Battery pack, vehicle power supply system and method thereof, and vehicle

Abstract

The invention discloses a battery pack, a vehicle power supply system and method and a vehicle, and belongs to the technical field of vehicle power supply, the battery pack comprises a high-voltage power supply module, the high-voltage power supply module comprises a plurality of first battery cells, and the plurality of first battery cells are connected in series or in parallel; the low-voltage power supply module is connected with the high-voltage power supply module through the direct current conversion module, the low-voltage power supply module comprises a plurality of second battery cells, and the plurality of second battery cells are connected in series; the number of the first battery cells is greater than that of the second battery cells. According to the embodiment of the invention, a part of the battery cells in the vehicle battery pack are separated to be integrated into the low-voltage power supply module, and the remaining part is still integrated into the high-voltage power supply module, so that the power supply requirement of the low-voltage power utilization unit on the vehicle is met under the condition that the size of the battery pack and power driving are not changed; and the space for rearranging and installing the low-voltage battery on the vehicle is reduced, and the internal space of the vehicle is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle power supply technology, and more particularly to a battery pack, a vehicle power supply system and method thereof, and a vehicle. Background Technology

[0002] New energy vehicles typically have two power sources: a low-voltage battery and a high-voltage battery. The low-voltage battery primarily powers the locking and unlocking components when the vehicle is in sleep mode and supports vehicle starting. The high-voltage battery, on the other hand, mainly powers high-voltage components such as the drive motor, air conditioning high-voltage components, and DC-DC converters. However, the low-voltage battery is usually designed separately, requiring additional space in the vehicle. Summary of the Invention

[0003] This application provides a battery pack, a vehicle power supply system and method thereof, and a vehicle, aimed at solving the aforementioned technical problems.

[0004] To achieve the above objectives, in a first aspect, a battery pack is provided, comprising: A high-voltage power supply module, the high-voltage power supply module comprising a plurality of first cells, the plurality of first cells being connected in series or in parallel; A low-voltage power supply module is connected to the high-voltage power supply module via a DC-DC conversion module. The low-voltage power supply module includes multiple second battery cells connected in series with each other. The number of the first battery cells is greater than the number of the second battery cells.

[0005] In conjunction with the first aspect, the high-voltage power supply module includes a first input terminal and a first output terminal, the first input terminal and the first output terminal being used to connect to a high-voltage power distribution module; The low-voltage power supply module includes a second input terminal and a second output terminal, which are used to connect to the low-voltage power distribution module.

[0006] In a second aspect, a vehicle power supply system is provided, comprising a battery pack as described in any one of the first aspects, and: A high-voltage power distribution module, configured to connect a high-voltage power supply module and a motor controller, the motor controller being configured to control a drive motor; A low-voltage power distribution module is configured to connect a low-voltage power supply module and a low-voltage power consumption unit, wherein the low-voltage power supply module supplies power to the low-voltage power consumption unit through the low-voltage power distribution module; A DC-DC converter module is connected to the high-voltage power supply module and the low-voltage power supply module respectively. The DC-DC converter module is configured to convert the high voltage of the high-voltage power supply module into a low voltage input to the low-voltage power supply module. A first control module is connected to the low-voltage power supply module and is configured to control the output current of the low-voltage power supply module. A second control module is connected in parallel with the first control module, and the second control module is configured to control the input current of the low-voltage power supply module.

[0007] In conjunction with the second aspect, the first control module includes a first control switch, which is connected to the second input terminal or the second output terminal of the low-voltage power supply module; The second control module includes a second control switch, which is connected in antiparallel to the first control switch.

[0008] In conjunction with the second aspect, the first control module includes a first control switch and a third control switch, the first control switch being connected to the second input terminal of the low-voltage power supply module, and the third control switch being connected to the second output terminal of the low-voltage power supply module.

[0009] In conjunction with the second aspect, the second control module includes a second control switch and a fourth control switch, wherein the second control switch is connected in antiparallel to the first control switch, and the fourth control switch is connected in antiparallel to the third control switch.

