Low-voltage power supply system and vehicle

Abstract

The utility model discloses a low-voltage power supply system and a vehicle. The low-voltage power supply system comprises a first battery unit, a plurality of second battery units and a voltage conversion device. The working voltages of the plurality of second battery units are different; a first end of the voltage conversion device is connected with the first battery unit, a plurality of second ends of the voltage conversion device are correspondingly connected with the plurality of second battery units, and the voltage conversion device is used for converting a first voltage output by the first battery unit into a second voltage required by at least one second battery unit according to a power supply demand; the value of the second voltage is smaller than that of the first voltage. The system can supply power to a plurality of second battery units at the same time, avoids multi-stage energy transmission, improves the energy conversion efficiency, reduces the system cost, and improves the power supply reliability.

Description

Technical Field

[0001] This utility model relates to the field of vehicles, and in particular to a low-voltage power supply system and a vehicle. Background Technology

[0002] In related technologies, the low-voltage power supply system of a vehicle uses a voltage conversion device to convert the energy of the high-voltage battery into a voltage to charge the low-voltage battery. Then, this low-voltage battery outputs different voltages through different voltage conversion devices to charge other low-voltage batteries and loads. This multi-stage energy transmission results in low vehicle power utilization and low efficiency. Moreover, this series architecture has low reliability. If the first stage fails, other systems will also fail, thus paralyzing the entire low-voltage system. In addition, multiple voltage conversion devices increase the cost of the vehicle system. Utility Model Content

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a low-voltage power supply system that can simultaneously power multiple second battery units, avoiding multi-stage energy transmission, improving energy conversion efficiency, reducing system costs, and enhancing power supply reliability.

[0004] The second objective of this utility model is to propose a vehicle.

[0005] To address the aforementioned problems, a first aspect of this utility model provides a low-voltage power supply system, comprising: a first battery unit; a plurality of second battery units, the plurality of second battery units having different operating voltages; and a voltage conversion device, wherein a first terminal of the voltage conversion device is connected to the first battery unit, and a plurality of second terminals of the voltage conversion device are correspondingly connected to the plurality of second battery units, the voltage conversion device being used to convert a first voltage output by the first battery unit into a second voltage required by at least one of the second battery units according to power supply requirements, wherein the value of the second voltage is less than the value of the first voltage.

[0006] According to the low-voltage power supply system of this utility model embodiment, the high-voltage electricity output by the first battery unit is converted into low-voltage electricity that can supply power to multiple second battery units through a voltage conversion device. The low-voltage electricity output by the voltage conversion device supplies power to multiple second battery units simultaneously, avoiding multi-stage energy transmission, improving energy conversion efficiency, reducing system cost, and improving power supply reliability.

[0007] In some embodiments, the voltage conversion device includes: a transformer, the transformer including a primary coil and multiple sets of secondary coils; a primary-side circuit, a first terminal of the primary-side circuit being connected to the primary coil, a second terminal of the primary-side circuit being connected to the first battery cell, the primary-side circuit being used to convert a DC signal corresponding to the first voltage into an AC signal; and multiple secondary-side circuits, the first terminals of the multiple secondary-side circuits being connected to the multiple sets of secondary coils respectively, the second terminal of each secondary-side circuit being connected to a corresponding second battery cell, the secondary-side circuit being used to convert the AC signal into a DC signal corresponding to the second voltage.

[0008] In some embodiments, each group of secondary coils includes a primary coil and a secondary coil, wherein the second end of the primary coil and the first end of the secondary coil are connected to a common terminal, and the common terminal is connected to the first end of the corresponding second battery cell through an inductor.

[0009] In some embodiments, each of the secondary circuits includes: a first secondary sub-circuit, a first terminal of which is connected to a first terminal of the primary coil, and a second terminal of which is connected to a second terminal of the corresponding second battery cell, the first secondary sub-circuit being turned on during a first half-cycle of the drive signal; and a second secondary sub-circuit, a first terminal of which is connected to a second terminal of the secondary coil, and a second terminal of which is connected to a second terminal of the corresponding second battery cell, the second secondary sub-circuit being turned on during a second half-cycle of the drive signal.

[0010] In some embodiments, both the first sub-side circuit and the second sub-side circuit include at least one switching device.

[0011] In some embodiments, both the first sub-circuit and the second sub-circuit include a plurality of switching devices, which are connected in parallel.

