Power supply device, power supply method, and vehicle

Abstract

The application discloses a power supply device, a power supply method and a vehicle, and relates to the field of power supply. The power supply device comprises a power battery, a voltage reduction module, a control module, a first storage battery, a second storage battery, a first switch unit and a second switch unit. The power battery is connected with the input end of the voltage reduction module. The control end of the first switch unit is connected with the first output end of the control module. The control end of the second switch unit is connected with the second output end of the control module. The control module is used for controlling the first switch unit and the second switch unit to be turned on at different times, and the first switch unit and the second switch unit are not turned on at the same time. In the case that the control module controls the first switch unit to be turned on, the voltage reduction module, the first storage battery and the second storage battery are connected in sequence. In the case that the control module controls the second switch unit to be turned on, the voltage reduction module, the second storage battery and the first storage battery are connected in sequence. The application solves the problem that the cost of low-voltage power supply is high.

Description

Technical Field

[0001] This application relates to the field of power supply technology, and in particular to power supply devices, power supply methods, and vehicles. Background Technology

[0002] In range-extended electric vehicles (REEVs), the high-voltage electricity output from the battery can be stepped down to 24V via a DC / DC converter, thus powering the vehicle's 24V electrical appliances. However, since REEVs are equipped with an engine, some components (such as the engine aftertreatment oxygen sensor and fuel pump) are designed for 12V operation. Currently, a two-stage step-down power supply architecture is commonly used. The first stage uses a DC / DC converter to convert the high-voltage battery electricity to 24V, and the second stage uses a DC / DC converter to step it down to 12V, which, together with a separate 12V battery, powers the 12V electrical appliances. However, this power supply architecture is complex and requires many components, resulting in higher costs for low-voltage power supply.

[0003] The above content is only used to help understand the technical solutions of the embodiments of this application, and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The main objective of this application is to provide a power supply device, power supply method, and vehicle, aiming to solve the technical problem of high cost of low-voltage power supply.

[0005] To achieve the above objectives, embodiments of this application provide a power supply device, which includes a power battery, a step-down module, a control module, a first storage battery, a second storage battery, a first switching unit, and a second switching unit. The power battery is connected to the input terminal of the step-down module, the control terminal of the first switching unit is connected to the first output terminal of the control module, and the control terminal of the second switching unit is connected to the second output terminal of the control module. The control module is used to control the first switching unit and the second switching unit to conduct in a time-sharing manner, and the first switching unit and the second switching unit are not to conduct at the same time; When the control module controls the first switching unit to be turned on, the step-down module, the first battery and the second battery are connected in sequence. When the control module controls the second switching unit to be turned on, the step-down module, the second battery and the first battery are connected in sequence. The output of the step-down module supports connection to a first low-voltage load, and supports connection to a second low-voltage load between the first battery and the second battery.

[0006] In one embodiment, the first switching unit includes a first relay, a second relay, a third relay, and a fourth relay; The control terminals of the first relay, the second relay, the third relay, and the fourth relay are all connected to the first output terminal of the control module. The first terminal of the first relay is connected to the output terminal of the step-down module, and the second terminal of the first relay is connected to the positive terminal of the first battery. The first terminal of the second relay is connected to the negative terminal of the first battery, and the second terminal of the second relay is connected to the positive terminal of the second battery. The first terminal of the third relay is connected to the negative terminal of the second battery, and the second terminal of the third relay is grounded. The first terminal of the fourth relay is connected to the positive terminal of the second battery, and the second terminal of the fourth relay supports connection to the second low-voltage load.

[0007] In one embodiment, the second switching unit includes a fifth relay, a sixth relay, a seventh relay, and an eighth relay; The control terminals of the fifth, sixth, seventh, and eighth relays are all connected to the second output terminal of the control module. The first terminal of the fifth relay is connected to the output terminal of the step-down module, and the second terminal of the fifth relay is connected to the positive terminal of the second battery. The first terminal of the sixth relay is connected to the positive terminal of the first battery, and the second terminal of the sixth relay is connected to the negative terminal of the second battery. The first terminal of the seventh relay is connected to the negative terminal of the first battery, and the second terminal of the seventh relay is grounded. The first terminal of the eighth relay is connected to the negative terminal of the second battery, and the second terminal of the eighth relay supports connection to the second low-voltage load.

[0008] In one embodiment, the control module includes a voltage detection unit, a control unit, and a switch drive unit; The first detection terminal of the voltage detection unit is connected to the positive terminal of the first battery, the second detection terminal of the voltage detection unit is connected to the negative terminal of the first battery, the third detection terminal of the voltage detection unit is connected to the positive terminal of the second battery, and the fourth detection terminal of the voltage detection unit is connected to the negative terminal of the second battery. The output of the voltage detection unit is connected to the input of the control unit; The output terminal of the control unit is connected to the input terminal of the switch drive unit. The first drive terminal of the switch drive unit is used as the first output terminal of the control module, and the second drive terminal of the switch drive unit is used as the second output terminal of the control module.

[0009] In one embodiment, the control unit is further configured to control the switch drive unit to periodically turn off the first switch unit and the second switch unit; When the first and second switching units are turned off, the control unit controls the voltage detection unit to detect the first voltage of the first battery and the second voltage of the second battery.

[0010] In one embodiment, the control unit is further configured to control the switch driving unit to turn off the first switch unit and drive the second switch unit to turn on when the difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference threshold. The control unit is also used to control the switch drive unit to drive the first switch unit to conduct and turn off the second switch unit when the difference between the second voltage and the first voltage is greater than or equal to a preset differential voltage threshold.

[0011] Furthermore, to achieve the above objectives, embodiments of this application also provide a power supply method applied to the power supply device described above. The power supply method includes: The first and second switching units in the power supply device are turned on in a time-sharing manner, so that when the first switching unit is turned on and the second switching unit is turned off, the second low-voltage load is powered through the second storage battery in the power supply device, and when the second switching unit is turned on and the first switching unit is turned off, the second low-voltage load is powered through the first storage battery in the power supply device.

[0012] In one embodiment, the step of controlling the first switching unit and the second switching unit in the power supply device to be turned on in a time-division manner includes: Either the first switching unit or the second switching unit is determined as the target conducting unit, and a target cutting-off unit is determined in the first switching unit and the second switching unit. The target conducting unit and the target cutting-off unit are different. The target conduction unit is turned on, and the target cutoff unit is turned off; After the target conduction unit has been turned on for a preset power supply duration, the target conduction unit is turned off, and the first voltage of the first battery and the second voltage of the second battery are detected. Based on the first voltage and the second voltage, the target turn-on unit and the target turn-off unit are redefined in the first switch unit and the second switch unit, and the steps of controlling the target turn-on unit to turn on and controlling the target turn-off unit to turn off are returned.

[0013] In one embodiment, the step of re-determining the target on-state unit and the target off-state unit in the first switching unit and the second switching unit based on the first voltage and the second voltage includes: If the difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference threshold, the second switching unit is determined to be the target conducting unit and the first switching unit is determined to be the target cutting-off unit. If the difference between the first voltage and the second voltage is less than a preset voltage difference threshold, the first switching unit is determined to be the target conducting unit and the second switching unit is determined to be the target cutting-off unit. When the difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference threshold, the first switching unit is determined to be the target conduction unit and the second switching unit is determined to be the target cut-off unit. If the difference between the second voltage and the first voltage is less than a preset voltage difference threshold, the second switching unit is determined to be the target turn-on unit and the first switching unit is determined to be the target turn-off unit.

[0014] In addition, to achieve the above objectives, this application also provides a vehicle, which includes the power supply device described above and is further used to implement the power supply method described above.

[0015] In addition, to achieve the above objectives, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the power supply method as described above.

