to a group of MOS tubes. Optionally, each group of MOS tubes includes a high-side MOS tube and a low-side MOS tube. The first end of the high-side MOS tube is connected to the positive electrode of the corresponding battery cell, and the second end of the high-side MOS tube is connected to the positive electrode of the low-voltage electrical device. The first end of the low-side MOS tube is connected to the negative electrode of the corresponding battery cell, and the second end of the low-side MOS tube is connected to the negative electrode of the low-voltage electrical device.

[0048] In one possible implementation, 4 low-voltage electrical devices are simultaneously connected to the output of 2 step-down DCDCs and the output of 3 BMSs, forming a dual-parallel power supply topology of "DCDC main supply + BMS backup".

[0049] Specifically, 1-the high-voltage power battery is connected to the AFE inside 3-BMS through the battery cell sampling harness and MOS drive line to realize battery cell status monitoring and power supply path control.

[0050] 5-VCU is connected to the communication interface of 3-BMS through CAN bus / hard-wire enable signal, and sends control instructions such as "low-voltage power-on request" and "power supply switching instruction" (for example, triggering BMS to start AFE power supply when the vehicle is powered off);

[0051] 5-VCU is connected to the communication interface of 2-buck DCDC through the CAN bus / hard-wire enable signal, and sends control commands such as "wake up DCDC" and "stop DCDC" (for example, wake up DCDC and restore power supply when the vehicle is started);

[0052] 5-VCU receives status signals such as "AFE power supply stability" and "battery cell voltage abnormality" from 3-BMS through the CAN bus to achieve closed-loop control.

[0053] 3-BMS receives control instructions from 5-VCU and triggers the cell switching logic of the AFE chip;

[0054] 3-BMS feeds back status signals such as "AFE power supply stability" and "cell voltage threshold warning" to 5-VCU, and cooperates with 5-VCU to complete power supply mode switching;

[0055] The AFE chip and the battery cells of the high-voltage power battery exchange data and control signals in real time through the sampling line (voltage / temperature) + MOS drive line (switch control).

[0056] 2-Buck DCDC receives the wake-up / stop command from 5-VCU and controls its own start and stop;

[0057] The 2-step-down DCDC feeds back status signals such as "DCDC output voltage is stable" and "DCDC fault" to the 5-VCU, assisting the 5-VCU in determining power supply safety.

[0058] Figure 3 Schematic diagram of the electric vehicle power supply method provided in this embodiment Figure 1 ,like Figure 3 As shown, the method should be used in the aforementioned electric vehicle power supply system, which is a BMS. The method mainly includes:

[0059] S301: After the vehicle is powered off, a low-voltage power-on request is received from a main controller.

[0060] In this step, when an electric vehicle stops operating, the vehicle controller responds to the vehicle power-off signal and controls the powering off of most controllers. Traditional solutions rely on independent low-voltage batteries (such as lead-acid batteries) to maintain power for low-voltage loads (such as the anti-theft system, T-BOX, and door controllers). However, low-voltage batteries have inherent drawbacks such as severe self-discharge. This step uses the vehicle controller to control the power-off sequence, first safely disconnecting the high-voltage circuit (disconnecting the high-voltage power battery main relay to ensure high-voltage side safety), then triggering the BMS to initiate "cell-to-low-voltage" mode, replacing the traditional low-voltage battery with cells from the high-voltage power battery, thus eliminating the defects of the low-voltage battery at the root.

[0061] Specifically, the main controller first shuts down non-essential high-voltage loads (such as the drive motor and air conditioning compressor) and disconnects the high-voltage main relay of the high-voltage power battery (a standard safety feature of the high-voltage circuit, not explicitly marked in the attached figure). This disconnects the high-voltage power bus from external power, leaving only the BMS low-voltage control power supply. Once the high-voltage circuit is safely de-energized, the vehicle controller sends a "low-voltage power-on request" (which can be defined as a dedicated CAN message, such as frame ID 0x123, with a request flag bit in the data field) to the BMS via the CAN bus or a hard-wired enable signal.