[0010] Thirdly, a vehicle power supply method is provided, applied to a vehicle power supply system as described in any one of the second aspects, the method comprising: Under the condition that the first preset condition is met, a high-voltage power supply module is used to supply power to the electrical unit of the vehicle; Under the condition that the second preset condition is met, a low-voltage power supply module is used to supply power to the power consumption unit; The first preset condition includes the power required by the power-consuming unit being greater than or equal to a preset power, and / or the power of the low-voltage power supply module being lower than a preset power value. The second preset condition includes that the required power of the power-consuming unit is less than the preset power, and / or that the power of the low-voltage power supply module is greater than or equal to the preset power value.

[0011] In conjunction with the third aspect, the method further includes: Based on the power consumption request of the power consumption unit, the first control switch and / or the third control switch are closed to enable the low-voltage power supply module to supply power to the power consumption unit.

[0012] In conjunction with the third aspect, the method further includes: Based on the charging request from the low-voltage power supply module, the second control switch and / or the fourth control switch are closed to allow the high-voltage power supply module to charge the low-voltage power supply module.

[0013] Fourthly, a vehicle is provided, including a battery pack as described in any one of the first aspects, or a vehicle power supply system as described in any one of the second aspects.

[0014] One of the above technical solutions has the following advantages or beneficial effects: This application provides a battery pack, including: a high-voltage power supply module, which includes multiple first cells connected in series or in parallel; and a low-voltage power supply module, which is connected to the high-voltage power supply module via a DC-DC converter module, and includes multiple second cells connected in series; the number of first cells is greater than the number of second cells. This application integrates a portion of the cells in the vehicle battery pack into a low-voltage power supply module, while retaining the remaining portion as a high-voltage power supply module. Without changing the battery pack size or power drive, this not only meets the power supply requirements of the low-voltage electrical units in the vehicle but also reduces the space required for rearranging and installing low-voltage batteries in the vehicle, thus improving the vehicle's interior space. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the module connections of a battery pack according to an exemplary embodiment of this disclosure; Figure 2 This is a schematic diagram of the module connections of a vehicle control system according to an exemplary embodiment of this disclosure; Figure 3 A schematic diagram of a low-voltage power supply module provided in an exemplary first embodiment of this disclosure; Figure 4 A schematic diagram of a low-voltage power supply module provided in an exemplary second embodiment of this disclosure; Figure 5 A schematic diagram of a low-voltage power supply module provided in an exemplary third embodiment of this disclosure; Figure 6 A schematic diagram of a low-voltage power supply module provided in the exemplary fourth embodiment of this disclosure; Figure 7 This is a schematic flowchart of a vehicle control method according to an exemplary embodiment of the present disclosure.

[0017] Explanation of icon numbers: 100 - Battery pack; 110 - High voltage power supply module; 111 - First battery cell; 112 - First input terminal; 113 - First output terminal; 120 - Low voltage power supply module; 121 - Second battery cell; 122 - Second input terminal; 123 - Second output terminal. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] Furthermore, descriptions involving "first," "second," etc., in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0020] Those skilled in the art who applied for this application noted that the 12V battery in the vehicle is only used when the vehicle is locked and powered off, and when the vehicle is started, making its usage scenario relatively limited. Furthermore, the battery's energy comes from the power battery. The battery requires additional space within the vehicle, occupying a significant amount of space and incurring additional costs.

[0021] like Figure 1As shown in the illustration, this application proposes a battery pack 100, comprising: a high-voltage power supply module 110, which includes multiple first cells 111 connected in series or parallel; and a low-voltage power supply module 120, which is connected to the high-voltage power supply module 110 via a DC-DC converter module, and includes multiple second cells 121 connected in series. The number of first cells 111 is greater than the number of second cells 121. Specifically, the high-voltage power supply module 110 is constructed by connecting multiple first cells 111 in series or parallel to form a cell string, and then connecting them in series again. The voltage of a single first cell 111 is approximately 3 to 4V. By using the above method, the voltage of all first cells 111 can be accumulated, resulting in a higher output voltage. The low-voltage power supply module 120 is constructed by connecting multiple second cells 121 in series. By connecting a small number of second cells 121 in series, the output voltage is controlled within a lower range, thereby enabling power supply to low-voltage power consumption units.

