Low-voltage power supply system and vehicle control system

Abstract

According to the low-voltage power supply system and the vehicle control system, a low-voltage battery cell module and a high-voltage battery cell module are integrated into the same battery pack, the low-voltage battery cell module directly supplies power to low-voltage components of a whole vehicle, the battery efficiency is high, a bidirectional DCDC converter is arranged between the low-voltage battery cell module and the high-voltage battery cell module, and the battery efficiency is high. The low-voltage battery cell module can charge the high-voltage battery cell module, the high-voltage battery cell module can charge the low-voltage battery cell module, the low-voltage battery cell module and the high-voltage battery cell module can share one set of battery management system, the cost is reduced, and the safety is improved. The whole vehicle control system obtains the working modes, determined by the battery management system, of the low-voltage battery cell module and the high-voltage battery cell module to control the working state of the bidirectional DCDC converter so as to achieve working in different modes.

Description

Technical Field

[0001] This application relates to the technical field of low-voltage power supply for vehicles, and particularly to a low-voltage power supply system and a vehicle control system. Background Art

[0002] The traditional 12V automotive power supply system is supplied by a separate battery pack, and an independent detection and management system needs to be arranged for the 12V battery pack, resulting in a relatively high system cost. The current mainstream solutions for the 12V battery pack are lead-acid batteries or lithium iron phosphate batteries. Lead-acid batteries have disadvantages such as short lifespan, high cost, and low efficiency. Lithium iron phosphate batteries have disadvantages such as high cost, low efficiency, and low safety. Summary of the Invention

[0003] The purpose of this application is to overcome the deficiencies of the existing 12V power supply system, such as high cost, low efficiency, and low safety, and provide a low-voltage power supply system and a vehicle control system that integrate low-voltage battery cells into high-voltage battery cells to reduce costs and improve efficiency and safety.

[0004] The technical solution of this application provides a low-voltage power supply system, including:

[0005] A battery pack provided with a low-voltage battery cell module and a high-voltage battery cell module, where the low-voltage battery cell module is used to directly supply power to the low-voltage components of the whole vehicle;

[0006] A bidirectional DCDC converter electrically connected to both the low-voltage battery cell module and the high-voltage battery cell module, used to achieve bidirectional charging and discharging between the low-voltage battery cell module and the high-voltage battery cell module;

[0007] A battery management system electrically connected to both the low-voltage battery cell module and the high-voltage battery cell module, used to collect the low-voltage battery cell parameters of the low-voltage battery cell module and the high-voltage battery cell parameters of the high-voltage battery cell module, and determine the current working mode of the power supply system according to the low-voltage battery cell parameters and the high-voltage battery cell parameters.

[0008] Further, the battery management system includes:

[0009] A low-voltage slave control unit electrically connected to the low-voltage battery cell module, used to collect the low-voltage battery cell parameters;

[0010] A high-voltage slave control unit electrically connected to the high-voltage battery cell module, used to collect the high-voltage battery cell parameters;

[0011] A master control unit electrically connected to the low-voltage slave control unit and the high-voltage slave control unit, used to determine the current working mode of the power supply system according to the low-voltage battery cell parameters and the high-voltage battery cell parameters.

[0012] Further, the master control unit includes:

[0013] A low - voltage acquisition module, electrically connected to the low - voltage slave control unit, is used to call the low - voltage battery cell parameters, where the low - voltage battery cell parameters include low - voltage SOC, low - voltage voltage, and low - voltage current;

[0014] A high - voltage acquisition module, electrically connected to the high - voltage slave control unit, is used to call the high - voltage battery cell parameters, where the high - voltage battery cell parameters include high - voltage SOC, high - voltage voltage, and high - voltage current;

[0015] A control algorithm module, electrically connected to the low - voltage acquisition module and the high - voltage acquisition module, is used to determine the low - voltage working state of the low - voltage battery cell module according to the low - voltage SOC, the low - voltage voltage, and the low - voltage current, and determine the high - voltage working state of the high - voltage battery cell module according to the high - voltage SOC, the high - voltage voltage, and the high - voltage current.