[0062] Among them, the BMS is in a "low-power standby wake-up" state (only the communication module is kept running) when the vehicle is powered off. When it detects a "low-voltage power-on request" from the vehicle controller, it activates the internal control logic to prepare for the subsequent MOS tube control of the AFE chip.

[0063] S302: Based on the low-voltage power-on request, the BMS controls at least two groups of MOS tubes of the internal battery management chip AFE to be turned on, so that at least one cell in the high-voltage power battery supplies power to the low-voltage electrical device.

[0064] In this step, in traditional solutions, low-voltage loads are powered by a single path: "high-voltage power battery → DCDC → low-voltage load" (during driving) or "low-voltage battery → low-voltage load" (after the DCDC is dormant). To eliminate the low-voltage battery and its associated components, reducing costs and weight, the high-voltage power battery cells are used to directly power the low-voltage load after the DCDC is dormant, completely eliminating the need for a separate low-voltage battery.

[0065] Specifically, after the BMS receives the low-voltage power-on request sent by the vehicle controller, it implements the "high-voltage power battery cell directly supplies the low-voltage load" through three steps: cell group selection → MOS tube conduction → power supply circuit establishment.

[0066] The BMS pre-stores the number of cells in the high-voltage power battery (e.g., 10 cells in series) and the nominal voltage of each cell (e.g., 3.7V ternary lithium), and automatically calculates the number of cells in series to meet the requirements of the low-voltage system (e.g., a 12V system requires 3 to 4 cells in series, 3.7V×3=11.1V≈12V, using the cell voltage fluctuation tolerance or built-in micro voltage regulator).

[0067] Specific cell selection rules may include: cells in the "middle range" of voltage (avoiding fully charged / low-charged cells to reduce balancing pressure); and cell groups with the least number of historical discharges (balancing the cycle life of each cell).

[0068] The BMS sends instructions to the internal AFE. Each cell in the AFE corresponds to a set of high-side MOS transistors (controlling the positive pole of the cell to the low-voltage positive pole) and low-side MOS transistors (controlling the negative pole of the cell to the low-voltage negative pole). Take "selecting cells 3 and 6 in series for power supply" as an example:

[0069] The high-side MOS tube of the third cell is controlled to be turned on so that its positive electrode is connected to the positive bus of the low-voltage electrical device. The low-side MOS tube of the sixth cell is controlled to be turned on so that its negative electrode is connected to the negative bus of the low-voltage electrical device. After the two groups of MOS tubes are turned on, the series voltage of the third to sixth cells (a total of 4 cells) (3.7V×4=14.8V; if 12V is required, the AFE built-in voltage regulator or direct adaptation to the load voltage tolerance range is used) directly supplies power to the low-voltage electrical device.

[0070] The electric vehicle power supply method provided in this application receives a low-voltage power-on request sent by the main controller after the entire vehicle is powered off. Based on the low-voltage power-on request, the BMS controls at least two groups of MOS tubes of the internal battery management chip AFE to turn on, so that at least one cell in the high-voltage power battery supplies power to the low-voltage electrical device. The above method eliminates the traditional low-voltage battery, reduces the relays, wiring harnesses and other auxiliary components of the low-voltage battery, reduces the manufacturing cost and weight of the entire vehicle, improves the endurance potential, and directly calls on the cell energy of the high-voltage power battery when the entire vehicle is dormant, avoiding the self-discharge loss of the low-voltage battery.

[0071] Figure 4 Schematic diagram of the electric vehicle power supply method provided in this embodiment Figure 2 ,like Figure 4 As shown, the method further includes:

[0072] S401: After the vehicle is powered on, a power supply switching instruction sent by a main controller is received.