[0012] In some embodiments, each group of secondary coils includes one secondary coil; each secondary circuit includes a plurality of first bridge arms connected in parallel, a first end of each first bridge arm being connected to a first end of a corresponding second battery cell, a second end of each first bridge arm being connected to a second end of a corresponding second battery cell, and the midpoint of the plurality of first bridge arms being connected to one of the secondary coils.

[0013] In some embodiments, the primary-side circuit includes a plurality of second bridge arms connected in parallel, a first end of each second bridge arm being connected to a first end of the first battery cell, a second end of each second bridge arm being connected to a second end of the first battery cell, and the midpoint of the plurality of second bridge arms being connected to the primary coil.

[0014] In some embodiments, the primary-side circuit includes two second bridge arms, each comprising: a first switching device and a second switching device, wherein a first end of the first switching device is connected to a first end of the first battery cell, a second end of the first switching device is connected to a first end of the second switching device, a second end of the second switching device is connected to a second end of the first battery cell, a first midpoint is formed between the second end of the first switching device and the first end of the second switching device, and the first midpoint is connected to a first end of the primary coil; a third switching device and a fourth switching device, wherein a first end of the third switching device is connected to a first end of the first battery cell and a first end of the first switching device, a second end of the third switching device is connected to a first end of the fourth switching device, a second end of the fourth switching device is connected to a second end of the second switching device and a second end of the first battery cell, a second midpoint is formed between the second end of the third switching device and the first end of the fourth switching device, and the second midpoint is connected to a second end of the primary coil.

[0015] In some embodiments, each of the secondary circuits includes: a filter unit, wherein a first end of the filter unit is connected to a first end of the corresponding second battery unit, and a second end of the filter unit is connected to a second end of the corresponding second battery unit.

[0016] In some embodiments, the low-voltage power supply system further includes a battery management module, which is connected to the control terminal of the voltage conversion device and is used to control the operating state of the voltage conversion device according to the power supply requirements.

[0017] In some embodiments, the battery management module is also connected to each of the second battery cells to obtain operational detection information of each of the second battery cells and / or control the charging and discharging states of the second battery cells.

[0018] In some embodiments, the low-voltage power supply system further includes: a low-dropout regulator, a first terminal of which is connected to one of a plurality of second battery cells, a second terminal of which is connected to the battery management module, and the low-dropout regulator is used to provide power to the battery management module.

[0019] A second aspect of this utility model provides a vehicle including the low-voltage power supply system described in the above embodiments.

[0020] According to the vehicle of this utility model embodiment, the high voltage output of the first battery unit in the low voltage power supply system is converted into low voltage that can supply power to multiple second battery units through a voltage conversion device. The low voltage output of the voltage conversion device simultaneously supplies power to multiple second battery units of the vehicle, avoiding multi-stage energy transmission, improving the energy conversion efficiency of the vehicle, reducing the cost of the vehicle, and improving the reliability of power supply.

[0021] In some embodiments, the vehicle further includes at least one domain controller connected to a second battery cell of the low-voltage power supply system.

[0022] In some embodiments, the vehicle further includes at least one low-voltage load connected to the second battery cell or the domain controller.

[0023] In some embodiments, the vehicle further includes a vehicle controller connected to the battery management module of the low-voltage power supply system to send power supply requests.

[0024] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0026] Figure 1 This is a schematic diagram of a low-voltage power supply system according to the present invention;

[0027] Figure 2 This is a schematic diagram of a voltage conversion device circuit according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of a voltage conversion device according to an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of a low-voltage power supply system according to an embodiment of the present invention;

[0030] Figure 5 This is a structural block diagram of a vehicle according to an embodiment of the present utility model;

[0031] Figure 6 This is a structural block diagram of a vehicle according to an embodiment of the present utility model;

[0032] Figure 7 This is a structural block diagram of a vehicle according to an embodiment of the present invention.