[0016] Further, the master control unit further includes:

[0017] A communication module, electrically connected to the control algorithm module, the low - voltage acquisition module, and the high - voltage acquisition module, is used to send the low - voltage battery cell parameters, the high - voltage battery cell parameters, the low - voltage working state, and the high - voltage working state to the vehicle control system.

[0018] Further, a pressure sensor is installed in the low - voltage battery cell module, and the master control unit further includes a low - voltage control module electrically connected to the communication module, which is used to collect the pressure data of the pressure sensor.

[0019] Further, the low - voltage battery cell parameters further include low - voltage battery cell temperature, and the high - voltage battery cell parameters further include high - voltage battery cell temperature;

[0020] The communication module is also used to send the low - voltage battery cell temperature, the high - voltage battery cell temperature, and the pressure data to the thermal management system and the battery safety system.

[0021] The technical solution of the present application also provides a vehicle control system, including a vehicle control system and the low - voltage power supply system as described above;

[0022] The vehicle control system is electrically connected to the battery management system and the bidirectional DCDC converter, and is used to control the working state of the bidirectional DCDC converter according to the current working mode of the power supply system.

[0023] Further, the current working mode of the power supply system includes the low - voltage working state of the low - voltage battery cell module and the high - voltage working state of the high - voltage battery cell module;

[0024] The vehicle control system is specifically used for:

[0025] When both the low-voltage working state and the high-voltage working state are discharge states, control the bidirectional DCDC converter to output forward;

[0026] When the low-voltage working state is a discharge state and the high-voltage working state is a non-working state, control the bidirectional DCDC converter to standby;

[0027] When the low-voltage working state is a discharge state and the high-voltage working state is a charging state, control the bidirectional DCDC converter to output in inversion.

[0028] Furthermore, it further includes a thermal management system and a battery safety system. Both the thermal management system and the battery safety system are electrically connected to the battery management system, and are used to control battery thermal management and battery safety management according to the low-voltage cell parameters and the high-voltage cell parameters.

[0029] After adopting the above technical solutions, the following beneficial effects are obtained:

[0030] This application integrates the low-voltage cell module and the high-voltage cell module into the same battery pack. The low-voltage cell module directly supplies power to the low-voltage parts of the whole vehicle, and the battery efficiency is relatively high. A bidirectional DCDC converter is provided between the low-voltage cell module and the high-voltage cell module, which can realize charging from the low-voltage cell module to the high-voltage cell module and charging from the high-voltage cell module to the low-voltage cell module. The low-voltage cell module and the high-voltage cell module can share a set of battery management systems, which not only reduces costs but also improves safety. Description of the Drawings

[0031] Referring to the drawings, the disclosure of this application will become easier to understand. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the protection scope of this application. In the figures:

[0032] Figure 1 is a schematic structural diagram of a low-voltage power supply system in an embodiment of this application;

[0033] Figure 2 is a schematic structural diagram of a vehicle control system in an embodiment of this application.

[0034] Correspondence Table of Reference Numerals:

[0035] Low-voltage cell module 01: Pressure sensor 11;

[0036] High-voltage cell module 02, Bidirectional DCDC converter 03;

[0037] Battery management system 04: Low-voltage slave control unit 41, High-voltage slave control unit 42, Main control unit 43, Low-voltage acquisition module 431, High-voltage acquisition module 432, Control algorithm module 433, Communication module 434, Low-voltage control module 435;

[0038] The low-voltage components of the whole vehicle 10, the whole vehicle control system 20, the thermal management system 30, and the battery safety system 40. Specific embodiments

[0039] The following further illustrates the specific embodiments of the present application in conjunction with the accompanying drawings.