[0073] Vehicle power-up (e.g., key start, remote wakeup) marks the transition from "sleep standby" to "operational readiness." During sleep mode, low-voltage loads only need to maintain low-power devices like security (e.g., T-BOX, anti-theft controller) and communications. During operation, low-voltage loads must support high-power devices (hundreds of watts) such as air conditioning, entertainment systems, and electric power steering. In traditional low-voltage power supply solutions (relying on a separate low-voltage battery), the DC-DC (direct current-delivery) system (DCDC) activates upon vehicle power-up. However, the DCDC and LV battery are connected in parallel for a long period of time (without active disconnection logic). This voltage difference between the DCDC output and the LV battery causes "circulation current" (e.g., if the DCDC output is 14V and the LV battery is 12V, the battery continues to charge when connected in parallel, wasting energy). The LV battery is independently managed by its own BMS and lacks coordination with the vehicle's VCU. This makes it impossible to precisely synchronize the "DCDC activation → battery shutdown" sequence, which can easily lead to voltage fluctuations at the load end (e.g., the LV battery continues to discharge at the moment the DCDC activates, causing voltage spikes). The main controller can lead the transmission of the mode switching command of "sleep power supply (BMS battery cell direct supply) → running power supply (DCDC main supply)" to ensure the timing safety and seamless power supply of the switching process. That is, first let the DCDC output low-voltage power stably, and then cut off the direct supply of the BMS battery cell to avoid power outage of the low-voltage load or conflict between the two power supplies in parallel.

[0074] Specifically, the vehicle controller first wakes up the step-down DCDC. After the step-down DCDC starts and stably outputs low-voltage electricity, it sends a switching instruction to the BMS to ensure that the step-down DCDC power supply is stable before cutting off the direct supply of battery cells to the BMS, eliminating the circulating current and voltage fluctuations of the dual power supplies in parallel.

[0075] S402: Based on the power supply switching instruction, the MOS tube in the AFE is turned off to stop supplying power to the low-voltage electrical components.

[0076] During this step, when the vehicle is operating, the power demand of low-voltage loads increases significantly (e.g., the air conditioning compressor and electric power steering, which can reach hundreds of watts). However, the "direct cell supply" implemented by the BMS through the AFE's MOSFET can only meet the power needs of low-power loads in dormant mode (e.g., T-BOX and anti-theft controller, which have a power <10W). Continuing to supply high loads during operation will cause a single cell or a small number of cells to discharge continuously at high currents, accelerating cell aging. Under high loads, the cell voltage will drop rapidly, causing undervoltage faults in the low-voltage system (e.g., an ECU restart). Therefore, after the step-down DC-DC converter takes over power, the BMS's direct cell supply circuit is promptly disconnected, allowing the high-voltage power battery's energy to be transmitted through the normal "step-down DC-DC converter" path to low-voltage loads. This ensures that the high power demand during operation is met while protecting the cell's lifespan.

[0077] Specifically, after receiving the power supply switching instruction sent by the main controller, the BMS disconnects the conductive MOS tube and cuts off the direct supply circuit of the BMS battery cell.

[0078] The electric vehicle power supply method provided in this application receives a power supply switching instruction sent by the main controller after the vehicle is powered on. Based on the power supply switching instruction, the MOS tube in the AFE is disconnected, and power supply to the low-voltage electrical components is stopped. Through the above method, the control pain points of the traditional low-voltage power supply mode switching without coordination and easy conflict are solved, as well as the physical pain points that the direct supply of battery cells cannot meet the high load of the running state and accelerates the aging of the battery cells. It not only ensures the life of the battery cells, but also reduces redundant hardware and control logic, reducing the cost of the whole vehicle.

[0079] Figure 5 Schematic diagram of the electric vehicle power supply method provided in this embodiment Figure 3 ,like Figure 5 As shown, the method further includes:

[0080] S501: After the BMS turns on the battery cell inspection function, the AFE is controlled to detect the voltage of the current power supply battery cell according to a preset cycle.