[0022] It is worth noting that the first cell 111 and the second cell 121 are cells with the same structure, differing only in name. That is, this application divides the original cells in the battery pack 100 into multiple cells to form a low-voltage power supply module 120 for use by low-voltage electrical units in the vehicle, thereby reducing space requirements in the vehicle. Typically, the rated voltage of low-voltage electrical units in a vehicle is 12V. Therefore, only four cells from the battery pack 100 are needed to form a low-voltage power supply module 120 with a voltage of 12V to 16V, which can meet the needs of all low-voltage electrical units in the vehicle. Furthermore, it should be noted that the embodiment of this application using four cells to form a low-voltage power supply module 120 is merely an example. In some usage scenarios, five, six, or more cells can be used to form a higher voltage low-voltage power supply module 120 to meet different usage scenarios. This embodiment will not be listed here.

[0023] It is understood that, in this embodiment of the application, by separating a portion of the original battery cells in the vehicle battery pack 100 and integrating them into a low-voltage power supply module 120, while still integrating the remaining portion into a high-voltage power supply module 110, the power supply requirements of the low-voltage electrical units on the vehicle are met without changing the size of the battery pack 100 and the power drive, and the interior space of the vehicle is increased.

[0024] like Figure 1As shown in this embodiment, the high-voltage power supply module 110 includes a first input terminal 112 and a first output terminal 113, which are used to connect to the high-voltage power distribution module. Specifically, the first input terminal 112 and the first output terminal 113 of the high-voltage power supply module 110 are the negative and positive terminals, respectively. The high-voltage power supply module 110 is mainly used in high-voltage scenarios. When the battery pack 100 is used in a vehicle, the high-voltage power supply module 110 first delivers high-voltage DC power to the high-voltage distribution box through the positive terminal. After being regulated by the high-voltage distribution box, the current is delivered to the motor controller. The power module in the motor controller inverts the high-voltage DC power into three-phase AC power. After the three-phase AC power is input into the drive motor, the stator coil of the drive motor generates a rotating magnetic field. The stator magnetic field attracts and repels the permanent magnets on the rotor, thereby driving the rotor to rotate at high speed, realizing the driving of the vehicle.

[0025] It is understandable that when the battery pack 100 is used in a vehicle, the high-voltage power supply module 110 obtained by integrating multiple first cells 111 can drive the vehicle through the high-voltage distribution box, motor controller and drive motor, thereby driving the vehicle.

[0026] like Figure 1 As shown in this embodiment, the low-voltage power supply module 120 includes a second input terminal 122 and a second output terminal 123, which are used to connect to a low-voltage power distribution module. Specifically, the second input terminal 122 and the second output terminal 123 of the low-voltage power supply module 120 are the negative and positive terminals, respectively. The low-voltage power supply module 120 is mainly used in low-voltage scenarios. The low-voltage power supply module 120 outputs low-voltage DC power through its positive terminal and directly connects to the low-voltage power distribution box. The low-voltage power distribution box supplies power to low-voltage devices, such as anti-theft systems, remote key receiver modules, and dashcams, through corresponding circuits.

[0027] It is understandable that when the battery pack 100 is used in a vehicle, the low-voltage power supply module 120 obtained by integrating multiple second cells 121 can supply power to the low-voltage electrical units in the vehicle through the current configuration of the low-voltage distribution box, thereby meeting the normal use of the low-voltage electrical units in the vehicle.

[0028] In summary, this embodiment of the application integrates a portion of the original battery cells in the vehicle battery pack 100 into a low-voltage power supply module 120, while still integrating the remaining portion into a high-voltage power supply module 110. Without changing the size of the battery pack 100 and the power drive, it not only meets the power supply requirements of the low-voltage electrical units in the vehicle, but also reduces the space required to rearrange and install the low-voltage battery in the vehicle, thereby improving the interior space of the vehicle.