[0040] It is easy to understand that according to the technical solution of the present application, under the condition of not changing the essence of the present application, there are various structural ways and implementation ways that can be mutually replaced by those of ordinary skill in the art. Therefore, the following specific embodiments and the accompanying drawings are only exemplary descriptions of the technical solution of the present application, and should not be regarded as the whole of the present application or as a limitation or restriction on the technical solution of the application.

[0041] The orientation terms such as up, down, left, right, front, back, front side, back side, top, bottom, etc. mentioned or likely to be mentioned in this specification are defined relative to the structures shown in the respective drawings. They are relative concepts, and thus may change accordingly depending on their different positions and different usage states. Therefore, these or other orientation terms should not be construed as restrictive terms. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0043] The low-voltage power supply system in the embodiment of the present application, as Figure 1 shown, includes:

[0044] A battery pack provided with a low-voltage cell module 01 and a high-voltage cell module 02, and the low-voltage cell module 01 is used to directly supply power to the low-voltage components of the whole vehicle 10;

[0045] A bidirectional DCDC converter 03 electrically connected to both the low-voltage cell module 01 and the high-voltage cell module 02, which is used to realize the bidirectional charging and discharging between the low-voltage cell module 01 and the high-voltage cell module 02;

[0046] A battery management system 04 electrically connected to both the low-voltage battery cell module 01 and the high-voltage battery cell module 02, which is used to collect the low-voltage battery cell parameters of the low-voltage battery cell module 01 and the high-voltage battery cell parameters of the high-voltage battery cell module 02, and determine the current working mode of the power supply system according to the low-voltage battery cell parameters and the high-voltage battery cell parameters.

[0047] In the embodiment of the present application, the low-voltage battery cell module 01 is integrated into the battery pack provided with the high-voltage battery cell module 02. The high-voltage battery cell module 02 includes a plurality of battery cells connected in series to output a high-voltage current. The low-voltage battery cell module 01 consists of a small number of battery cells connected in series to output a low-voltage current. Taking a 12V voltage as an example, it can be composed of 4 battery cells of 3V connected in series. The low-voltage battery cell module 01 and the high-voltage battery cell module 02 are integrated in one battery pack, reducing the setting of the low-voltage battery pack, and the two can share the existing battery management system 04 of the high-voltage battery pack, reducing costs and also reducing the number of vehicle parts.

[0048] The positive and negative electrodes of the low-voltage battery cell module 01 are directly connected to the vehicle low-voltage parts 10 through fuses, and can directly supply power to the vehicle low-voltage parts 10. A bidirectional DCDC converter 03 is connected between the low-voltage battery cell module 01 and the high-voltage battery cell module 02, which can convert the low voltage of the low-voltage battery cell module 01 into high voltage to charge the high-voltage battery cell module 02, or convert the high voltage of the high-voltage battery cell module 02 into low voltage to charge the low-voltage battery cell module 01 or supply power to the vehicle low-voltage parts 10. The bidirectional DCDC converter 03 can realize the conversion of electric energy between the low-voltage battery cell module 01 and the high-voltage battery cell module 02, thereby improving the power supply efficiency.

[0049] The battery management system (BMS) 04 is used to collect the low-voltage battery cell parameters and the high-voltage battery cell parameters. The low-voltage battery cell parameters may include low-voltage SOC, low-voltage voltage, low-voltage current, and low-voltage battery cell temperature. The high-voltage battery cell parameters may include high-voltage SOC, high-voltage voltage, high-voltage current, and high-voltage battery cell temperature. The battery management system 04 is used to determine the working modes of the low-voltage battery cell module 01 and the high-voltage battery cell module 02 according to the low-voltage battery cell parameters and the high-voltage battery cell parameters.