[0081] In this step, during the vehicle's dormant phase (where only the BMS's AFE supplies power to low-voltage loads), the voltage status of the current power supply cell is continuously monitored, providing an early warning of undervoltage risks and providing data for subsequent cell switching. Traditional low-voltage power supplies rely on independent lead-acid / lithium batteries, whose voltage monitoring is performed independently by the battery's own BMS. This requires the additional deployment of a voltage sampling harness, protection board, and communication module for the low-voltage battery, increasing the cost and weight of the vehicle. The low-voltage battery BMS communicates with the entire controller via CAN (message period ≥ 200ms), resulting in a high undervoltage warning delay, which can easily lead to deep discharge of the cell. Therefore, after the BMS activates the cell inspection function, it can control the AFE to detect the voltage of the current power supply cell at a preset period.

[0082] S502: When the voltage of the current power supply cell is lower than a preset discharge end threshold, the AFE triggers a hardware interrupt to wake up the BMS.

[0083] In this step, when the voltage of the current power supply cell drops to the discharge cut-off threshold (such as 2.8V for ternary lithium and 2.5V for lithium iron phosphate), the BMS is quickly awakened to perform cell switching to avoid deep discharge of the cell.

[0084] S503: After the BMS collects all the voltages of the high-voltage power batteries, it selects the battery cell group with the highest voltage priority as the next group of power supply cells.

[0085] In this step, in order to ensure normal power supply to the buns, a group of cells with sufficient voltage and balanced lifespan is selected from the multiple cells as the next group of power supply, avoiding excessive discharge of a single cell and extending the life of the entire high-voltage power battery pack.

[0086] For example, an intelligent priority algorithm may be used, with the first priority being that the voltage is within ±5% of the average voltage of the battery cell group (avoiding selection of fully charged or undercharged cells to reduce balancing pressure);

[0087] Second priority: Minimize the cumulative number of discharges (balance the number of cycles for each cell so that the difference in the number of discharges for the entire pack is less than 10%).

[0088] S504: The BMS controls the AFE to disconnect the current power supply circuit and turn on the MOS tubes corresponding to the next group of power supply cells, so that the next group of power supply cells can supply power to the low-voltage electrical devices.

[0089] In this step, while disconnecting the current power supply cell, the MOS tubes of the next group of cells are quickly turned on to achieve "non-stop switching" and ensure the continuous operation of low-voltage loads (such as T-BOX and anti-theft controller).

[0090] The electric vehicle power supply method provided by the present application, after the BMS turns on the battery cell inspection function, controls the AFE to detect the voltage of the current power supply battery cell according to a preset cycle, and when the voltage of the current power supply battery cell is lower than the preset discharge end threshold, the AFE triggers a hardware interrupt to wake up the BMS. After the BMS collects all the voltages of the high-voltage power battery, it selects the battery cell group with the highest voltage priority as the next group of power supply batteries. The BMS controls the AFE to disconnect the current power supply circuit and turn on the MOS tube corresponding to the next group of power supply batteries, so that the next group of power supply batteries can supply power to low-voltage electrical devices. Through the above method, the deep discharge of the battery cell is avoided, the battery cell life is maximized, the continuity of the low-voltage power supply is guaranteed, the low-voltage battery and the attached BMS are eliminated, which not only reduces weight but also reduces costs, and completely eliminates the vicious cycle of "undervoltage power off → load restart → increased power consumption" of the traditional low-voltage battery, and the reliability of the vehicle electrical system is improved.

[0091] Figure 6 The BMS structure diagram provided in the embodiment of this application is as follows: Figure 6 As shown, the BMS 600 includes: a storage unit 602, a processing unit 601;

[0092] The storage unit 602 stores computer-executable instructions;

[0093] The processing unit 601 executes the computer-executable instructions stored in the storage unit 602 , so that the processing unit 601 performs the above method.

[0094] Optionally, the BMS further includes a communication component 603 , wherein the processing unit 601 , the storage unit 602 and the communication component 603 are connected via a bus 604 .

[0095] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly executed by a hardware processor or by a combination of hardware and software modules within the processor.

[0096] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage.

