Vehicle low-voltage power supply system, control method and device thereof and vehicle

Abstract

The invention relates to the technical field of automobile control, and discloses a vehicle low-voltage power supply system which comprises a high-voltage power supply, a first voltage conversion module, a power regulation and control capacitor, a second voltage conversion module, a low-voltage energy storage module, a control module and a partial pressure load, and a set of complete power supply system is built. Wherein the power regulation and control capacitor is bidirectionally connected with the two low-voltage buses through the second voltage conversion module to realize bidirectional flow of energy. The instantaneous power impact can be effectively buffered, the voltage fluctuation of the system is reduced and the stability is improved by utilizing the high power density and the rapid charging and discharging capability of the power regulation and control capacitor. The invention further discloses a control method and device for the vehicle low-voltage power supply system and the vehicle.

Description

Technical Field

[0001] The present application relates to the field of automobile control technology, for example, to a vehicle low-voltage power supply system and a control method, device, and vehicle thereof. Background Art

[0002] With the continuous advancement of vehicle electrification and intelligentization, the power demand of low-voltage systems in vehicles is rapidly increasing. Traditional 12V power supply systems are gradually exposing numerous problems when dealing with high-power loads such as cooling fans, power steering, and active suspension. Since current is inversely proportional to voltage for a given power level, these high-energy-consuming devices must withstand currents of up to 250A under a 12V architecture. This necessitates increasing the cross-sectional area of the wiring harness to carry the high current. This not only increases wiring weight but also results in wire losses of up to 10% to 15%, significantly impacting vehicle energy efficiency. The 48V power supply system, on the other hand, significantly reduces current and wiring cross-sectional area for the same power level, improving energy efficiency and supporting a wider power range. Its low voltage ripple also ensures reliable power supply for critical equipment and enables redundant power supply.

[0003] Prior art provides a low-voltage hybrid power supply architecture for vehicles and vehicles. These are connected to a power battery pack via a bidirectional DC-DC circuit. The power distribution circuit, controlled by a master control circuit, controls the direction of energy transfer between the power battery pack and the battery pack, providing a first voltage to a first low-voltage load terminal and a second voltage to a second low-voltage load terminal. This power supply architecture eliminates the need for a low-voltage battery in the vehicle and utilizes the power battery pack to achieve multiple low-voltage power distribution functions. This eliminates the need for replacement and maintenance of low-voltage batteries and eliminates the need to reserve space for batteries within the vehicle structure, facilitating the layout and simplification of the electronic control system.

[0004] Although related technologies already involve hybrid 48V and 12V power supplies for automotive low-voltage systems, these systems are designed around a power battery pack, bidirectional DC-DC circuits, power distribution circuits, and a main control circuit. This eliminates the need for a low-voltage battery and instead utilizes the power battery pack for low-voltage power distribution. When high-power loads start up instantaneously and cause bus voltage fluctuations, the existing architecture lacks the buffering provided by energy storage components, making it difficult to suppress these fluctuations and resulting in poor system stability.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0006] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0007] The embodiments of the present disclosure provide a vehicle low-voltage power supply system and a control method, device, and vehicle thereof, so as to effectively deal with the impact caused by the instantaneous startup or change of high-power loads.

[0008] In some embodiments, the vehicle low-voltage power supply system includes:

[0009] A high-voltage power supply, a first voltage conversion module, a power control capacitor, a second voltage conversion module, a low-voltage energy storage module, a control module, and a voltage-dividing load;

[0010] The high-voltage power supply is electrically connected to the first low-voltage bus and the second low-voltage bus through the first voltage conversion module, and the first voltage conversion module is configured to convert the high-voltage power supply voltage into a first-level voltage and a second-level voltage;

[0011] The power control capacitor is bidirectionally electrically connected to the first low-voltage bus and the second low-voltage bus through the second voltage conversion module, and the second voltage conversion module is configured to support bidirectional flow of energy between the power control capacitor and the two low-voltage buses;

[0012] The low-voltage energy storage module is electrically connected to the second low-voltage bus;

[0013] The divided voltage load is electrically connected to the first low-voltage bus and / or the second low-voltage bus;

[0014] The control module is communicatively connected to the first voltage conversion module, the second voltage conversion module and the voltage-dividing load, and is configured to output a control signal to dynamically select at least one of a high-voltage power supply, a power regulation capacitor and a low-voltage energy storage module as a power supply.