[0016] One or more technical solutions proposed in the embodiments of this application have at least the following technical effects: In the power supply device of this application, the power battery is connected to the input terminal of the step-down module. The control module controls the first switching unit and the second switching unit to conduct in a time-sharing manner, but not simultaneously. When the first switching unit is on, the step-down module, the first battery, and the second battery are connected sequentially. When the second switching unit is on, the step-down module, the second battery, and the first battery are connected sequentially. Furthermore, the output terminal of the step-down module supports connection to a first low-voltage load, and the connection between the first battery and the second battery supports connection to a second low-voltage load. Thus, this application only requires one step-down module to convert the high-voltage power from the power battery to low voltage, and the step-down module can supply power to the first low-voltage load. Simultaneously, it can supply power to the second low-voltage load between the two batteries. Compared with the two-stage buck power supply architecture, it reduces the number of buck modules, simplifies the power supply structure, and thus reduces structural costs. Furthermore, since the first and second switching units are time-divisionally turned on, the first and second batteries are alternately connected in series, allowing the two batteries to take turns supplying power to the second low-voltage load. This balances the charging and discharging levels of the two batteries, avoiding excessive wear caused by a single battery supplying power to the second low-voltage load for a long time. This extends the battery's lifespan and reduces the increased costs caused by frequent replacements due to shortened battery life. In summary, this application can solve the technical problem of excessively high low-voltage power supply costs. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of the embodiments of this application.

[0018] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a connection diagram of a high-voltage power battery, a first-stage step-down DC-DC module, a high-voltage main and auxiliary drive integrated controller, a second-stage step-down DC-DC module, 24V electrical appliances, 12V electrical appliances, and three 12V batteries. Figure 2 This is a connection diagram of a high-voltage power battery, a first-stage step-down DC-DC module, a high-voltage main and auxiliary drive integrated controller, a second-stage step-down DC-DC module, 24V electrical appliances, 12V electrical appliances, and two 12V batteries. Figure 3 This is a schematic diagram of a module of a power supply device according to an embodiment of this application.

[0020] Figure 4 This is a schematic diagram of the circuit connection when the first switching unit is turned on and the second switching unit is turned off in the power supply device of this application embodiment; Figure 5 This is a schematic diagram of the circuit connection when the first switching unit is open and the second switching unit is on in the power supply device of this application embodiment; Figure 6 This is a schematic diagram of the circuit connection of an example power supply device in an embodiment of this application; Figure 7 This is a schematic diagram of the circuit connection of the relay included in the first switching unit of the power supply device in the embodiment of this application; Figure 8 This is a schematic diagram of the circuit connection of the relay included in the second switching unit of the power supply device in the embodiment of this application; Figure 9 This is a schematic diagram of the circuit connection of the relays included in the first switching unit and the second switching unit in the power supply device of the present application embodiment; Figure 10 This is a schematic diagram showing the circuit connection between the control module and the first battery, the second battery, the first switch unit, and the second switch unit in the power supply device of this application embodiment; Figure 11 This is a schematic diagram of the circuit connection when both the first switching unit and the second switching unit in the power supply device of this application are disconnected. Figure 12 This is a flowchart illustrating one embodiment of the power supply method in this application. Figure 13 This is a flowchart illustrating an example of a power supply method in an embodiment of this application.

[0021] Explanation of icon numbers: 1. High-voltage power battery; 2. First-stage step-down DC-DC module; 3. High-voltage main and auxiliary drive integrated controller; 4. Second-stage step-down DC-DC module; a. First 12V battery; b. Second 12V battery; c. Third 12V battery; 5. 24V electrical appliances; 6. 12V electrical appliances; 100. Power battery; 200. Step-down module; 300. Control module; 400. First switching unit; 500. Second switching unit; 600. First storage battery; 700. Second storage battery; 800. First low-voltage load; 900. Second low-voltage load; KA1, First Relay; KA2, Second Relay; KA3, Third Relay; KA4, Fourth Relay; KB1, Fifth Relay; KB2, Sixth Relay; KB3, Seventh Relay; KB4, Eighth Relay; 310. Voltage detection unit; 320. Control unit; 330. Switch drive unit.

[0022] The objectives, features, and advantages of the embodiments described in this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of the embodiments of this application and are not intended to limit the embodiments of this application.

[0024] To better understand the technical solutions of the embodiments of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0025] In range-extended electric vehicles, the high-voltage electricity output from the power battery can be stepped down to 24V by a DC / DC step-down module, which can then power the vehicle's 24V electrical appliances. Unlike pure electric vehicles, range-extended electric vehicles have an engine, so in addition to 24V, there are inevitably electrical appliances with a working voltage of 12V (such as the oxygen sensor on the engine after-treatment system and the fuel pump that is used in passenger cars).

[0026] Currently, a two-stage step-down power supply architecture is commonly used. The first stage uses a DC / DC converter to step down the high-voltage power from the battery to 24V, and then the second stage uses a DC / DC converter to step down the 24V to 12V, which, together with a separate 12V battery, powers 12V appliances. However, this power supply architecture is complex and requires many components, resulting in higher costs for low-voltage power supplies. For example, refer to... Figure 1 , Figure 1 A schematic diagram of a two-stage step-down power supply architecture is shown. Figure 1The diagram shows a high-voltage power battery 1, a first-stage step-down DC-DC module 2, a high-voltage main and auxiliary drive integrated controller 3, a second-stage step-down DC-DC module 4, three 12V batteries, a 24V appliance 5, and a 12V appliance 6. The three 12V batteries are designated as first 12V battery a, second 12V battery b, and third 12V battery c.

[0027] A high-voltage main and auxiliary drive integrated controller can be a controller that integrates main drive control, auxiliary drive control, and DC / DC conversion functions. The main drive control is used to control the main drive motor, the auxiliary drive control is used to control auxiliary motors such as the power steering pump motor, and the DC / DC conversion is used to convert the high-voltage power from the battery to 24V low-voltage power.

[0028] While there are implementations that reduce the number of 12V batteries to simplify the structure, the presence of two step-down DC-DC modules still results in a relatively complex architecture and higher cost. For example, one could refer to... Figure 2 , Figure 2 The diagram illustrates the circuit connection when there are two 12V batteries in a two-stage step-down power supply structure. Specifically, Figure 2 The diagram shows a high-voltage power battery 1, a primary step-down DC-DC module 2, a high-voltage main and auxiliary drive integrated controller 3, a secondary step-down DC-DC module 4, two 12V batteries, a 24V appliance 5, and a 12V appliance 6; the two 12V batteries are designated as first 12V battery a and second 12V battery b. Figure 2 As can be seen, the first-level DC / DC step-down module outputs 24V, which is then connected in parallel with the 24V battery pack (composed of 12V battery (1) and 12V battery (2) connected in series) to supply power to 24V appliances. The positive and negative terminals of the 12V battery (2) are also connected to the 12V appliances. The second-level DC / DC step-down module is also connected to the 12V appliances, thereby supplying power to the 12V appliances. Figure 2 The two-stage step-down power supply structure shown still suffers from problems such as complex structure and high cost.

[0029] Therefore, this embodiment proposes a power supply device. In this embodiment, the power battery is connected to the input terminal of the step-down module. The control module controls the first switching unit and the second switching unit to conduct in a time-sharing manner, but not simultaneously. When the first switching unit is on, the step-down module, the first battery, and the second battery are connected in series. When the second switching unit is on, the step-down module, the second battery, and the first battery are connected in series. The output terminal of the step-down module supports connection to a first low-voltage load, and the first battery and the second battery support connection to a second low-voltage load. Thus, this embodiment only requires one step-down module to convert the high-voltage power from the power battery to low voltage. The step-down module can supply power to the first low-voltage load, and can also supply power to the two low-voltage loads. The two batteries supply power to the second low-voltage load. Compared to a two-stage step-down power supply architecture, this reduces the number of step-down modules, simplifies the power supply structure, and thus reduces structural costs. Furthermore, because the first and second switching units are time-divisionally activated, the first and second batteries are alternately connected in series, allowing them to supply power to the second low-voltage load in turn. This balances the charging and discharging levels of the two batteries, avoiding excessive wear caused by a single battery supplying power to the second low-voltage load for an extended period. This extends the battery's lifespan and reduces the increased costs associated with frequent battery replacements due to shortened battery life. In summary, this embodiment can solve the technical problem of excessively high low-voltage power supply costs.