[0050] In the embodiment of the present application, the low-voltage battery cell module 01 and the high-voltage battery cell module 02 are integrated into the same battery pack. The low-voltage battery cell module directly supplies power to the vehicle low-voltage parts, with relatively high battery efficiency. A bidirectional DCDC converter 03 is provided between the low-voltage battery cell module 01 and the high-voltage battery cell module 02, which can realize the charging of the high-voltage battery cell module 02 by the low-voltage battery cell module 01 and the charging of the low-voltage battery cell module 01 by the high-voltage battery cell module 02. The low-voltage battery cell module 01 and the high-voltage battery cell module 02 can share a set of battery management system 04, which not only reduces costs but also improves safety.

[0051] In one of the embodiments, the battery management system 04 includes:

[0052] The low-voltage slave control unit 41 is electrically connected to the low-voltage battery cell module 01 and is used to collect low-voltage battery cell parameters;

[0053] The high-voltage slave control unit 42 is electrically connected to the high-voltage battery cell module 01 and is used to collect high-voltage battery cell parameters;

[0054] The master control unit 43 is electrically connected to the low-voltage slave control unit 41 and the high-voltage slave control unit 42, and is used to determine the current working mode of the power supply system according to the low-voltage battery cell parameters and the high-voltage battery cell parameters.

[0055] Specifically, on the basis of the existing battery management system 04, a low-voltage slave control unit 41 is newly added, which is used to collect the low-voltage battery cell parameters of the low-voltage battery cell module 01, including low-voltage SOC, low-voltage voltage, low-voltage current, and low-voltage battery cell temperature, etc. The high-voltage slave control unit 42 is electrically connected to the high-voltage battery cell module 01 and is used to collect the high-voltage battery cell parameters of the high-voltage battery cell module 02, including high-voltage SOC, high-voltage voltage, high-voltage current, and high-voltage battery cell temperature. After the low-voltage slave control unit 41 and the high-voltage slave control unit 42 respectively collect the low-voltage battery cell parameters and the high-voltage battery cell parameters, they send the low-voltage battery cell parameters and the high-voltage battery cell parameters to the master control unit 43, and the master control unit 43 analyzes the two parameters to determine the working modes of the low-voltage battery cell module 01 and the high-voltage battery cell module 02.

[0056] In one embodiment, the master control unit 43 includes:

[0057] The low-voltage acquisition module 431 is electrically connected to the low-voltage slave control unit 41 and is used to call the low-voltage battery cell parameters, and the low-voltage battery cell parameters include low-voltage SOC, low-voltage voltage, and low-voltage current;

[0058] The high-voltage acquisition module 432 is electrically connected to the high-voltage slave control unit 42 and is used to call the high-voltage battery cell parameters, and the high-voltage battery cell parameters include high-voltage SOC, high-voltage voltage, and high-voltage current;

[0059] The control algorithm module 433 is electrically connected to the low-voltage acquisition module 431 and the high-voltage acquisition module 432, and is used to determine the low-voltage working state of the low-voltage battery cell module 01 according to the low-voltage SOC, low-voltage voltage, and low-voltage current, and determine the high-voltage working state of the high-voltage battery cell module 02 according to the high-voltage SOC, high-voltage voltage, and high-voltage current.

[0060] Specifically, the low-voltage acquisition module 431 is set in the master control unit 43 to be connected to the low-voltage slave control unit 41, obtain the low-voltage battery cell parameters collected by the low-voltage slave control unit 41 and send them to the control algorithm module 433. The control algorithm module 433 determines the low-voltage working state of the low-voltage battery cell module 01 according to the change amount of the low-voltage SOC, the magnitudes of the low-voltage voltage and the low-voltage current, and the low-voltage working state includes a discharging state, a charging state, and a non-working state.

[0061] Similarly, the high-voltage acquisition module 432 is connected to the high-voltage slave control unit 42, obtains the high-voltage battery cell parameters collected by the high-voltage slave control unit 42, and sends them to the control algorithm module 433. The control algorithm module 433 determines the low-voltage working state of the high-voltage battery cell module 02 based on the change in high-voltage SOC, the magnitudes of the high-voltage voltage and high-voltage current. The low-voltage working state includes a discharging state, a charging state, and a non-working state.