[0033] Figure label:

[0034] 2000 vehicles;

[0035] Low-voltage power supply system 1000;

[0036] First battery unit 100; Second battery unit 200; Voltage conversion device 300; Transformer T; Primary coil T0; First primary coil T1; Second primary coil T2; Primary circuit 400; Secondary circuit 500; First secondary sub-circuit 510; Second secondary sub-circuit 520; Second bridge arm 401; First switching device Q1; Second switching device Q3; Third switching device Q2; Fourth switching device Q4; Filter unit C; Battery management module 600; Low dropout regulator 700; Domain controller 21; Vehicle controller 23. Detailed Implementation

[0037] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0038] In existing technologies, as automobiles continue to develop towards intelligent networks, connectivity, and electrification, the demand for low-voltage power supply in vehicles is becoming increasingly complex. To meet the power supply needs of low-voltage loads with different voltages, vehicles are equipped with small batteries of different voltage loads, such as 48V, 24V, and 12V batteries. Addressing the phenomenon of multiple voltage states coexisting between low-voltage batteries and various battery voltages in vehicles, existing low-voltage power supply systems use DC / DC (Direct Current to Direct Current Converter) converters to convert the energy from high-voltage batteries into a voltage to charge low-voltage batteries. This low-voltage battery then outputs different voltages through different low-voltage DC / DC converters to charge other low-voltage batteries and loads. This multi-stage energy transfer results in low vehicle energy utilization and efficiency. Furthermore, this parallel-stage architecture suffers from low reliability; failure of the first stage can cause other systems to fail, paralyzing the entire low-voltage system. Additionally, the cost of various DC / DC converters increases the overall vehicle system cost.

[0039] To address the above problems, the first aspect of this utility model provides a low-voltage power supply system that can simultaneously power multiple second battery units, avoiding multi-stage energy transmission, improving energy conversion efficiency, reducing system costs, and enhancing power supply reliability.

[0040] The following is for reference. Figure 1 A fusion circuit according to a first aspect embodiment of the present invention is described, such as... Figure 1As shown, the low-voltage power supply system 1000 includes: a first battery unit 100, a plurality of second battery units 200, and a voltage conversion device 300.

[0041] The multiple second battery units 200 have different operating voltages, for example, the operating voltage of the second battery unit 200 can be 12V, 24V, 48V, etc.; the first terminal of the voltage conversion device 300 is connected to the first battery unit 100, and the multiple second terminals of the voltage conversion device 300 are correspondingly connected to the multiple second battery units 200. The voltage conversion device 300 is used to convert the first voltage output by the first battery unit 100 into a second voltage required by at least one second battery unit 200 according to the power supply requirements. The value of the second voltage is less than the value of the first voltage.

[0042] Specifically, in the low-voltage power supply system 1000, the voltage conversion device 300 is connected to the first battery unit 100 and multiple second battery units 200 respectively. The first battery unit 100 outputs a first voltage to the voltage conversion device 300, and the voltage conversion device 300 converts the first voltage into a second voltage to power the second battery units 200. The first voltage can be understood as the high voltage output by the first battery unit 100, and the second voltage can be understood as the low voltage required for the second battery units 200 to work.

[0043] For example, in a vehicle, the first battery unit 100 can be a vehicle power battery, and the multiple second battery units 200 can be low-voltage batteries with different output voltages to power the vehicle's low-voltage equipment. The voltage conversion device 300 can be multiple DC / DC converters connected in parallel to convert the high-voltage electricity output by the first battery unit 100 into the low-voltage electricity required for the operation of the multiple second battery units 200.

[0044] For example, this utility model proposes a low-voltage power supply system 1000, which can not only meet the power supply needs of different voltage batteries and loads in the vehicle, but also improve the energy conversion efficiency of the vehicle, greatly reduce system costs, and improve the reliability of power supply.

[0045] When the low-voltage power supply system 1000 is working, the DC / DC converter (voltage conversion device 300) converts the energy of the high-voltage battery (first battery unit 100) into low voltage, thereby charging the storage battery (second battery unit 200). Since the DC / DC converter includes multiple voltage outputs, it can directly charge different storage batteries, thus improving the overall energy conversion efficiency. This allows multiple DC / DC controllers to be integrated together, and the internal communication and control circuits of the DC / DC converters can be reused, reducing the overall system cost. Furthermore, the parallel output of multiple DC / DC converters avoids the low-voltage power supply problem caused by single-stage failure, improving the reliability of the vehicle's low-voltage power supply and making the entire system more robust. The low-voltage storage battery provides energy according to the different load requirements of the vehicle. Integrating different storage batteries together and sharing the same low-voltage battery management system reduces both the size and the cost of the overall low-voltage battery control.