[0030] Based on this, the embodiments of this application provide a power supply device, referring to... Figure 3 , Figure 3 This is a schematic diagram of the power supply device according to an embodiment of this application. The power supply device includes a power battery 100, a step-down module 200, a control module 300, a first storage battery 600, a second storage battery 700, a first switching unit 400, and a second switching unit 500; The power battery 100 is connected to the input terminal of the step-down module 200, the control terminal of the first switching unit 400 is connected to the first output terminal of the control module 300, and the control terminal of the second switching unit 500 is connected to the second output terminal of the control module 300. The control module 300 is used to control the first switch unit 400 and the second switch unit 500 to be turned on in a time-sharing manner, and the first switch unit 400 and the second switch unit 500 are not turned on at the same time; When the control module 300 controls the first switching unit 400 to be turned on, the step-down module 200, the first storage battery 600 and the second storage battery 700 are connected in sequence. When the control module 300 controls the second switching unit 500 to be turned on, the step-down module 200, the second battery 700 and the first battery 600 are connected in sequence; The output of the step-down module 200 supports connection to a first low-voltage load 800, and a second low-voltage load 900 is supported between the first battery 600 and the second battery 700.

[0031] It should be noted that the power battery 100 is the vehicle's high-voltage power supply, capable of meeting the vehicle's high and low voltage power requirements. The step-down module 200 can be a DC-DC step-down module, used to convert the high-voltage electricity output from the power battery 100 into 24V low-voltage electricity. The step-down module 200 directly supplies power to the first low-voltage load 800 by converting the high-voltage electricity output from the power battery 100 into 24V low-voltage electricity.

[0032] Both the first battery 600 and the second battery 700 can be 12V batteries. The first switching unit 400 includes multiple relays, and the second switching unit 500 also includes multiple relays. The relays of the first switching unit 400 and the second switching unit 500 are arranged between the first battery 600, the second battery 700, the step-down module 200, and the second low-voltage load 900. The voltage required by the first low-voltage load 800 is greater than the voltage required by the second low-voltage load 900. For example, the first low-voltage load 800 can be a 24V appliance, and the second low-voltage load 900 can be a 12V appliance.

[0033] The control module 300 controls the first switching unit 400 and the second switching unit 500 to conduct in a time-sharing manner but not simultaneously, thereby enabling the two batteries to alternate positions in the series circuit. This allows the two batteries to take turns being positioned near the output terminal of the step-down module 200, balancing the charging and discharging levels of the two batteries, preventing overuse of any single battery, and thus extending battery life and reducing maintenance and replacement costs. In this embodiment, the control module 300 can be integrated into either the vehicle's 12V controller or 24V controller; this embodiment does not specifically limit its integration.

[0034] In this embodiment, the step-down module 200 can also be connected to the control module 300, thereby providing power to the control module 300. Figure 3 The connection between the step-down module 200 and the control module 300 is not shown. The first battery 600 and the second battery 700 can be connected in series to form a battery pack, which can be connected in parallel across the first low-voltage load 800, thereby also supplying power to the first low-voltage load 800.

[0035] For example, you can refer to Figure 4 , Figure 4 This diagram illustrates the circuit connections between the power battery 100, the step-down module 200, the first storage battery 600, the second storage battery 700, the first low-voltage load 800, and the second low-voltage load 900 when the first switching unit 400 is on and the second switching unit 500 is off. Figure 4 As can be seen, the step-down module 200 is directly connected to the first battery 600, which in turn is connected to the second battery 700. A second low-voltage load 900 can be connected between the first battery 600 and the second battery 700, thereby providing power to the second low-voltage load 900. In this embodiment, the first low-voltage load 800, the first battery 600, and the second battery 700 can be integrated into one unit. The step-down module 200 in this embodiment is a single-stage DC-DC step-down module, and the voltage output by the step-down module 200 in this embodiment is the voltage required by the first low-voltage load 800. For example, the step-down module 200 outputs a 24V voltage.

[0036] You can also refer to Figure 5 , Figure 5 This diagram illustrates the circuit connections between the power battery 100, the step-down module 200, the first storage battery 600, the second storage battery 700, the first low-voltage load 800, and the second low-voltage load 900 when the first switching unit 400 is off and the second switching unit 500 is on. Figure 5 As can be seen, the step-down module 200 is directly connected to the second battery 700, and the second battery 700 is then connected to the first battery 600. A second low-voltage load 900 can be connected between the second battery 700 and the first battery 600, thereby providing power to the second low-voltage load 900.

[0037] In this embodiment, the first switching unit 400 and the second switching unit 500 can be turned off simultaneously, and the relays included in the first switching unit 400 and the second switching unit 500 can both be high-speed relays.

[0038] In this embodiment, there are at least two ways to control the first switching unit 400 and the second switching unit 500 to conduct in a time-division manner. For example, there can be a first implementation method and a second implementation method, respectively: The first implementation includes: determining either the first switching unit 400 or the second switching unit 500 as a target first unit, and determining a target second unit from among the first switching unit 400 and the second switching unit 500, wherein the target first unit and the target second unit are different. The target first unit is controlled to be on for a preset first duration, and the target second unit is controlled to be off for a preset first duration. After the target first unit is on for the preset first duration, the target first unit is controlled to be off for a preset second duration, and the target second unit is controlled to be on for a preset second duration. After the target second unit is on for the preset second duration, the process returns to the step of controlling the target first unit to be on for the preset first duration.

[0039] The preset first duration and the preset second duration can be the same or different. This embodiment does not specifically limit this, and the specific duration can be determined based on the actual situation. The preset first duration and the preset second duration can also be set based on the current time period of the vehicle. In other embodiments, they can also be set based on the vehicle's operating status, which can include the power consumption of 12V electrical appliances on the vehicle. Therefore, when the power consumption of 12V electrical appliances is too high, such as exceeding a preset power consumption threshold, the preset first duration and the preset second duration can be set to be relatively short. For example, both the preset first duration and the preset second duration can be... The voltage is set below a preset short duration threshold, thus preventing the first battery 600 or the second battery 700 from being in a state of excessively low voltage for an extended period. When the power consumption of 12V appliances is low, for example, below a preset power consumption threshold, both the preset first duration and the preset second duration can be set to be relatively long, thereby reducing switching. For example, both the preset first duration and the preset second duration can be greater than the preset long duration threshold, and the preset short duration threshold is less than the preset long duration threshold. The preset short duration threshold and the preset long duration threshold can be set based on actual conditions. This embodiment does not impose specific limitations on this, and the specific settings can be determined based on actual conditions.

[0040] The second implementation includes: determining either the first switching unit 400 or the second switching unit 500 as a target on-state unit, and determining a target off-state unit in both the first switching unit 400 and the second switching unit 500, wherein the target on-state unit and the target off-state unit are different; controlling the target on-state unit to be on, and controlling the target off-state unit to be off; after the target on-state unit has been on for a preset power supply duration, controlling the target on-state unit to be off, and detecting the first voltage of the first battery 600 and the second voltage of the second battery 700; based on the first voltage and the second voltage, re-determining the target on-state unit and the target off-state unit in the first switching unit 400 and the second switching unit 500, and returning to the steps of controlling the target on-state unit to be on and controlling the target off-state unit to be off. This second implementation can improve the accuracy of switching between the first switching unit 400 and the second switching unit 500, thereby minimizing the need for switching when the voltages of the first battery 600 and the second battery 700 are too low, thus improving the reliability of the power supply device.