[0029] like Figure 1 and Figure 2As shown in the embodiments of this application, a vehicle power supply system is also provided, including a battery pack as provided in any of the above embodiments, and: a high-voltage power distribution module configured to connect a high-voltage power supply module and a motor controller, the motor controller being configured to control a drive motor; a low-voltage power distribution module configured to connect a low-voltage power supply module and a low-voltage power consumption unit, the low-voltage power supply module supplying power to the low-voltage power consumption unit through the low-voltage power distribution module; a DC-DC conversion module connected to both the high-voltage power supply module and the low-voltage power supply module, the DC-DC conversion module being configured to convert the high voltage of the high-voltage power supply module into a low voltage input to the low-voltage power supply module; a first control module connected to the low-voltage power supply module, the first control module being configured to control the output current of the low-voltage power supply module; and a second control module connected in parallel with the first control module, the second control module being configured to control the input current of the low-voltage power supply module. Specifically, the high-voltage power distribution module is the high-voltage distribution box. This box precisely distributes the high-voltage DC power output from the high-voltage power supply module to high-voltage electrical components within the vehicle, such as the motor controller, drive motor, on-board charger, air conditioning compressor, heater, and DC-DC converter, through internal copper busbars and branch circuits. Furthermore, the high-voltage distribution box also provides safety protection. It contains built-in high-voltage relays, fuses, and a pre-charging circuit, forming a safety barrier for the high-voltage system. The relays control the on / off state of the high-voltage circuit (closing when the vehicle starts and opening during a fault), controlling the power supply and de-energization of the high-voltage system. The fuses quickly melt and disconnect faulty branches in case of short circuits or overloads, preventing damage to the high-voltage power supply module and components, and thus preventing fires. The pre-charging circuit slowly charges the high-voltage capacitors through a pre-charging resistor when the vehicle is powered on, preventing damage or arcing caused by sudden high-current surges.

[0030] The low-voltage power distribution module, also known as the low-voltage distribution box, receives the low-voltage DC power (typically 12V) from the low-voltage power supply module and distributes it through internal fuses and relays to low-voltage electrical units within the vehicle, such as the body control module, sensors, headlights, central control screen, air conditioning blower, windshield wipers, window regulators, audio system, anti-theft system, airbag controller, and dashcam. The low-voltage distribution box also contains miniature fuses and relays to ensure the safety of the low-voltage system. The miniature fuses blow in case of short circuits (such as in the headlight wiring) or overloads, protecting the low-voltage electrical units and wiring, and preventing the entire vehicle's low-voltage system from failing. The relays allow for small-current control of large-current applications; for example, the ignition switch signal can control a relay to connect the power supply circuit for high-power devices like the air conditioning and windshield wipers, reducing the load on the control circuitry.

[0031] In this embodiment, the DC-DC converter module includes a DC-DC (Direct Current to Direct Current Converter) converter. The main function of the DC-DC converter module is to convert the high-voltage DC power from the high-voltage power supply module into a stable low-voltage DC power to charge the low-voltage battery. Simultaneously, the converted low-voltage power directly supplies all low-voltage components in the vehicle, preventing the low-voltage battery from running out of power when powered alone. Furthermore, the DC-DC converter module can dominate the low-voltage power supply while the vehicle is running, and cease operation when the engine is off or the high-voltage power supply module is not activated, switching to independent power supply for the low-voltage battery to ensure a stable connection of the low-voltage system.

[0032] In this embodiment, the low-voltage power supply module has a discharge mode and a charging mode. In discharge mode, the low-voltage power supply module can supply power to the low-voltage electrical units inside the vehicle; while in charging mode, when the battery level drops to a certain level, the low-voltage power supply module needs to be charged. The current flow direction is diametrically opposed for the low-voltage power supply module in these two modes. Therefore, to avoid confusion between the two power supply modes, a first control module controls the on / off state of the discharge circuit of the low-voltage power supply module, and a second control module controls the on / off state of the charging circuit in the low-voltage power supply mode. That is, when the low-voltage power supply module is in discharge mode, the first control module is turned on and the second control module is turned off; while when the low-voltage power supply module is in charging mode, the second control module is turned on and the first control module is turned off, thereby enabling the independent operation of the two modes.

[0033] It is worth noting that the low-voltage power supply module is also connected to the BMS (Battery Management System) to collect the voltage, current, and temperature of the low-voltage power supply module in real time, and calculate the remaining power and health status based on the voltage, current, and temperature, and feed it back to the vehicle's infotainment system. In addition, the BMS can also detect abnormalities such as overvoltage, undervoltage, overcurrent, and overheating of the low-voltage power supply module, thereby immediately cutting off the high-voltage circuit to prevent damage or fire to the low-voltage power supply module. At the same time, the BMS can also control the charging current and voltage of the low-voltage power supply module to prevent overcharging, and automatically stop charging after it is completed.

[0034] It is understandable that by applying the battery pack in the above embodiments to the vehicle power supply system, the power supply requirements of the low-voltage electrical units on the vehicle are met without changing the size of the battery pack and the power drive, and the space required to rearrange and install the low-voltage battery on the vehicle is reduced, thereby improving the interior space of the vehicle.