[0046] According to the low-voltage power supply system of this utility model embodiment, the high-voltage electricity output by the first battery unit is converted into low-voltage electricity that can supply power to multiple second battery units through a voltage conversion device. The low-voltage electricity output by the voltage conversion device supplies power to multiple second battery units simultaneously, avoiding multi-stage energy transmission, improving energy conversion efficiency, reducing system cost, and improving power supply reliability.

[0047] In some embodiments, such as Figure 2 As shown, the voltage conversion device 300 includes: a transformer T, a primary circuit 400, and a secondary circuit 500.

[0048] The transformer T includes a primary coil T0 and multiple sets of secondary coils. The first end of the primary circuit 400 is connected to the primary coil T0, and the second end of the primary circuit 400 is connected to the first battery unit 100. The primary circuit 400 is used to convert the DC signal corresponding to the first voltage into an AC signal. The first end of the secondary circuit 500 is connected to multiple sets of secondary coils, and the second end of each secondary circuit 500 is connected to the corresponding second battery unit 200. The secondary circuit 500 is used to convert the AC signal into a DC signal corresponding to the second voltage.

[0049] Specifically, such as Figure 2As shown, the voltage conversion device 300 includes a primary circuit 400, a transformer T, and a secondary circuit 500. The primary circuit 400 is connected to the first battery unit 100, and the secondary circuit 500 is connected to the second battery unit 200. The primary circuit 400 converts the DC signal corresponding to the first voltage output by the first battery unit 100 into an AC signal and transmits it to the transformer T. The transformer T steps down the first voltage and transmits it to the secondary circuit 500. There can be multiple secondary circuits 500, and each secondary circuit 500 is connected to a secondary coil. By setting the number of turns of the secondary coil, the voltage transmitted to the corresponding secondary circuit 500 is different for secondary coils with different numbers of turns. The secondary circuit 500 converts the AC signal into a DC signal corresponding to the second voltage to power the second battery unit 200.

[0050] In some embodiments, such as Figure 2 As shown, each set of secondary coils includes a primary coil T1 and a secondary coil T2.

[0051] In this configuration, the second end of the first-stage coil T1 and the first end of the second-stage coil T2 are connected to form a common terminal, which is then connected to the first end of the corresponding second battery unit 200 via an inductor.

[0052] Specifically, the second terminal of the first-stage coil T1 and the common terminal of the second-stage coil T2 are connected to the corresponding second battery unit 200 through an inductor. The common terminal reduces the number of connection points and improves reliability. The inductor can be used for filtering, current limiting or energy buffering. At the same time, the inductor limits current surges, provides isolation for the transformer T, and ensures system safety.

[0053] In some embodiments, such as Figure 2 As shown, each secondary circuit 500 includes: a first secondary sub-circuit 510 and a second secondary sub-circuit 520.

[0054] The first terminal of the first sub-circuit 510 is connected to the first terminal of the first primary coil T1, and the second terminal of the first sub-circuit 510 is connected to the second terminal of the corresponding second battery unit 200. The first sub-circuit 510 is used to conduct during the first half-cycle of the drive signal. The first terminal of the second sub-circuit 520 is connected to the second terminal of the second primary coil T2, and the second terminal of the second sub-circuit 520 is connected to the second terminal of the corresponding second battery unit 200. The second sub-circuit 520 is used to conduct during the second half-cycle of the drive signal.

[0055] Specifically, the secondary circuit 500 divides the drive signal into a first half-cycle (positive half-cycle or the beginning of the duty cycle) and a second half-cycle (negative half-cycle or the end of the duty cycle), respectively controlling the conduction of the first secondary sub-circuit 510 and the second secondary sub-circuit 520. The first secondary sub-circuit 510 conducts only during the first half-cycle, supplying power to the second battery unit 200, while the second secondary sub-circuit 520 conducts only during the second half-cycle, supplying power to the second battery unit 200 during the other half-cycle.

[0056] The conduction times of the first sub-circuit 510 and the second sub-circuit 520 are complementary, avoiding direct short circuits and achieving full-cycle energy output.

[0057] In some embodiments, such as Figure 2 As shown, both the first sub-circuit 510 and the second sub-circuit 520 include at least one switching device.

[0058] Specifically, the switching devices in the first sub-circuit 510 and the second sub-circuit 520 can be MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). By controlling the switching devices, the first sub-circuit 510 and the second sub-circuit 520 can be switched on and off.