[0041] In addition, for a better understanding of this embodiment, you can also refer to Figure 6 The reason why the first switch unit 400 and the second switch unit 500 need to be time-divisionally turned on in this embodiment is briefly explained: If the vehicle is used for a long time... Figure 6When the circuit connection shown is in operation, the lifespan of the second battery 700 will be significantly reduced because: When I1 > I2: I1 = I2 + I4, the step-down module 200 supplies power to the first low-voltage load 800 and simultaneously charges the first battery 600 and the second battery 700; at this time, I5 = I4 - I3, and the second battery 700 charges slower than the first battery 600; when I1 < I2: I2 = I1 + I4, the step-down module 200 supplies power to the first low-voltage load 800, and the second battery 700 also discharges; at this time, I5 = I4 + I3, and the second battery 700 discharges faster than the first battery 600. Therefore, the second battery 700 charges slower and discharges faster than the first battery 600, and the voltage of the second battery 700 is always lower than the voltage of the first battery 600. If this is maintained for a long time... Figure 6 As shown in the circuit connection diagram, the voltage difference between the first battery 600 and the second battery 700 will remain below the preset voltage difference threshold for an extended period. Over time, this will lead to the second battery 700 becoming undercharged, shortening its lifespan, and causing instability in the power supply voltage to the second low-voltage load 900. Therefore, this embodiment can control the first switching unit 400 and the second switching unit 500 to conduct in a time-sharing manner, allowing the two batteries to alternate positions in the series circuit. This ensures that the two batteries are alternately positioned near the output terminal of the step-down module 200, balancing the charging and discharging levels of the two batteries, preventing overuse of any single battery, thereby extending battery lifespan and reducing maintenance and replacement costs.

[0042] In this embodiment, the power battery 100 in the power supply device is connected to the input terminal of the step-down module 200. The control module 300 controls the first switching unit 400 and the second switching unit 500 to conduct in a time-sharing manner, but not simultaneously. When the first switching unit 400 is on, the step-down module 200, the first battery 600, and the second battery 700 are connected in series. When the second switching unit 500 is on, the step-down module 200, the second battery 700, and the first battery 600 are connected in series. The output terminal of the step-down module 200 supports connection to a first low-voltage load 800, and the first battery 600 and the second battery 700 support connection to a second low-voltage load 900. Thus, this embodiment only requires one step-down module 200 to convert the high voltage of the power battery 100 to low voltage, and the step-down module 200 can provide power to the first low-voltage load. The 800V power supply can simultaneously power a second low-voltage load 900 between the two batteries. Compared to a two-stage step-down power supply architecture, this reduces the number of step-down modules 200, simplifies the power supply structure, and thus reduces structural costs. Furthermore, since the first switching unit 400 and the second switching unit 500 are time-divisionally turned on, the first battery 600 and the second battery 700 are alternately connected in series, allowing the two batteries to take turns powering the second low-voltage load 900. This balances the charging and discharging levels of the two batteries, avoiding excessive wear caused by a single battery powering the second low-voltage load 900 for an extended period. This extends the battery's lifespan and reduces the increased costs associated with frequent battery replacements due to shortened battery life. In summary, this embodiment can solve the technical problem of excessively high low-voltage power supply costs.

[0043] In one feasible embodiment, please refer to Figure 7 and Figure 4 The first switching unit 400 includes a first relay KA1, a second relay KA2, a third relay KA3, and a fourth relay KA4; The control terminals of the first relay KA1, the second relay KA2, the third relay KA3, and the fourth relay KA4 are all connected to the first output terminal of the control module 300. The first terminal of the first relay KA1 is connected to the output terminal of the step-down module 200, and the second terminal of the first relay KA1 is connected to the positive terminal of the first battery 600. The first terminal of the second relay KA2 is connected to the negative terminal of the first battery 600, and the second terminal of the second relay KA2 is connected to the positive terminal of the second battery 700. The first terminal of the third relay KA3 is connected to the negative terminal of the second battery 700, and the second terminal of the third relay KA3 is grounded. The first terminal of the fourth relay KA4 is connected to the positive terminal of the second battery 700, and the second terminal of the fourth relay KA4 supports connection to the second low-voltage load 900.

[0044] In this embodiment, the control module 300 can control the first relay KA1, the second relay KA2, the third relay KA3, and the fourth relay KA4 to be turned on through the first output terminal. For example, the first output terminal can output a low level to turn on the first switching unit 400, and output a high level to turn off the first switching unit 400, or control each relay in the first switching unit 400 to float so that the first switching unit 400 is turned off. In other embodiments, a high level can also be output to turn on the first switching unit 400, and a low level can be output to turn off the first switching unit 400. This embodiment does not specifically limit this, and the specific settings can be based on the actual situation.

[0045] In this embodiment, the first switching unit 400 can be composed of a first relay KA1, a second relay KA2, a third relay KA3, and a fourth relay KA4. When the control module 300 simultaneously controls these four relays to conduct through the first output terminal, the step-down module 200, the first battery 600, and the second battery 700 are connected in series. At this time, the first battery 600 is located near the output terminal of the step-down module 200 in the series circuit, and the second battery 700 is located near the ground terminal. The step-down module 200 outputs 24V to power the first low-voltage load 800, while the positive terminal of the second battery 700 provides 12V power to the second low-voltage load 900 through the fourth relay KA4. All four relays in the first switching unit 400 are driven by the same control signal, thereby ensuring the stability of the power supply to the second low-voltage load 900. For example, in Figure 7 Each control terminal in the first switching unit 400 is connected to z1, where z1 refers to the first output terminal of the control module 300.

[0046] In one feasible embodiment, please refer to Figure 8 and Figure 5 The second switching unit 500 includes a fifth relay KB1, a sixth relay KB2, a seventh relay KB3, and an eighth relay KB4; The control terminals of the fifth relay KB1, the sixth relay KB2, the seventh relay KB3, and the eighth relay KB4 are all connected to the second output terminal of the control module 300. The first terminal of the fifth relay KB1 is connected to the output terminal of the step-down module 200, and the second terminal of the fifth relay KB1 is connected to the positive terminal of the second battery 700. The first terminal of the sixth relay KB2 is connected to the positive terminal of the first battery 600, and the second terminal of the sixth relay KB2 is connected to the negative terminal of the second battery 700. The first terminal of the seventh relay KB3 is connected to the negative terminal of the first battery 600, and the second terminal of the seventh relay KB3 is grounded. The first terminal of the eighth relay KB4 is connected to the negative terminal of the second battery 700, and the second terminal of the eighth relay KB4 supports connection to the second low-voltage load 900.

[0047] It should be noted that the control module 300 can control the fifth relay KB1, the sixth relay KB2, the seventh relay KB3, and the eighth relay KB4 to conduct through the second output terminal. For example, the second output terminal can output a low level to conduct the second switching unit 500, and output a high level to turn off the second switching unit 500, or control each relay in the second switching unit 500 to float so that the second switching unit 500 is turned off. In other embodiments, a high level can be output to conduct the second switching unit 500, and a low level can be output to turn off the second switching unit 500. This embodiment does not specifically limit this, and the specific settings can be based on the actual situation.

[0048] In this embodiment, the second switching unit 500 can be composed of a fifth relay KB1, a sixth relay KB2, a seventh relay KB3, and an eighth relay KB4. When the control module 300 simultaneously controls these four relays to conduct through the second output terminal, the step-down module 200, the second battery 700, and the first battery 600 are connected in series. At this time, the second battery 700 is located near the output terminal of the step-down module 200 in the series circuit, and the first battery 600 is located near the ground terminal. The step-down module 200 outputs 24V to power the first low-voltage load 800, and at the same time, the negative terminal of the second battery 700 provides a 12V power supply circuit to the second low-voltage load 900 through the eighth relay KB4. When the control module 300 controls the second switching unit 500 to be turned off and the first switching unit 400 to be turned on, the four relays included in the second switching unit 500 are simultaneously turned off, and the relays in the first switching unit 400 take over to form another series path, so that the series connection order of the two batteries is rotated. The multiple relays included in the second switching unit 500 are all driven by the same control signal and operate synchronously to ensure the reliability of power supply to the second low-voltage load 900. When the control module 300 controls the first switching unit 400 to be off and the second switching unit 500 to be on, each relay in the second switching unit 500 is turned on, forming another series path, allowing the series connection sequence of the two batteries to alternate. This embodiment can balance the charging and discharging levels of the two batteries, delaying the lifespan degradation caused by a single battery being at a high or low level for a long time, thereby reducing the frequency of battery replacement and long-term operating costs. Additionally, refer to... Figure 8 For example, in Figure 8 Each control terminal in the second switch unit 500 is connected to z2, where z2 refers to the second output terminal of the control module 300.