[0062] In one embodiment, the master control unit further includes:

[0063] A communication module 434, electrically connected to the control algorithm module 433, the low-voltage acquisition module 431, and the high-voltage acquisition module 432, for sending the low-voltage battery cell parameters, the high-voltage battery cell parameters, the low-voltage working state, and the high-voltage working state to the vehicle control system.

[0064] Specifically, the communication module 434 can be a vehicle CAN communication, used to implement the communication between the battery management system 04 and the vehicle control system. In the embodiments of the present application, the low-voltage battery cell parameters, the high-voltage battery cell parameters, the low-voltage working state, and the high-voltage working state are sent to the vehicle control system, and the vehicle control system controls the bidirectional DCDC converter 03 to switch the working mode according to the above data.

[0065] In one embodiment, a pressure sensor 11 is installed in the low-voltage battery cell module 01, and the master control unit 43 further includes a low-voltage control module 435 electrically connected to the communication module 434, for collecting the pressure data of the pressure sensor 11.

[0066] Specifically, a pressure sensor 11 is installed in the low-voltage battery cell module 01 to detect the air pressure in the area of the low-voltage battery cell module 01. When the air pressure is greater than the set air pressure threshold, it is determined that a thermal runaway occurs in the low-voltage battery cell module 01, and the communication module 434 sends the thermal runaway information to the vehicle control system for a thermal runaway response. Compared with the existing 12V independent power supply system, the embodiments of the present application can perform a thermal runaway response on the low-voltage battery cells and have higher safety.

[0067] In one embodiment, the low-voltage battery cell parameters further include the low-voltage battery cell temperature, and the high-voltage battery cell parameters further include the high-voltage battery cell temperature;

[0068] The communication module 434 is further used to send the low-voltage battery cell temperature, the high-voltage battery cell temperature, and the pressure data to the thermal management system and the battery safety system.

[0069] In the embodiment of the present application, the low-voltage battery cell module 01 and the high-voltage battery cell module 02 can share a set of cooling systems, including a water-cooled plate, a PTC, and an AC component. The low-voltage slave control unit 41 also collects the low-voltage battery cell temperature, and the high-voltage slave control unit 42 also collects the high-voltage battery cell temperature. The low-voltage battery cell temperature and the high-voltage battery cell temperature are sent to the thermal management system and the battery safety system through the communication module 434 of the battery management system 04 for battery thermal management and battery safety management to ensure the safety of the battery pack.

[0070] According to needs, the above technical solutions can be combined to achieve the best technical effect.

[0071] Vehicle control system:

[0072] The vehicle control system in the embodiment of the present application, such as Figure 2 shown, includes a vehicle control system 20 and the low-voltage power supply system of any one of the foregoing embodiments;

[0073] The vehicle control system 20 is electrically connected to the battery management system 04 and the bidirectional DCDC converter 03, and is used to control the working state of the bidirectional DCDC converter 03 according to the current working mode of the power supply system.

[0074] Specifically, the vehicle control system 20 is electrically connected to the bidirectional DCDC converter 03, and it can control the working state of the bidirectional DCDC converter 03, including forward output, inverter output, and standby. When the bidirectional DCDC converter 03 outputs forward, it converts the high voltage of the high-voltage battery cell module 02 into low voltage to charge the low-voltage battery cell module 01 or supply power to the vehicle low-voltage components 10; when the bidirectional DCDC converter 03 outputs reversely, it converts the low voltage of the low-voltage battery cell module 01 into high voltage to charge the high-voltage battery cell module 01; when the bidirectional DCDC converter 03 is in standby, the bidirectional DCDC converter 03 does not work, and there is no energy flow between the low-voltage battery cell module 01 and the high-voltage battery cell module 02.