[0035] like Figure 2 and Figure 3As shown in the embodiment of this application, the first control module includes a first control switch, which is connected to the second input terminal or the second output terminal of the low-voltage power supply module. Specifically, the first control switch is connected to the positive or negative terminal of the low-voltage power supply module. When the low-voltage power supply module needs to supply power to the low-voltage power consumption unit, it can control the first control switch to close; when the low-voltage power supply module needs to charge, it can control the first control switch to open. It is worth noting that the first control switch has a unidirectional conduction characteristic, that is, when the first control switch is connected to the positive terminal of the low-voltage power supply module, the first control switch only allows current output; while when the first control switch is connected to the negative terminal of the low-voltage power supply module, the first control switch only allows current input.

[0036] It is understandable that by connecting the first control switch to the positive or negative terminal of the low-voltage power supply module, the on / off state of the discharge circuit of the low-voltage power supply module is controlled, thereby avoiding interference between the charging circuit and the discharge circuit, which could damage the low-voltage power supply module or the low-voltage power consumption unit.

[0037] like Figure 2 and Figure 4 As shown in the embodiment of this application, the second control module includes a second control switch, which is connected in antiparallel to the first control switch. Specifically, the second control switch and the first control switch are connected in antiparallel, meaning that regardless of whether the first control switch is connected to the positive or negative terminal of the low-voltage power supply module, the second control switch is always connected in antiparallel to the first control switch. The second control switch also has a unidirectional conduction characteristic. When the low-voltage power supply module needs to be charged, the first control switch is opened and the second control switch is turned on, allowing the charging current to flow into the low-voltage power supply module through the second control switch, thus charging the low-voltage power supply module. When the low-voltage power supply module needs to supply power to the low-voltage power consumption unit, the second control switch is opened and the first control switch is turned on, allowing the discharging current to flow to the low-voltage power consumption unit through the first control switch, thus discharging the low-voltage power supply module.

[0038] It is understandable that by connecting the first and second control switches in anti-parallel configuration to the positive or negative terminals of the low-voltage power supply module, precise control over the on / off state of the charging and discharging circuits of the low-voltage power supply module is achieved, thereby preventing interference between the charging and discharging circuits and avoiding damage to the low-voltage power supply module or the low-voltage power consumption unit.

[0039] like Figure 2 and Figure 5As shown in this embodiment, the first control module includes a first control switch and a third control switch. The first control switch is connected to the second input terminal of the low-voltage power supply module, and the third control switch is connected to the second output terminal of the low-voltage power supply module. Specifically, control switches can be set at both the positive and negative terminals of the low-voltage power supply module to achieve dual-terminal control in the discharge mode of the low-voltage power supply module. That is, the first control switch is set at the negative terminal of the low-voltage power supply module, and the third control switch is set at the positive terminal. Both the first and third control switches have unidirectional conduction characteristics, that is, the first control switch only allows current input, and the third control switch only allows current output. When the low-voltage power supply module needs to discharge to the low-voltage power consumption unit, the first and third control switches can be closed simultaneously to connect the discharge circuit; when the low-voltage power supply module needs to charge, the first and third control switches are opened simultaneously to disconnect the discharge circuit.

[0040] It is understandable that by setting a third control switch and a first control switch on the positive and negative terminals of the low-voltage power supply module respectively, the dual-terminal on / off control of the discharge circuit of the low-voltage power supply module is achieved, thereby avoiding mutual interference between the charging circuit and the discharge circuit, which could cause damage to the low-voltage power supply module or the low-voltage power consumption unit.

[0041] like Figure 2 and Figure 6 As shown in this embodiment, the second control module includes a second control switch and a fourth control switch. The second control switch is connected in parallel with the first control switch, and the fourth control switch is connected in antiparallel with the third control switch. Specifically, when the first control switch is set at the negative terminal of the low-voltage power supply module and the third control switch is set at the positive terminal, the second and fourth control switches can also be set at both the positive and negative terminals of the low-voltage power supply module to achieve dual-end control in the charging mode of the low-voltage power supply module. That is, the second control switch is connected in antiparallel with the first control switch, and the fourth control switch is connected in antiparallel with the third control switch. Both the second and fourth control switches have unidirectional conduction characteristics, meaning the second control switch only allows current output, and the fourth control switch only allows current input. When the low-voltage power supply module needs to discharge to the low-voltage power consumption unit, the second and fourth control switches can be disconnected simultaneously to disconnect the charging circuit; when the low-voltage power supply module needs to charge, the second and fourth control switches are disconnected simultaneously to connect the charging circuit.