[0049] To better understand this embodiment, please refer to Figure 9 , Figure 9 A circuit connection diagram is provided for the power supply device, which includes a first switching unit 400 and a second switching unit 500, comprising the power battery 100, the step-down module 200, the first storage battery 600, the second storage battery 700, the first low-voltage load 800, and the second low-voltage load 900. For ease of illustration, [the diagram is omitted here]. Figure 9 The solid gray lines represent the relays included in the first switching unit 400, and the dashed lines represent the relays included in the second switching unit 500.

[0050] The above embodiment provides an implementation in which the first switching unit 400 includes 4 relays and the second switching unit 500 includes 4 relays. When the first switching unit 400 includes 4 relays and the second switching unit 500 includes 4 relays, each relay included in the first switching unit 400 and the second switching unit 500 can be a single-pole single-throw relay.

[0051] In other embodiments, the first switching unit 400 and the second switching unit 500 in the power supply device may be composed of a plurality of single-pole double-throw relays; for example, the plurality of single-pole double-throw relays may include a first double-throw relay, a second double-throw relay, a third double-throw relay and a fourth double-throw relay; each single-pole double-throw relay includes a common terminal, a first terminal and a second terminal.

[0052] In this configuration, the common terminal of the first double-throw relay is connected to the output terminal of the step-down module 200, the first terminal of the first double-throw relay is connected to the positive terminal of the first battery 600, and the second terminal of the first double-throw relay is connected to the positive terminal of the second battery 700. The common terminal of the second double-throw relay is connected to the negative terminal of the first battery 600, the first terminal of the second double-throw relay is connected to the positive terminal of the second battery 700, and the second terminal of the second double-throw relay is grounded.

[0053] The common terminal of the third double-throw relay is connected to the negative terminal of the second battery 700, the first terminal of the third double-throw relay is grounded, and the second terminal of the third double-throw relay is connected to the positive terminal of the first battery 600.

[0054] The common terminal of the fourth double-throw relay supports connection to the second low-voltage load 900. The first terminal of the fourth double-throw relay is connected to the negative terminal of the second battery 700, and the second terminal of the fourth double-throw relay is connected to the positive terminal of the second battery 700.

[0055] The first switching unit 400 includes a first contact group of a first double-throw relay, a first contact group of a second double-throw relay, a first contact group of a third double-throw relay, and a first contact group of a fourth double-throw relay; the first contact group includes a common terminal and a first terminal of a single-pole double-throw relay. The second switching unit 500 includes a second contact group of the first double-throw relay, a second contact group of the second double-throw relay, a second contact group of the third double-throw relay, and a second contact group of the fourth double-throw relay. The second contact group includes a common terminal and a second terminal of a single-pole double-throw relay. In this case, the first switching unit 400 can be turned on by closing the common terminal and the first terminal of each single-pole double-throw relay, and the first switching unit 400 can be turned off by opening the common terminal and the first terminal of each single-pole double-throw relay; the second switching unit 500 can be turned on by closing the common terminal and the second terminal of each single-pole double-throw relay, and the second switching unit 500 can be turned off by opening the common terminal and the second terminal of each single-pole double-throw relay.

[0056] In one feasible embodiment, please refer to Figure 10 The control module 300 includes a voltage detection unit 310, a control unit 320, and a switch drive unit 330; The first detection terminal of the voltage detection unit 310 is connected to the positive terminal of the first battery 600, the second detection terminal of the voltage detection unit 310 is connected to the negative terminal of the first battery 600, the third detection terminal of the voltage detection unit 310 is connected to the positive terminal of the second battery 700, and the fourth detection terminal of the voltage detection unit 310 is connected to the negative terminal of the second battery 700. The output terminal of the voltage detection unit 310 is connected to the input terminal of the control unit 320; The output terminal of the control unit 320 is connected to the input terminal of the switch drive unit 330. The first drive terminal of the switch drive unit 330 is used as the first output terminal of the control module 300, and the second drive terminal of the switch drive unit 330 is used as the second output terminal of the control module 300.

[0057] It should be noted that the voltage detection unit 310 is a detection circuit or device used to collect the voltage at each end of the first battery 600 and the second battery 700. For example, the voltage detection unit 310 can be a voltage sensor or a circuit used to detect the voltage at each end of the battery, etc. This embodiment does not make specific limitations on this.

[0058] The control unit 320 can be an MCU. The control unit 320 is connected to the voltage detection unit 310 and the switch driving unit 330. The switch driving unit 330 can be a switch driving chip, such as a low-side switch chip or a high-side switch chip. This embodiment does not make a specific limitation. In other embodiments, the switch driving unit 330 can also be a switch output circuit that can output high and low levels. This embodiment does not make a specific limitation.

[0059] In this embodiment, the control module 300 can be composed of a voltage detection unit 310, a control unit 320, and a switch drive unit 330. The voltage detection unit 310 collects the voltages at both ends of the first battery 600 and the second battery 700 and sends them to the control unit 320. The control unit 320 determines the switch unit that should be turned on based on the voltage comparison results of the two batteries, and then controls the switch drive unit 330 to turn on the corresponding switch unit. Thus, this embodiment can specifically determine which switch unit to turn on based on the voltage of the two batteries, avoiding one battery from being continuously in a high discharge state due to long-term low voltage, thereby improving the balance of charging and discharging between the two batteries, delaying battery life degradation, and reducing replacement costs and long-term use costs.

[0060] In one feasible embodiment, please refer to Figure 11 The control unit 320 is also used to control the switch drive unit 330 to periodically turn off the first switch unit 400 and the second switch unit 500. When the first switch unit 400 and the second switch unit 500 are turned off, the control unit 320 controls the voltage detection unit 310 to detect the first voltage of the first battery 600 and the second voltage of the second battery 700.

[0061] It should be noted that periodic shutdown refers to the control unit 320 repeatedly putting the first switching unit 400 and the second switching unit 500 into the off state according to a preset time interval. For example, the preset time interval can be a preset power supply duration, which can be set based on actual conditions, such as 5 minutes, or other durations. This embodiment does not specifically limit this. For example, refer to... Figure 11 , Figure 11 The circuit connection status of the power battery 100, step-down module 200, first low-voltage load 800, second low-voltage load 900, first storage battery 600 and second storage battery 700 when both the first switch unit 400 and the second switch unit 500 are disconnected.

[0062] The control unit 320 can achieve periodic shutdown via a built-in timer. For example, a shutdown period can be set, and when the timer expires, a shutdown command is output to the switch driver unit 330, which then controls the first switch unit 400 and the second switch unit 500 to be in the off state. Alternatively, the control unit 320 can achieve periodic shutdown by counting the number of times the first switch unit 400 and the second switch unit 500 are switched on, for example, performing a shutdown after a certain number of switching cycles. This embodiment does not impose a specific limitation on this method, and it can be set based on actual conditions.

[0063] The first voltage refers to the voltage value across the first battery 600 collected by the voltage detection unit 310. The second voltage refers to the voltage value across the second battery 700 collected by the voltage detection unit 310.