[0075] The vehicle control system 20 obtains the working modes of the low-voltage battery cell module 01 and the high-voltage battery cell module 02 determined by the battery management system 04 to control the working state of the bidirectional DCDC converter 03 to achieve different working modes.

[0076] In one embodiment, the current working mode of the power supply system includes the low-voltage working state of the low-voltage battery cell module 01 and the high-voltage working state of the high-voltage battery cell module 02;

[0077] The vehicle control system 20 is specifically used for:

[0078] When both the low-voltage working state and the high-voltage working state are in the discharge state, control the bidirectional DCDC converter 03 to output forward;

[0079] When the low-voltage working state is the discharging state and the high-voltage working state is the non-working state, control the bi-directional DCDC converter 03 to standby;

[0080] When the low-voltage working state is the discharging state and the high-voltage working state is the charging state, control the bi-directional DCDC converter 03 to output in inversion.

[0081] Specifically, when both the low-voltage working state and the high-voltage working state are the discharging states, at this time, the low-voltage battery cell module 01 directly supplies power to the vehicle low-voltage components 10, and its output power cannot meet the power supply requirements of the low-voltage system. Control the bi-directional DCDC converter 03 to output in the forward direction, convert the high voltage of the high-voltage battery cell module 02 into low voltage and then supply power to the vehicle low-voltage components 10 to meet the power supply requirements of the low-voltage system.

[0082] When the low-voltage working state is the discharging state and the high-voltage working state is the non-working state, at this time, the low-voltage battery cell module 01 directly supplies power to the vehicle low-voltage components 10, and its output power can meet the power supply requirements of the low-voltage system, and there is no need for the high-voltage battery cell module 02 to assist in output. Control the bi-directional DCDC converter 03 to standby.

[0083] When the low-voltage working state is the discharging state and the high-voltage working state is the charging state, at this time, the low-voltage battery cell module 01 directly supplies power to the vehicle low-voltage components 10, and its output power has a surplus in addition to the power supply requirements of the low-voltage system. Then control the bi-directional DCDC converter 03 to output in inversion, convert the low voltage of the low-voltage battery cell module 01 into high voltage and then charge the high-voltage battery cell module 02 to improve the efficiency of the electric quantity.

[0084] The embodiment of the present application realizes the electric energy conversion between the low-voltage battery cell module 01 and the high-voltage battery cell module 02 by controlling the working state of the bi-directional DCDC converter 03, so that the electric energy can be reasonably utilized and the efficiency of the power supply system is improved.

[0085] In one of the embodiments, as Figure 2 shown, the vehicle control system further includes a thermal management system 30 and a battery safety system 40. Both the thermal management system 30 and the battery safety system 40 are electrically connected to the battery management system 04 and are used to control battery thermal management and battery safety management according to the low-voltage battery cell parameters and the high-voltage battery cell parameters.

[0086] Specifically, the thermal management system 30 and the battery safety system 40 are electrically connected to the communication module 434 in the battery management system 04, and send the low-voltage cell parameters and high-voltage cell parameters collected by the battery management system 04 to the thermal management system 30 and the battery safety system 40. The low-voltage cell parameters include the low-voltage cell temperature, and the high-voltage cell parameters include the high-voltage cell temperature. The thermal management system 30 and the battery safety system 40 perform thermal management and safety monitoring on the battery pack according to the low-voltage cell temperature and the high-voltage cell temperature, including controlling the water temperature and flow rate of the water-cooling plate to maintain the temperature of the battery pack within a suitable range.

[0087] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0088] The above are only the principles and preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, the implementation manners obtained by appropriately combining the technical solutions separately disclosed in different embodiments are also included in the technical scope of the present invention. Based on the principle of the present application, several other variations can also be made, which should also be regarded as the protection scope of the present application.