[0097] A bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0098] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0099] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0100] The readable storage medium may be implemented by any type of volatile or non-volatile memory device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0101] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0102] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0103] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0104] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0105] If a function is implemented as 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 invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0106] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0107] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. An electric vehicle power supply system, characterized in that: include: High-voltage power batteries, step-down DC-DC converters (DCDC), battery management controllers (BMS), vehicle controllers, and low-voltage electrical devices; The high-voltage power battery is connected to the input end of the step-down DC-DC converter DCDC, the high-voltage power battery is connected to the BMS, the low-voltage electrical components are connected in parallel with the output end of the step-down DC-DC converter DCDC and the output end of the BMS, the vehicle controller is communicatively connected to the step-down DC-DC converter DCDC and the BMS, and the vehicle controller is configured to send a low-voltage power-on request to the BMS after the vehicle is powered off, and send a power supply switching instruction to the BMS after the vehicle is powered on; The BMS internally integrates a battery management chip AFE, and the AFE internally integrates multiple groups of metal-oxide-semiconductor field-effect transistors MOS tubes; The high-voltage power battery integrates multiple battery cells connected in series; Each battery cell is independently connected to a set of MOS tubes; The BMS is used to control at least two groups of MOS tubes in the AFE to be turned on based on the low-voltage power-on request, so that at least one cell in the high-voltage power battery supplies power to the low-voltage electrical device; Each group of MOS tubes includes a high-side MOS tube and a low-side MOS tube; The first end of the high-side MOS transistor is connected to the positive electrode of the corresponding battery cell, and the second end of the high-side MOS transistor is connected to the positive electrode of the low-voltage electrical device; The first end of the low-side MOS transistor is connected to the negative electrode of the corresponding battery cell, and the second end of the low-side MOS transistor is connected to the negative electrode of the low-voltage electrical device.

2. The system according to claim 1, wherein: The BMS is also used to automatically switch to the spare battery pack and report a fault code to the vehicle controller when the AFE detects an overcurrent or short circuit in the MOS tube.

3. The system according to claim 1, wherein: The step-down DC-DC converter DCDC is used to step down the high voltage electricity output by the high voltage power battery to supply power to the low voltage electrical devices.

4. A method for powering an electric vehicle, characterized in that: A battery management controller (BMS) used in an electric vehicle power supply system according to any one of claims 1 to 3, the method comprising: After the vehicle is powered off, it receives a low-voltage power-on request from the main controller; Based on the low-voltage power-on request, the BMS controls at least two groups of metal-oxide-semiconductor field-effect transistors (MOS) of the internal battery management chip (AFE) to turn on, so that at least one cell in the high-voltage power battery supplies power to the low-voltage electrical device.

5. The method according to claim 4, characterized in that The method further comprises: After the BMS starts the battery cell inspection function in sleep mode, sleep feedback information is sent to the main controller, so that the main controller controls the step-down DC-DC converter DCDC to stop supplying power.

6. The method according to claim 4, characterized in that The method further comprises: After the vehicle is powered on, receiving a power supply switching instruction sent by the main controller; Based on the power supply switching instruction, the MOS tube in the AFE is turned off, and power supply to the low-voltage electrical device is stopped.

7. The method according to claim 5, characterized in that The method further comprises: After the BMS turns on the battery cell inspection function, the AFE is controlled to detect the voltage of the current power supply battery cell according to a preset period; When the voltage of the current power supply cell is lower than a preset discharge end threshold, the AFE triggers a hardware interrupt to wake up the BMS; After the BMS collects all the voltages of the high-voltage power battery, it selects the battery cell group with the highest voltage priority as the next group of power supply cells; The BMS controls the AFE to disconnect the current power supply circuit and turn on the MOS tubes corresponding to the next group of power supply cells, so that the next group of power supply cells can supply power to the low-voltage electrical devices.

8. A BMS, characterized in that: include: Storage unit, processing unit; The storage unit stores computer-executable instructions; The processing unit executes the computer-executable instructions stored in the storage unit, so that the processing unit performs the method according to any one of claims 4 to 7.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method according to any one of claims 4 to 7.

10. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 4 to 7 is implemented.

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