[0042] It should be noted that the first, second, third, and fourth control switches all include any one or more combinations of MOS (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), and transistors. The specific transistor used as the first, second, third, or fourth control switch can be selected according to the actual situation; this application does not provide examples of such switches.

[0043] It is understandable that by connecting the fourth and second control switches in antiparallel to the third and first control switches of the low-voltage power supply module, the dual-end switching of the charging circuit of the low-voltage power supply module is controlled, thereby avoiding mutual interference between the charging and discharging circuits and preventing damage to the low-voltage power supply module or the low-voltage power consumption unit.

[0044] In summary, the vehicle power supply system provided in this application uses the battery pack mentioned in the above embodiments for power supply. By setting up a first control module and a second control module, the charging circuit and discharging circuit of the low-voltage power supply module are controlled, avoiding interference between the low-voltage power supply module in the two modes, improving the reliability of the low-voltage power supply module. Furthermore, without changing the battery pack size and power drive, this battery pack not only meets the power supply requirements of the low-voltage electrical units in the vehicle, but also reduces the space required to rearrange and install the low-voltage battery in the vehicle, thereby improving the interior space of the vehicle.

[0045] like Figure 7 As shown, this application also provides a vehicle power supply method for controlling a vehicle power supply system as provided in any of the above embodiments, the method comprising: S1: Under the condition that the first preset condition is met, the high-voltage power supply module is used to supply power to the vehicle's electrical unit. The first preset condition includes that the power required by the electrical unit is greater than or equal to the preset power, and / or that the power of the low-voltage power supply module is lower than the preset power value.

[0046] The specific method includes: the power consumption unit includes a low-voltage power consumption unit with a preset power of 1kW. That is, when there are many low-voltage power consumption units and their required power is greater than or equal to 1kW, in order to avoid excessive losses of the low-voltage power supply module, the high-voltage power supply module is switched to the power supply unit, and the output voltage is increased through the DC-DC conversion module. Thus, the low-voltage power consumption is supplied through the high-efficiency range of the DC-DC conversion module, which meets the high load requirements of the low-voltage power consumption unit.

[0047] When the low-voltage power supply module's power is below the preset power value, a high-voltage power supply module can also be used to supply power. The preset power value is 20% SOC (State of Charge). That is, when the low-voltage power supply module's power is below 20% SOC, in order to avoid the low-voltage power supply module being unable to meet the continuous output and causing the low-voltage power unit to be unable to work at the rated power, a high-voltage power supply module is used to provide a stable current to the low-voltage power unit.

[0048] For example, in some scenarios, the embodiments of this application use cells of the same capacity as the high-voltage power supply module, allowing the low-voltage power supply module to independently power the vehicle's sentry mode for 24 hours. When sentry mode is activated, all controllers unrelated to the sentry mode can be put into sleep mode, thereby reducing energy consumption. Traditional 12V batteries have low capacity and cannot meet power supply requirements, necessitating high voltage from the vehicle via a DC-DC converter to power the sentry mode function. The solution provided in this application embodiment consumes only 1kWh in 24 hours, a reduction of 3.8kWh compared to traditional batteries. Traditional batteries typically have a capacity of around 20AH, with an energy of 252.8Wh. However, for battery protection, the discharge depth is generally around 40%, leaving only 101.12Wh of usable energy. Since a single sentry mode function typically consumes 42W, a recharge request is required after only 2.4 hours of power supply from a 12V battery, severely impacting battery life. The usual practice is to activate the DC-DC converter to power sentry mode, but activating the high voltage generates additional power, approximately 158W. The battery cells used in this application are from a high-voltage power supply module. The battery cell capacity of a high-voltage power supply module is generally above 100AH, and the usable energy is generally above 1kWh, which can fully meet the power supply requirements of the sentry mode independently.

[0049] S2: Under the condition that the second preset condition is met, the low-voltage power supply module is used to supply power to the power consumption unit; wherein, the second preset condition includes that the power required by the power consumption unit is less than the preset power, and / or that the power of the low-voltage power supply module is greater than or equal to the preset power value.