[0064] The control unit 320 is also used to control the switch drive unit 330 to periodically turn off the first switch unit 400 and the second switch unit 500. This is applicable when both the first switch unit 400 and the second switch unit 500 include single-pole single-throw relays. In this case, the first switch unit 400 and the second switch unit 500 can be simultaneously in the off state. In this embodiment, the relays included in the first switch unit 400 and the second switch unit 500 can be high-speed relays. For example, the duration for which the first switch unit 400 and the second switch unit 500 are simultaneously in the off state is short, such as 1 ms. During the period when the first switch unit 400 and the second switch unit 500 are simultaneously in the off state, the voltage detection unit 310 can detect the voltage of the first battery 600 and the second battery 700. Since the duration for which the two switch units are simultaneously in the off state is short, it will not affect the power supply to the second low-voltage load 900.

[0065] Control unit 320 controls switch drive unit 330 to periodically turn off first switch unit 400 and second switch unit 500, so that both first switch unit 400 and second switch unit 500 are in the off state, thereby cutting off all electrical connections between first battery 600 and second battery 700 and step-down module 200, first low-voltage load 800 and second low-voltage load 900. In this state, first battery 600 and second battery 700 are neither charged nor discharged, and the current flowing through each battery is close to zero. Voltage detection unit 310 collects the first voltage of first battery 600 and the second voltage of second battery 700 in this state. The measured voltage is the open-circuit voltage of each battery. Since the open-circuit voltage can more accurately reflect the current state of charge of the battery, it can more reliably identify whether there is an imbalance in charging and discharging between the two batteries.

[0066] In other embodiments, when the first switching unit 400 and the second switching unit 500 are composed of multiple single-pole double-throw relays, the first switching unit 400 and the second switching unit 500 will not be simultaneously in the off state. In this case, the voltage of the first battery 600 and the second battery 700 can be detected when the first switching unit 400 or the second switching unit 500 is turned on. For example, it can still be detected periodically.

[0067] In a feasible embodiment, the control unit 320 is further configured to control the switch driving unit 330 to turn off the first switch unit 400 and drive the second switch unit 500 to turn on when the difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference threshold. The control unit 320 is also used to control the switch drive unit 330 to drive the first switch unit 400 to conduct and the second switch unit 500 to turn off when the difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference threshold.

[0068] It should be noted that the preset voltage difference threshold is a threshold value used to determine whether the voltage difference between the first battery 600 and the second battery 700 is too large. The preset voltage difference threshold can be set based on actual conditions, and this embodiment does not impose specific limitations on it. The preset voltage difference threshold is used to identify whether there is a significant charge-discharge imbalance between the first battery 600 and the second battery 700. When the absolute value of the difference between the first voltage and the second voltage reaches or exceeds the preset voltage difference threshold, it indicates that there is a significant difference in the state of charge of the first battery 600 and the second battery 700.

[0069] The control unit 320 can compare the acquired first voltage with the second voltage. When the difference between the first voltage and the second voltage is detected to be greater than or equal to a preset voltage difference threshold, it indicates that the charge or voltage of the first battery 600 is much higher than that of the second battery 700. At this time, the control unit 320 drives the switch drive unit 330 to turn off the first switch unit 400 and drives the second switch unit 500 to turn on. Similarly, when the difference between the second voltage and the first voltage is detected to reach the preset voltage difference threshold, the opposite action is performed: the second switch unit 500 is turned off and the first switch unit 400 is turned on. This can actively and continuously maintain the voltage balance of the two batteries.

[0070] When the voltage difference between the two batteries reaches a preset voltage difference threshold, the control unit 320 prioritizes connecting the battery with the lower voltage to the series circuit near the output terminal of the step-down module 200 for supplemental power, thereby actively reducing the voltage difference between the two batteries. This ensures a stable power supply to the second low-voltage load 900 while slowing down battery lifespan degradation, reducing battery replacement frequency, and lowering long-term operating costs.

[0071] Furthermore, based on the above embodiments of this application, in another embodiment of this application, the same or similar content as the above embodiments can be referred to the above description, and will not be repeated hereafter. On this basis, this embodiment also provides a power supply method applied to the power supply device as described above. The power supply method includes step S10: controlling the first switching unit and the second switching unit in the power supply device to be turned on in a time-sharing manner, so that when the first switching unit is turned on and the second switching unit is turned off, the second low-voltage load is powered through the second storage battery in the power supply device, and when the second switching unit is turned on and the first switching unit is turned off, the second low-voltage load is powered through the first storage battery in the power supply device.

[0072] It should be noted that time-sharing conduction is a working mode in which the control module controls the first and second switching units to conduct separately in different time periods, and not simultaneously.

[0073] The control module can control the first and second switching units to alternately conduct according to a fixed time period. For example, each switching unit can be set to conduct for a preset duration before switching to another switching unit, and the conduction periods of the two switching units do not overlap. The preset duration can be a first preset duration or a second preset duration. In other embodiments, a short transition period in which both the first and second switching units are turned off can be inserted during the switching process between the first and second switching units.

[0074] The control module in the power supply unit can also dynamically determine the switching unit to be turned on in the next round based on the first voltage and the second voltage periodically collected by the voltage detection unit.

[0075] In this embodiment, the power battery in the power supply device is connected to the input terminal of the step-down module. The control module controls the first switching unit and the second switching unit to conduct in a time-sharing manner, but not simultaneously. When the first switching unit is on, the step-down module, the first battery, and the second battery are connected in series. When the second switching unit is on, the step-down module, the second battery, and the first battery are connected in series. The output terminal of the step-down module supports connection to a first low-voltage load, and the first battery and the second battery support connection to a second low-voltage load. Thus, this embodiment only requires one step-down module to convert the high-voltage power from the power battery to low voltage. The step-down module can supply power to the first low-voltage load, and can also supply power to the second low-voltage load between the two batteries. Compared to a two-stage step-down power supply architecture, this low-voltage load power supply reduces the number of step-down modules, simplifies the power supply structure, and thus reduces structural costs. Furthermore, because the first and second switching units are time-divisionally activated, the first and second batteries are alternately connected in series, allowing them to power the second low-voltage load in turn. This balances the charging and discharging levels of the two batteries, avoiding excessive wear caused by a single battery powering the second low-voltage load for an extended period. Consequently, it extends the battery's lifespan and reduces the increased costs associated with frequent battery replacements due to shortened battery life. In summary, this embodiment can solve the technical problem of excessively high low-voltage power supply costs.

[0076] In one feasible embodiment, please refer to Figure 12 Step S10 also includes steps S11 to S14: Step S11: Determine either the first switch unit or the second switch unit as the target conduction unit, and determine the target cut-off unit in the first switch unit and the second switch unit. The target conduction unit and the target cut-off unit are different. Step S12: Control the target conduction unit to conduct and control the target cutoff unit to cut off; It should be noted that the target conducting unit refers to the switch unit that needs to be turned on. The target cutting-off unit refers to another switch unit that needs to be cut off. The target conducting unit and the target cutting-off unit are different. The first switch unit or the second switch unit can be randomly determined as the target conducting unit, and the other as the target cutting-off unit. In other embodiments, when step S11 is executed for the first time, the first switch unit can also be determined as the target conducting unit and the second switch unit as the target cutting-off unit by default. This embodiment does not make specific limitations on this.

[0077] The control unit sends a first control signal to the switch drive unit. The switch drive unit drives the target turn-on unit to turn on according to the first control signal, while not providing a drive signal to the target turn-off unit or actively outputting a turn-off signal, so that the target turn-off unit remains off.

[0078] Step S13: After the target conducting unit has been turned on for a preset power supply duration, the target conducting unit is turned off, and the first voltage of the first battery and the second voltage of the second battery are detected. Step S14: Based on the first voltage and the second voltage, redetermine the target turn-on unit and the target turn-off unit in the first switch unit and the second switch unit, and return to the step of controlling the target turn-on unit to turn on and controlling the target turn-off unit to turn off.

[0079] It should be noted that the preset power supply duration refers to the length of time from when the target conducting unit is turned on to when it is controlled to be turned off. The preset power supply duration can be a fixed duration, such as being set to several hundred milliseconds to several seconds, and is timed by a timer inside the control unit. Once the timer expires, it triggers the shutdown action of the target conducting unit.