[0059] In some embodiments, such as Figure 2 As shown, both the first sub-circuit 510 and the second sub-circuit 520 include multiple switching devices, which are connected in parallel.

[0060] Specifically, such as Figure 2 As shown, the first sub-circuit 510 includes Q11, Q12, Q13, and Q14, and the second sub-circuit 520 includes Q15, Q16, Q17, and Q18. There can be multiple sub-circuits 500, each including the first sub-circuit 510 and the second sub-circuit 520. Each first sub-circuit 510 and the second sub-circuit 520 includes four switching devices. Figure 2 As shown, the low-voltage power supply system 1000 includes three secondary circuits 500. More secondary circuits 500 can be set according to specific needs, such as 5, 7, 9 or N secondary circuits 500. Each secondary circuit 500 includes four switching devices in its first secondary sub-circuit 510 and second secondary sub-circuit 520. By controlling the conduction of the switching devices, the first secondary sub-circuit 510 is turned on in the first half-cycle, and the second secondary sub-circuit 520 is turned on in the second half-cycle of the drive signal.

[0061] In some embodiments, each group of secondary coils includes one secondary coil.

[0062] Specifically, in Figure 2 The secondary coil is provided with a primary coil T1 and a secondary coil T2. Alternatively, only one secondary coil can be designed to supply power to the second battery unit 200, but the circuit reliability will be reduced.

[0063] remove Figure 2 In addition to the connection method of the secondary circuit 500 shown, each secondary circuit 500 may include multiple first bridge arms.

[0064] Among them, multiple first bridge arms are connected in parallel, and Figure 2 The bridge arms in the Zhongyuan side circuit 400 are connected in the same way. The first end of each first bridge arm is connected to the first end of the corresponding second battery unit 200, the second end of each first bridge arm is connected to the second end of the corresponding second battery unit 200, and the midpoint of multiple first bridge arms is connected to a secondary coil.

[0065] Specifically, each secondary circuit 500 includes two first bridge arms, each first bridge arm includes two switching devices, and each secondary circuit 500 includes four switching devices. The four switching devices form two first bridge arms. Alternating voltage is generated by alternately turning on the first bridge arms. The secondary circuit 500 achieves flexible voltage / current distribution, redundancy backup, and isolation enhancement through the coordinated operation of multiple sets of switching devices.

[0066] In some embodiments, such as Figure 2 As shown, the primary-side circuit 400 includes multiple second bridge arms 401.

[0067] In this configuration, multiple second bridge arms 401 are connected in parallel. The first end of each second bridge arm 401 is connected to the first end of the first battery unit 100, the second end of each second bridge arm 401 is connected to the second end of the first battery unit 100, and the midpoint of the multiple second bridge arms 401 is connected to the primary coil T0.

[0068] Specifically, such as Figure 2 As shown, the primary circuit 400 includes two sets of second bridge arms 401. The two sets of second bridge arms 401 work together to achieve flexible power distribution of the input voltage and suppression of electromagnetic interference. The two sets of second bridge arms 401 in the primary circuit 400 are alternately turned on to convert the DC signal output by the first battery unit 100 into an AC signal, which is coupled to multiple secondary circuits 500 through the transformer T.

[0069] In some embodiments, such as Figure 2 As shown, the primary-side circuit 400 includes two second bridge arms 401; the two second bridge arms 401 include: a first switching device Q1, a second switching device Q3, a third switching device Q2 and a fourth switching device Q4.

[0070] Specifically, the first end of the first switching device Q1 is connected to the first end of the first battery unit 100, the second end of the first switching device Q1 is connected to the first end of the second switching device Q3, the second end of the second switching device Q3 is connected to the second end of the first battery unit 100, there is a first midpoint between the second end of the first switching device Q1 and the first end of the second switching device Q3, and the first midpoint is connected to the first end of the primary coil T0.

[0071] The first end of the third switching device Q2 is connected to the first end of the first battery unit 100 and the first end of the first switching device Q1. The second end of the third switching device Q2 is connected to the first end of the fourth switching device Q4. The second end of the fourth switching device Q4 is connected to the second end of the second switching device Q3 and the second end of the first battery unit 100. There is a second midpoint between the second end of the third switching device Q2 and the first end of the fourth switching device Q4. The second midpoint is connected to the second end of the primary coil T0.

[0072] In some embodiments, such as Figure 2 As shown, each secondary circuit 500 includes a filter unit C.