[0050] Specific methods include: when the power supply of the low-voltage power unit is less than 1kW, and / or when the power of the low-voltage power supply module is greater than or equal to 20% SOC, the low-voltage power supply module can be used to supply power to the low-voltage power unit, thereby improving the efficiency of DC power usage.

[0051] In this embodiment, the method further includes: controlling the first control switch and / or the third control switch to close based on the power consumption request of the power consumption unit, so that the low-voltage power supply module supplies power to the power consumption unit. Specifically, control switches can be set at both the positive and negative terminals of the low-voltage power supply module to realize the discharge circuit control of the low-voltage power supply module. For example, if a first control switch is set at the positive or negative terminal of the low-voltage power supply module, the first control switch can be controlled to close when the low-voltage power supply module needs to supply power to the low-voltage power consumption unit, and the first control switch can be controlled to open when the low-voltage power supply module needs to be charged. It is worth noting that the first control switch has a unidirectional conduction characteristic, that is, when the first control switch is connected to the positive terminal of the low-voltage power supply module, the first control switch only allows current output; and when the first control switch is connected to the negative terminal of the low-voltage power supply module, the first control switch only allows current input. At the same time, a first control switch can also be set at the negative terminal of the low-voltage power supply module, and a third control switch can be set at the positive terminal, and both the first control switch and the third control switch have a unidirectional conduction characteristic, that is, the first control switch only allows current input, and the third control switch only allows current output. When the low-voltage power supply module needs to discharge to the low-voltage power consumption unit, the first control switch and the third control switch can be closed simultaneously to connect the discharge circuit; when the low-voltage power supply module needs to charge, the first control switch and the third control switch can be opened simultaneously to disconnect the discharge circuit.

[0052] It is understandable that by setting control switches on the positive and negative terminals of the low-voltage power supply module, the discharge circuit of the low-voltage power supply module is controlled to prevent the charging and discharging circuits from interfering with each other and causing damage to the low-voltage power supply module or the low-voltage power consumption unit.

[0053] In this embodiment, the method further includes: based on a charging request from the low-voltage power supply module, controlling the second control switch and / or the fourth control switch to close, so that the high-voltage power supply module charges the low-voltage power supply module. Specifically, the positive and negative terminals of the low-voltage power supply module can also be provided with a second control switch and a fourth control switch connected in anti-parallel to the first control switch and the third control switch, thereby realizing the control of the charging circuit of the low-voltage power supply module. When the first control switch is provided at the positive or negative terminal of the low-voltage power supply module, the second control switch is connected in anti-parallel to the first control switch. The second control switch also has a unidirectional conduction characteristic. When the low-voltage power supply module needs to be charged, the first control switch is opened and the second control switch is turned on, so that the charging current can flow into the low-voltage power supply module through the second control switch to realize the charging of the low-voltage power supply module; when the low-voltage power supply module needs to supply power to the low-voltage power consumption unit, the second control switch is opened and the first control switch is turned on, so that the discharge current can flow to the low-voltage power consumption unit through the first control switch to realize the discharge of the low-voltage power supply module.

[0054] When the negative terminal of the low-voltage power supply module is equipped with the first control switch and the positive terminal with the third control switch, a second control switch can be connected in anti-parallel to the first control switch, and a fourth control switch can be connected in anti-parallel to the third control switch. Both the second and fourth control switches have unidirectional conduction characteristics; that is, the second control switch only allows current output, and the fourth control switch only allows current input. When the low-voltage power supply module needs to discharge to the low-voltage power consumption unit, both the second and fourth control switches can be simultaneously disconnected, thereby disconnecting the charging circuit. Conversely, when the low-voltage power supply module needs to charge, both the second and fourth control switches are simultaneously disconnected, thereby connecting the charging circuit.

[0055] It is understandable that by connecting the fourth and second control switches in antiparallel to the third and first control switches of the low-voltage power supply module, the dual-end switching of the charging circuit of the low-voltage power supply module is controlled, thereby avoiding mutual interference between the charging and discharging circuits and preventing damage to the low-voltage power supply module or the low-voltage power consumption unit.