[0080] The preset power supply duration can also be a variable duration. For example, it can be dynamically adjusted according to the difference between the first voltage and the second voltage. When the voltage difference between the two batteries is large, the preset power supply duration can be shortened to accelerate the switching frequency. When the voltage difference is small, the power supply duration can be extended to reduce the number of switching actions, thus balancing the efficiency and the lifespan of the switching devices.

[0081] In this embodiment, the conduction state of the target conduction unit can be dynamically adjusted based on the voltage detection results (first voltage and second voltage), so that the power supply device can optimize the conduction selection in real time according to the actual state of charge of the battery, and connect the battery with low voltage to the output terminal close to the step-down module, thereby realizing closed-loop equalization control of charging and avoiding a certain battery from being in an undervoltage state for a long time.

[0082] In a feasible embodiment, step S14 further includes steps S141 to S144: Step S141: If the difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference threshold, determine the second switching unit as the target conduction unit and the first switching unit as the target cut-off unit. It should be noted that when the difference between the first voltage and the second voltage is greater than or equal to the preset voltage difference threshold, it indicates that the voltage of the first battery is significantly higher than that of the second battery, and the second battery is in a relatively under-voltage state. At this time, the second switching unit can be determined as the target conduction unit and the first switching unit as the target cut-off unit, so that the second battery is directly connected to the output terminal of the step-down module in the next cycle.

[0083] Step S142: If the difference between the first voltage and the second voltage is less than a preset voltage difference threshold, determine the first switching unit as the target conducting unit and the second switching unit as the target cutting off unit. It should be noted that when the difference between the first voltage and the second voltage is less than the preset voltage difference threshold, it indicates that the voltage difference between the two batteries is within an acceptable range. At this time, the first switching unit can be determined as the target conducting unit and the second switching unit as the target cutting unit, maintaining or restoring the first battery to the high position in the series circuit (the first battery is directly connected to the output terminal of the step-down module).

[0084] Step S143: If the difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference threshold, determine the first switching unit as the target conducting unit and the second switching unit as the target cutting-off unit. It should be noted that when the difference between the second voltage and the first voltage is greater than or equal to the preset voltage difference threshold, it indicates that the voltage of the second battery is significantly higher than that of the first battery, and the first battery is in a relatively under-voltage state. At this time, the first switching unit can be determined as the target conduction unit and the second switching unit as the target cutoff unit, so that the first battery is directly connected to the output terminal of the step-down module in the next cycle.

[0085] Step S144: If the difference between the second voltage and the first voltage is less than a preset voltage difference threshold, determine the second switching unit as the target turn-on unit and the first switching unit as the target turn-off unit.

[0086] It should be noted that when the difference between the second voltage and the first voltage is less than the preset voltage difference threshold, it indicates that the voltage difference between the two batteries is within an acceptable range. At this time, the second switching unit can be determined as the target conducting unit and the first switching unit as the target cutting unit, maintaining or restoring the second battery to the high position in the series circuit (the second battery is directly connected to the output terminal of the step-down module).

[0087] In other embodiments, if the second voltage is less than or equal to a preset low-voltage threshold, it indicates that the second battery is over-discharged, and thus the second switching unit can be determined as the target turn-on unit and the first switching unit as the target turn-off unit. Similarly, if the first voltage is less than or equal to the preset low-voltage threshold, it indicates that the first battery is over-discharged, and thus the first switching unit can be determined as the target turn-on unit and the second switching unit as the target turn-off unit. When both the second and first voltages are less than the preset low-voltage threshold, either the first or second switching unit can be determined as the target turn-on unit, and the other as the target turn-off unit. Alternatively, the target turn-on and target turn-off units can remain unchanged, ensuring that the switching unit turned on in the next cycle is the same as the switching unit turned on in the previous cycle.

[0088] The preset low-voltage threshold can be set according to the discharge characteristics of the battery. In other embodiments, the preset low-voltage threshold can also be set according to the minimum operating voltage requirement of the second low-voltage load. This embodiment does not specifically limit this. The preset low-voltage threshold is used to identify whether a single battery is in a low-voltage state. When the voltage of a battery drops below the preset low-voltage threshold, even if the voltage difference between the two batteries has not reached the preset voltage difference threshold, the battery needs to be switched to the position near the output terminal of the step-down module in the series circuit for priority charging to prevent it from being damaged due to over-discharge.

[0089] When the voltage of any battery group is lower than or equal to a preset low-voltage threshold, it indicates that the battery is in a state of depletion and urgently needs to be recharged. For example, when the second switch unit is on and the first switch unit is off, if the first voltage is detected to be very low (less than or equal to the preset low-voltage threshold), the first switch unit can be driven to turn on and the second switch unit can be turned off. Conversely, when the first switch unit is on and the second switch unit is off, if the second voltage is detected to be very low (less than or equal to the preset low-voltage threshold), the second switch unit can be driven to turn on and the first switch unit can be turned off, thereby preventing the battery from being damaged due to over-discharge.

[0090] When the voltage of either battery drops below a preset low-voltage threshold, the control unit can preferentially connect that battery to the position closest to the output terminal of the step-down module to prevent damage due to deep discharge. This system can maintain a continuous charge-discharge balance between the two batteries during normal operation, and provide timely over-discharge protection for the battery with excessively low voltage under extreme conditions. This ensures a stable power supply to the second low-voltage load while slowing down battery lifespan degradation, reducing battery replacement frequency and long-term operating costs.

[0091] In another embodiment, when the difference between the first voltage and the second voltage is greater than or equal to a preset differential voltage threshold and the second voltage is less than or equal to a preset low voltage threshold, the second switching unit is determined to be the target turn-on unit and the first switching unit is determined to be the target turn-off unit; when the difference between the first voltage and the second voltage is less than the preset differential voltage threshold and the second voltage is greater than the preset low voltage threshold, the first switching unit is determined to be the target turn-on unit and the second switching unit is determined to be the target turn-off unit. When the difference between the second voltage and the first voltage is greater than or equal to a preset differential voltage threshold, and the first voltage is less than or equal to a preset low voltage threshold, the first switching unit is determined to be the target turn-on unit and the second switching unit is determined to be the target turn-off unit; when the difference between the second voltage and the first voltage is less than a preset differential voltage threshold, and the first voltage is greater than a preset low voltage threshold, the second switching unit is determined to be the target turn-on unit and the first switching unit is determined to be the target turn-off unit.

[0092] To better understand this embodiment, please refer to Figure 13 , Figure 13 A flowchart of this embodiment is provided, including steps X10 to X120: Step X10: Control the first switching unit to be turned on and the second switching unit to be turned off; In step X10, the circuit connection status of the power supply device can be referred to Figure 4 ,exist Figure 4 After operating for a period of time in the circuit connection state shown, the second voltage U2 of the second battery will be lower than the first voltage U1 of the first battery, and the difference between the first voltage and the second voltage will become increasingly larger, that is, (U1-U2) will continue to increase. After step X10, determine step X20: whether the conduction time of the first switching unit is greater than or equal to the preset power supply time. If the conduction time of the first switching unit is less than the preset power supply time, return to step X10. If the conduction time of the first switching unit is greater than or equal to the preset power supply time, execute step X30: disconnect the first switching unit; at this time, both the first and second switching units are in the disconnected state, which can be referred to Figure 11 At this point, the electrical circuit connections between the first battery, the second battery and the step-down module, and between the first battery, the second battery and the electrical appliances (the first low-voltage load and the second low-voltage load) are all disconnected. Additionally, after disconnecting the first switching unit, its conduction duration can be reset to 0, so that the conduction duration can be timed from 0 the next time the first switching unit is turned on, thus facilitating periodic control of the first and second switching units. After step X30, step X40 can be executed: wait for a preset stabilization time. The preset stabilization time can be set based on actual conditions. Then, after the first and second batteries stabilize, ... Figure 11 Under the circuit connection state, the first voltage and the second voltage are acquired. That is, step X50 is executed: detect the first voltage U1 of the first battery and detect the second voltage U2 of the second battery.