[0073] The first end of the filter unit C is connected to the first end of the corresponding second battery unit 200, and the second end of the filter unit C is connected to the second end of the corresponding second battery unit 200.

[0074] Specifically, the filter unit C can be a filter capacitor. The function of the filter unit C is to convert the pulsating DC or AC voltage output by the transformer T into a stable DC output through energy buffering and voltage smoothing. Therefore, each secondary circuit 500 includes a filter unit C to stabilize the current entering and exiting the second battery unit 200.

[0075] For example, a schematic diagram of the voltage conversion device 300 in the low-voltage power supply system 1000 is shown below. Figure 2 As shown, Q1-Q4 are the 400 power MOSFETs in the primary circuit of the voltage conversion device 300, which are high-voltage side MOSFETs; Q11-Qn8 are the 500 power MOSFETs in the secondary circuit, which are low-voltage side MOSFETs. The number of low-voltage side MOSFETs can be selected according to different low-voltage load power requirements. The vehicle controller outputs PWM (Pulse Width Modulation) waves to control Q1-Q4 and Q11-Qn8 to operate in different states. T is the transmission transformer, and different output voltages are achieved by designing different transformer turns ratios. C is the low-voltage output filter capacitor, and different solutes can be selected according to different output voltages and currents to remove ripple current. Figure 2As shown, the three secondary circuits 500 share the primary circuit 400, and the communication module and vehicle controller module of each secondary circuit 500 can be reused, thus reducing the cost of the communication module and the low-voltage control module.

[0076] This utility model provides a low-voltage power supply system, such as Figure 1 As shown, the first battery unit 100 mainly provides energy. The voltage conversion device 300 converts the energy of the first battery unit 100 into low voltage to charge the second battery unit 200. The second battery unit 200 provides energy to different low-voltage loads of the vehicle. The domain controller synchronously collects the demand of different low-voltage loads for power distribution and scheduling.

[0077] The specific process is as follows: Figure 3 As shown, the first battery cell 100 is connected to the primary circuit 400 in the voltage conversion device 300. The first secondary circuit converts high voltage electricity into a low voltage electricity in the vehicle system. The second secondary circuit converts high voltage electricity into another low voltage electricity in the vehicle system. The nth secondary circuit converts high voltage electricity into the nth low voltage electricity in the vehicle system.

[0078] The vehicle controller primarily receives power requirements from the communication module and controls the primary circuit 400, the first secondary circuit, the second secondary circuit, and the nth secondary circuit to output different voltage and power requirements. Specifically, the vehicle controller collects high-voltage and current information from the voltage conversion device 300, as well as low-voltage and current information, and controls the output of different PWM duty cycles to produce different low-voltage voltages and currents. The communication module mainly receives voltage and current information from the vehicle's power grid and transmits it to the vehicle controller, enabling the vehicle controller to control the primary circuit 400 and the secondary circuit 500 in the voltage conversion device 300.

[0079] In some embodiments, such as Figure 4 As shown, the low-voltage power supply system 1000 also includes a battery management module 600.

[0080] The battery management module 600 is connected to the control terminal of the voltage conversion device 300 and is used to control the working state of the voltage conversion device 300 according to the power supply requirements.

[0081] Specifically, the battery management module 600 through Figure 2 The resistors shown are connected to the control terminals of each switch in the secondary circuit 500, and the battery management module 600 is also connected to the control terminals of each switch in the primary circuit 400. The battery management module 600 can send drive signals to control the on / off state of each switch according to the charging demand, thereby charging one or more low-voltage batteries.

[0082] In some embodiments, such as Figure 4As shown, the battery management module 600 is also connected to each of the second battery cells 200 to obtain the working detection information of each of the second battery cells 200 and / or control the charging and discharging state of the second battery cells 200.

[0083] Specifically, the battery management module 600 can acquire the voltage and current information of each second battery cell 200. Based on the acquired detection information, the battery management module 600 controls the working state of the second battery cell 200 to achieve overcurrent protection for the second battery cell 200 and improve the safety of the low-voltage power supply system 1000.

[0084] In some embodiments, such as Figure 4 As shown, the low-voltage power supply system 1000 also includes a low-differential voltage regulator 700.

[0085] The first terminal of the low-dropout regulator 700 is connected to one of the multiple second battery cells 200, and the second terminal of the low-dropout regulator 700 is connected to the battery management module 600. The low-dropout regulator 700 is used to provide power to the battery management module 600.