[0056] In summary, the vehicle power supply method provided in this application, based on the vehicle power supply system and battery pack of the above embodiments, realizes the on / off control of the charging and discharging circuits of the low-voltage power supply module through the first control module and the second control module, avoiding interference between the low-voltage power supply module in the two modes, improving the reliability of the low-voltage power supply module, and the battery pack, without changing the battery pack size and power drive, not only meets the power supply requirements of the low-voltage electrical units on the vehicle, but also reduces the space required to rearrange and install the low-voltage battery on the vehicle, thus improving the interior space of the vehicle.

[0057] This application also provides a vehicle, including a battery pack as provided in any of the above embodiments, or a vehicle power supply system as provided in any of the above embodiments. The working process and beneficial effects of the battery pack or vehicle power supply system have been described in detail in the above embodiments, and will not be repeated here.

[0058] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A battery pack, characterized in that, include: A high-voltage power supply module, the high-voltage power supply module comprising a plurality of first cells, the plurality of first cells being connected in series or in parallel; A low-voltage power supply module is connected to the high-voltage power supply module via a DC-DC conversion module. The low-voltage power supply module includes multiple second battery cells connected in series with each other. The number of the first battery cells is greater than the number of the second battery cells.

2. The battery pack according to claim 1, characterized in that, The high-voltage power supply module includes a first input terminal and a first output terminal, which are used to connect to the high-voltage power distribution module. The low-voltage power supply module includes a second input terminal and a second output terminal, which are used to connect to the low-voltage power distribution module.

3. A vehicle power supply system, characterized in that, The battery pack includes the battery pack as described in any one of claims 1 and 2, and: A high-voltage power distribution module, configured to connect a high-voltage power supply module and a motor controller, the motor controller being configured to control a drive motor; A low-voltage power distribution module is configured to connect a low-voltage power supply module and a low-voltage power consumption unit, wherein the low-voltage power supply module supplies power to the low-voltage power consumption unit through the low-voltage power distribution module; A DC-DC converter module is connected to the high-voltage power supply module and the low-voltage power supply module respectively. The DC-DC converter module is configured to convert the high voltage of the high-voltage power supply module into a low voltage input to the low-voltage power supply module. A first control module is connected to the low-voltage power supply module and is configured to control the output current of the low-voltage power supply module. A second control module is connected in parallel with the first control module, and the second control module is configured to control the input current of the low-voltage power supply module.

4. The vehicle power supply system according to claim 3, characterized in that, The first control module includes a first control switch, which is connected to the second input terminal or the second output terminal of the low-voltage power supply module. The second control module includes a second control switch, which is connected in antiparallel to the first control switch.

5. The vehicle power supply system according to claim 3, characterized in that, The first control module includes a first control switch and a third control switch. The first control switch is connected to the second input terminal of the low-voltage power supply module, and the third control switch is connected to the second output terminal of the low-voltage power supply module.

6. The vehicle power supply system according to claim 5, characterized in that, The second control module includes a second control switch and a fourth control switch. The second control switch is connected in antiparallel to the first control switch, and the fourth control switch is connected in antiparallel to the third control switch.

7. A method for supplying power to a vehicle, characterized in that, Applied to a vehicle power supply system as described in any one of claims 3 to 6, the method comprises: Under the condition that the first preset condition is met, a high-voltage power supply module is used to supply power to the electrical unit of the vehicle; Under the condition that the second preset condition is met, a low-voltage power supply module is used to supply power to the power consumption unit; The first preset condition includes the power required by the power-consuming unit being greater than or equal to a preset power, and / or the power of the low-voltage power supply module being lower than a preset power value. The second preset condition includes that the required power of the power-consuming unit is less than the preset power, and / or that the power of the low-voltage power supply module is greater than or equal to the preset power value.

8. The vehicle power supply method according to claim 7, characterized in that, The method further includes: Based on the power consumption request of the power consumption unit, the first control switch and / or the third control switch are closed to enable the low-voltage power supply module to supply power to the power consumption unit.

9. The vehicle power supply method according to claim 7, characterized in that, The method further includes: Based on the charging request from the low-voltage power supply module, the second control switch and / or the fourth control switch are closed to allow the high-voltage power supply module to charge the low-voltage power supply module.

10. A vehicle, characterized in that, Includes the battery pack as described in any one of claims 1 and 2, or the vehicle power supply system as described in any one of claims 3 to 6.

Images