[0093] Step X60: If U1-U2 is greater than or equal to a preset differential pressure threshold, and the difference between U1 and U2 is less than the preset differential pressure threshold, then return to step X10. If the difference between U1 and U2 is greater than or equal to the preset differential pressure threshold, then execute step X70: control the second switching unit to turn on and the first switching unit to turn off. In step X70, the circuit connection status of the power supply device can be referenced. Figure 5 ,exist Figure 5After operating for a period of time in the circuit connection state shown, the first voltage U1 will be lower than the second voltage U2, and the difference between the first voltage and the second voltage will become increasingly larger, that is, (U2-U1) will continue to increase. Step X80: The conduction time of the second switching unit is greater than or equal to the preset power supply time. If the conduction time of the second switching unit is less than the preset power supply time, then return to step X70. If the conduction time of the second switching unit is greater than or equal to the preset power supply time, then execute step X90: Disconnect the second switching unit; at this time, both the first and second switching units are in the disconnected state, which can be referred to Figure 11 After step X90, proceed to step X100: wait for a preset stabilization period; after step X100, proceed to step X110: detect the first voltage U1 of the first battery and the second voltage U2 of the second battery; then proceed to step X120: determine whether U2-U1 is greater than or equal to a preset differential pressure threshold. If the difference between U2 and U1 is less than the preset differential pressure threshold, return to step X70; if the difference between U1 and U2 is greater than or equal to the preset differential pressure threshold, proceed to step X10.

[0094] This application also provides a vehicle, which includes the power supply device described above, and the vehicle is also used to implement the power supply method described above.

[0095] The vehicle provided in this application aims to solve the technical problem of high cost of low-voltage power supply. Compared with the prior art, the beneficial effects of the vehicle provided in this application are the same as those of the power supply method provided in the above embodiments, and will not be repeated here.

[0096] The above are merely preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structural or procedural transformations made using the description and drawings of the present application, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present application.

Claims

1. A power supply device, characterized in that, The power supply device includes a power battery, a step-down module, a control module, a first storage battery, a second storage battery, a first switching unit, and a second switching unit; The power battery is connected to the input terminal of the step-down module, the control terminal of the first switching unit is connected to the first output terminal of the control module, and the control terminal of the second switching unit is connected to the second output terminal of the control module. The control module is used to control the first switching unit and the second switching unit to be turned on in a time-sharing manner, wherein the first switching unit and the second switching unit are not turned on at the same time; When the control module controls the first switching unit to be turned on, the step-down module, the first battery, and the second battery are connected in sequence; When the control module controls the second switching unit to be turned on, the step-down module, the second battery, and the first battery are connected in sequence; The output of the step-down module supports connection to a first low-voltage load, and supports connection to a second low-voltage load between the first battery and the second battery.

2. The power supply device as described in claim 1, characterized in that, The first switching unit includes a first relay, a second relay, a third relay, and a fourth relay; The control terminals of the first relay, the second relay, the third relay, and the fourth relay are all connected to the first output terminal of the control module. The first terminal of the first relay is connected to the output terminal of the step-down module, and the second terminal of the first relay is connected to the positive terminal of the first battery. The first terminal of the second relay is connected to the negative terminal of the first battery, and the second terminal of the second relay is connected to the positive terminal of the second battery. The first terminal of the third relay is connected to the negative terminal of the second battery, and the second terminal of the third relay is grounded. The first terminal of the fourth relay is connected to the positive terminal of the second battery, and the second terminal of the fourth relay supports connection to the second low-voltage load.

3. The power supply device as described in claim 1, characterized in that, The second switching unit includes a fifth relay, a sixth relay, a seventh relay, and an eighth relay; The control terminals of the fifth relay, the sixth relay, the seventh relay, and the eighth relay are all connected to the second output terminal of the control module. The first terminal of the fifth relay is connected to the output terminal of the step-down module, and the second terminal of the fifth relay is connected to the positive terminal of the second battery. The first terminal of the sixth relay is connected to the positive terminal of the first battery, and the second terminal of the sixth relay is connected to the negative terminal of the second battery. The first terminal of the seventh relay is connected to the negative terminal of the first battery, and the second terminal of the seventh relay is grounded. The first terminal of the eighth relay is connected to the negative terminal of the second battery, and the second terminal of the eighth relay supports connection to the second low-voltage load.

4. The power supply device as described in claim 1, characterized in that, The control module includes a voltage detection unit, a control unit, and a switch drive unit; The first detection terminal of the voltage detection unit is connected to the positive terminal of the first battery, the second detection terminal of the voltage detection unit is connected to the negative terminal of the first battery, the third detection terminal of the voltage detection unit is connected to the positive terminal of the second battery, and the fourth detection terminal of the voltage detection unit is connected to the negative terminal of the second battery. The output terminal of the voltage detection unit is connected to the input terminal of the control unit; The output terminal of the control unit is connected to the input terminal of the switch drive unit, the first drive terminal of the switch drive unit is used as the first output terminal of the control module, and the second drive terminal of the switch drive unit is used as the second output terminal of the control module.

5. The power supply device as described in claim 4, characterized in that, The control unit is also used to control the switch drive unit to periodically turn off the first switch unit and the second switch unit; When the first switching unit and the second switching unit are turned off, the control unit is used to control the voltage detection unit to detect the first voltage of the first battery and the second voltage of the second battery.

6. The power supply device as described in claim 5, characterized in that, The control unit is also configured to control the switch driving unit to turn off the first switch unit and drive the second switch unit to turn on when the difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference threshold. The control unit is further configured to control the switch driving unit to drive the first switch unit to conduct and turn off the second switch unit when the difference between the second voltage and the first voltage is greater than or equal to the preset voltage difference threshold.

7. A power supply method, characterized in that, Applied to the power supply device as described in any one of claims 1-6, the power supply method includes: The first switching unit and the second switching unit in the power supply device are controlled to be turned on in a time-sharing manner, so that when the first switching unit is turned on and the second switching unit is turned off, the second low-voltage load is powered through the second storage battery in the power supply device, and when the second switching unit is turned on and the first switching unit is turned off, the second low-voltage load is powered through the first storage battery in the power supply device.

8. The power supply method as described in claim 7, characterized in that, The step of controlling the time-division switching of the first switching unit and the second switching unit in the power supply device includes: Either the first switching unit or the second switching unit is determined as the target conduction unit, and a target cutoff unit is determined in the first switching unit or the second switching unit, wherein the target conduction unit is different from the target cutoff unit; The target conduction unit is controlled to conduct, and the target cutoff unit is controlled to cut off; After the target conducting unit has been powered on for a preset power supply duration, the target conducting unit is controlled to be turned off, and the first voltage of the first battery and the second voltage of the second battery are detected. Based on the first voltage and the second voltage, the target turn-on unit and the target turn-off unit are re-determined in the first switch unit and the second switch unit, and the steps of controlling the target turn-on unit to turn on and controlling the target turn-off unit to turn off are returned.

9. The power supply method as described in claim 8, characterized in that, The step of re-determining the target on-state unit and the target off-state unit in the first switching unit and the second switching unit based on the first voltage and the second voltage includes: If the difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference threshold, the second switching unit is determined to be the target conducting unit, and the first switching unit is determined to be the target cutting-off unit. If the difference between the first voltage and the second voltage is less than a preset voltage difference threshold, the first switching unit is determined to be the target conducting unit and the second switching unit is determined to be the target cutting-off unit. If the difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference threshold, the first switching unit is determined to be the target conducting unit and the second switching unit is determined to be the target cutting-off unit. If the difference between the second voltage and the first voltage is less than the preset voltage difference threshold, the second switching unit is determined to be the target conducting unit, and the first switching unit is determined to be the target cutting-off unit.

10. A vehicle, characterized in that, The vehicle includes a power supply device as described in any one of claims 1-6, and the vehicle is further configured to implement a power supply method as described in any one of claims 7-9.

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