[0086] For example, such as Figure 4 As shown, LV1 is the output of the first secondary circuit 500, which supplies power to the connected second battery unit 200 through a fuse. The overcurrent capacity of the fuse can be selected according to the actual load conditions. LV2 is the output of the second secondary circuit 500, which supplies power to the connected second battery unit 200 through a fuse. The overcurrent capacity of the fuse can be selected according to the actual load conditions. LVn is the output of the nth secondary circuit 500, which supplies power to the connected second battery unit 200 through a fuse. The overcurrent capacity of the fuse can be selected according to the actual load conditions.

[0087] The low-voltage power supply for the battery management module 600 can be selected from any of the second battery cells 200. Generally, the lower the voltage of the selected second battery cell 200, the lower the cost of the entire system. The low-dropout regulator 700 converts the voltage of the second battery cell 200 to a voltage suitable for the operation of the chips in the battery management module 600 system.

[0088] The battery management module 600 collects the vehicle's power demand via CAN (Controller Area Network) communication and simultaneously acquires data such as voltage and current from each of the second battery cells 200. Based on the battery cell's SOC (State of Charge), it controls the switching devices to charge the second battery cells 200. Figure 1 The second battery unit 200 shown supplies power to different loads, such as 48V motors and 12V lighting loads, through a domain controller.

[0089] This utility model's voltage conversion device directly charges the battery, eliminating the need to convert the voltage of the first battery to the voltage of the second battery for charging. According to current industry evaluations, the efficiency of voltage conversion devices is 94%, while the efficiency of two-stage series connection is 88%. Therefore, this utility model can improve efficiency and integrate multiple batteries into one system, sharing a battery management module, which can reduce size and lower system cost.

[0090] The second aspect of this utility model provides a vehicle, such as... Figure 5 As shown, vehicle 2000 includes: low-voltage power supply system 1000.

[0091] According to the vehicle of this utility model embodiment, the high voltage output of the first battery unit in the low voltage power supply system is converted into low voltage that can supply power to multiple second battery units through a voltage conversion device. The low voltage output of the voltage conversion device simultaneously supplies power to multiple second battery units of the vehicle, avoiding multi-stage energy transmission, improving the energy conversion efficiency of the vehicle, reducing the cost of the vehicle, and improving the reliability of power supply.

[0092] In some embodiments, such as Figure 6 As shown, vehicle 2000 also includes at least one domain controller 21.

[0093] At least one domain controller 21 is connected to the second battery unit 200 of the low-voltage power supply system 1000.

[0094] Specifically, such as Figure 1 In the vehicle 2000 shown, the domain controller 21 is connected to the second battery unit 200, and the second battery unit 200 supplies power to different loads through the domain controller 21.

[0095] In some embodiments, the vehicle 2000 also includes at least one low-voltage load.

[0096] Among them, such as Figure 1 As shown, at least one low-voltage load in vehicle 2000 is connected to the second battery unit 200 or the domain controller 21.

[0097] In some embodiments, such as Figure 7 As shown, vehicle 2000 also includes: vehicle controller 23.

[0098] The vehicle controller 23 is connected to the battery management module 600 of the low-voltage power supply system 100 to send power supply requests.

[0099] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, substrate, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0100] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A low-voltage power supply system, characterized in that, include: First battery cell; Multiple second battery cells, each with a different operating voltage; A voltage conversion device is provided, wherein a first terminal of the voltage conversion device is connected to the first battery cell, and a plurality of second terminals of the voltage conversion device are correspondingly connected to a plurality of second battery cells. The voltage conversion device is used to convert a first voltage output by the first battery cell into a second voltage required by at least one second battery cell according to power supply requirements, wherein the value of the second voltage is less than the value of the first voltage.

2. The low-voltage power supply system according to claim 1, characterized in that, The voltage conversion device includes: A transformer, comprising a primary coil and multiple sets of secondary coils; The primary-side circuit has a first terminal connected to the primary coil and a second terminal connected to the first battery cell. The primary-side circuit is used to convert the DC signal corresponding to the first voltage into an AC signal. Multiple secondary circuits are provided, with the first end of each secondary circuit connected to a corresponding set of secondary coils, and the second end of each secondary circuit connected to a corresponding second battery cell. The secondary circuits are used to convert the AC signal into a DC signal corresponding to the second voltage.