Claims

1. A low-voltage power supply system, characterized in that, Comprising: A battery pack having a low-voltage cell module and a high-voltage cell module, wherein the low-voltage cell module is used to directly supply power to the low-voltage components of the whole vehicle; A bidirectional DCDC converter electrically connected to both the low-voltage cell module and the high-voltage cell module, for realizing bidirectional charging and discharging between the low-voltage cell module and the high-voltage cell module; A battery management system electrically connected to both the low-voltage cell module and the high-voltage cell module, for collecting the low-voltage cell parameters of the low-voltage cell module and the high-voltage cell parameters of the high-voltage cell module, and determining the current working mode of the power supply system according to the low-voltage cell parameters and the high-voltage cell parameters.

2. The low-voltage power supply system according to claim 1, characterized in that The battery management system includes: A low-voltage slave control unit electrically connected to the low-voltage cell module, for collecting the low-voltage cell parameters; A high-voltage slave control unit electrically connected to the high-voltage cell module, for collecting the high-voltage cell parameters; A main control unit electrically connected to the low-voltage slave control unit and the high-voltage slave control unit, for determining the current working mode of the power supply system according to the low-voltage cell parameters and the high-voltage cell parameters.

3. The low-voltage power supply system according to claim 2, characterized in that, The main control unit includes: A low-voltage acquisition module electrically connected to the low-voltage slave control unit, for calling the low-voltage cell parameters, and the low-voltage cell parameters include low-voltage SOC, low-voltage voltage and low-voltage current; A high-voltage acquisition module electrically connected to the high-voltage slave control unit, for calling the high-voltage cell parameters, and the high-voltage cell parameters include high-voltage SOC, high-voltage voltage and high-voltage current; A control algorithm module electrically connected to the low-voltage acquisition module and the high-voltage acquisition module, for determining the low-voltage working state of the low-voltage cell module according to the low-voltage SOC, the low-voltage voltage and the low-voltage current, and determining the high-voltage working state of the high-voltage cell module according to the high-voltage SOC, the high-voltage voltage and the high-voltage current.

4. The low-voltage power supply system according to claim 3, characterized in that, The main control unit further includes: A communication module electrically connected to the control algorithm module, the low-voltage acquisition module and the high-voltage acquisition module, for sending the low-voltage cell parameters, the high-voltage cell parameters, the low-voltage working state and the high-voltage working state to the vehicle control system.

5. The low-voltage power supply system according to claim 4, wherein A pressure sensor is installed in the low-voltage cell module, and the main control unit further includes a low-voltage control module electrically connected to the communication module, for collecting the pressure data of the pressure sensor.

6. The low-voltage power supply system according to claim 4, wherein The low-voltage cell parameters further include low-voltage cell temperature, and the high-voltage cell parameters further include high-voltage cell temperature; The communication module is further used for sending the low-voltage cell temperature, the high-voltage cell temperature and the pressure data to the thermal management system and the battery safety system.

7. A vehicle control system, characterized in that, Including a vehicle control system and the low-voltage power supply system according to any one of claims 1-6; The vehicle control system is electrically connected to the battery management system and the bidirectional DCDC converter, for controlling the working state of the bidirectional DCDC converter according to the current working mode of the power supply system.

8. The vehicle control system according to claim 7, wherein The current working mode of the power supply system includes the low-voltage working state of the low-voltage cell module and the high-voltage working state of the high-voltage cell module; The vehicle control system is specifically used for: When both the low-voltage operating state and the high-voltage operating state are discharge states, control the bidirectional DCDC converter to output in the forward direction; When the low-voltage operating state is a discharge state and the high-voltage operating state is an inoperative state, control the bidirectional DCDC converter to standby; When the low-voltage operating state is a discharge state and the high-voltage operating state is a charging state, control the bidirectional DCDC converter to output in the inverse direction.

9. The vehicle control system according to claim 7, wherein It further includes a thermal management system and a battery safety system, both of which are electrically connected to the battery management system and are used to control battery thermal management and battery safety management according to the low-voltage cell parameters and the high-voltage cell parameters.

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