3. The low-voltage power supply system according to claim 2, characterized in that, Each set of secondary coils includes a primary coil and a secondary coil. The second end of the primary coil and the first end of the secondary coil are connected to a common terminal. The common terminal is connected to the first end of the corresponding second battery cell through an inductor.

4. The low-voltage power supply system according to claim 3, characterized in that, Each of the secondary-side circuits includes: The first secondary sub-circuit has a first terminal connected to the first terminal of the first primary coil and a second terminal connected to the second terminal of the corresponding second battery cell. The first secondary sub-circuit is used to conduct during the first half-cycle of the drive signal. The second sub-circuit has a first end connected to the second end of the second stage coil and a second end connected to the second end of the corresponding second battery cell. The second sub-circuit is used to conduct during the second half-cycle of the drive signal.

5. The low-voltage power supply system according to claim 4, characterized in that, Both the first and second sub-sub-circuits include at least one switching device.

6. The low-voltage power supply system according to claim 5, characterized in that, Both the first and second sub-circuits include multiple switching devices, which are connected in parallel.

7. The low-voltage power supply system according to claim 2, characterized in that, Each group of secondary coils includes one secondary coil; Each of the secondary circuits includes a plurality of first bridge arms connected in parallel. The first end of each first bridge arm is connected to the first end of the corresponding second battery cell, the second end of each first bridge arm is connected to the second end of the corresponding second battery cell, and the midpoint of the plurality of first bridge arms is connected to the secondary coil.

8. The low-voltage power supply system according to claim 2, characterized in that, The primary circuit includes multiple second bridge arms connected in parallel. The first end of each second bridge arm is connected to the first end of the first battery cell, the second end of each second bridge arm is connected to the second end of the first battery cell, and the midpoint of the multiple second bridge arms is connected to the primary coil.

9. The low-voltage power supply system according to claim 8, characterized in that, The primary-side circuit includes two second bridge arms, and the two second bridge arms include: A first switching device and a second switching device, wherein a first end of the first switching device is connected to a first end of the first battery cell, a second end of the first switching device is connected to a first end of the second switching device, a second end of the second switching device is connected to a second end of the first battery cell, and a first midpoint is located between the second end of the first switching device and the first end of the second switching device, and the first midpoint is connected to a first end of the primary coil. A third switching device and a fourth switching device, wherein the first end of the third switching device is connected to the first end of the first battery cell and the first end of the first switching device, the second end of the third switching device is connected to the first end of the fourth switching device, the second end of the fourth switching device is connected to the second end of the second switching device and the second end of the first battery cell, and there is a second midpoint between the second end of the third switching device and the first end of the fourth switching device, and the second midpoint is connected to the second end of the primary coil.

10. The low-voltage power supply system according to any one of claims 2-9, characterized in that, Each of the secondary-side circuits includes: A filtering unit, wherein the first end of the filtering unit is connected to the first end of the corresponding second battery unit, and the second end of the filtering unit is connected to the second end of the corresponding second battery unit.

11. The low-voltage power supply system according to any one of claims 1-9, characterized in that, The low-voltage power supply system also includes: A battery management module is connected to the control terminal of the voltage conversion device and is used to control the operating state of the voltage conversion device according to the power supply requirements.

12. The low-voltage power supply system according to claim 11, characterized in that, The battery management module is also connected to each of the second battery cells to obtain the working detection information of each of the second battery cells and / or control the charging and discharging state of the second battery cells.

13. The low-voltage power supply system according to claim 11, characterized in that, The low-voltage power supply system also includes: A low-dropout regulator, wherein a first terminal of the low-dropout regulator is connected to one of a plurality of second battery cells, and a second terminal of the low-dropout regulator is connected to the battery management module, and the low-dropout regulator is used to provide power to the battery management module.

14. A vehicle, characterized in that, Includes the low-voltage power supply system as described in any one of claims 1-13.

15. The vehicle according to claim 14, characterized in that, The vehicle also includes at least one domain controller, which is connected to a second battery cell of the low-voltage power supply system.

16. The vehicle according to claim 15, characterized in that, The vehicle also includes at least one low-voltage load, which is connected to the second battery cell or the domain controller.

17. The vehicle according to claim 14, characterized in that, The vehicle also includes a vehicle controller, which is connected to the battery management module of the low-voltage power supply system to send power supply requests.

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