[0015] Here, a complete power supply system is constructed using a high-voltage power supply, a first voltage conversion module, a power-regulating capacitor, a second voltage conversion module, a low-voltage energy storage module, a control module, and voltage-dividing loads. The power-regulating capacitor is bidirectionally connected to two low-voltage busbars via the second voltage conversion module, enabling bidirectional energy flow. When a high-power load starts, the power-regulating capacitor rapidly discharges to provide the required high current. When the load stops or operates at low power, the power-regulating capacitor charges to suppress bus voltage fluctuations. The high power density and rapid charge and discharge capabilities of the power-regulating capacitor effectively buffer transient power surges, reduce system voltage fluctuations, and improve stability. By mitigating transient power surges in the low-voltage system and maintaining its stability, it helps better meet the power and redundancy safety requirements of intelligent driving, smart cabins, and ecological functions. Furthermore, by having the power-regulating capacitor handle the transient high current, the charge and discharge depth and frequency of the low-voltage energy storage module are reduced, extending its service life. Based on load demand and system status, the control module dynamically selects at least one of the high-voltage power supply, power-regulating capacitor, or low-voltage energy storage module as the power source, ensuring stable power supply for both high-power and low-power loads. In addition, the system adopts a 48V and 12V hybrid power supply architecture, avoiding large-scale replacement of existing 12V equipment and reducing the impact on the supply chain and cost pressure.

[0016] Optionally, the first voltage conversion module includes a first buck topology and a second buck topology connected in series;

[0017] The input end of the first buck topology is connected to the output end of the high-voltage power supply, and the output end of the first buck topology is respectively connected to the first low-voltage bus and the input end of the second buck topology; the first buck topology is configured to reduce the voltage of the high-voltage power supply to a first level voltage;

[0018] The output end of the second buck topology is connected to the second bus voltage; the second buck topology is configured to reduce the first level voltage to a second level voltage.

[0019] Here, the first voltage conversion module adopts a two-stage series buck topology. The first buck topology first reduces the high-voltage power supply voltage to the first level voltage, and then the second buck topology reduces the first level voltage to the second level voltage, achieving segmented bucking. This can more accurately control the output voltage and meet the precise voltage requirements of different loads. Compared with single-stage bucking, the segmented buck method can reduce power loss, improve power conversion efficiency, and help improve the energy efficiency of the entire system. At the same time, the two-stage buck topology helps to disperse and manage the buck process of the high-voltage power supply, reduce system complexity and failure risk, and enhance system reliability.

[0020] Optionally, the second voltage conversion module includes a first bidirectional conversion topology and a second bidirectional conversion topology connected in parallel;

[0021] One end of the first bidirectional conversion topology is connected to a power control capacitor, and the other end is connected to a first low-voltage bus; the first bidirectional conversion topology is configured to control the energy transmission direction according to the voltage value of the power control capacitor;

[0022] One end of the second bidirectional conversion topology is connected to the power control capacitor, and the other end is connected to the second low-voltage bus; the second bidirectional conversion topology is configured to control the energy transmission direction according to the voltage value of the power control capacitor.

[0023] Here, the second voltage conversion module uses a first bidirectional conversion topology and a second bidirectional conversion topology in parallel. The first bidirectional conversion topology connects the power control capacitor to the first low-voltage bus, and the second bidirectional conversion topology connects the power control capacitor to the second low-voltage bus. Both control the direction of energy transmission based on the voltage value of the power control capacitor. This enables the power control capacitor to flexibly exchange energy with the two low-voltage buses, improving the system's response speed to instantaneous power demand and ensuring voltage stability.

[0024] Optionally, the voltage-dividing load includes a high-power load electrically connected to the first low-voltage bus and a low-power load electrically connected to the second low-voltage bus.

[0025] In some embodiments, a control method for the above-mentioned vehicle low-voltage power supply system includes:

[0026] Obtain the power supply mode of the vehicle power system; when the vehicle power system is in high-voltage power supply mode, select the power supply source from the power control capacitor and the high-voltage power supply according to the energy storage state of the power control capacitor; when the vehicle power system is not in high-voltage power supply mode, select the power supply source from the power control capacitor and the low-voltage energy storage module according to the load demand level.

[0027] By optimizing the vehicle's power architecture and energy management strategy, the dynamic power source selection strategy can be adjusted based on the system's real-time status, enhancing the system's adaptability to diverse operating conditions and reducing the risk of system failures due to power shortages or overloads. The coordinated operation of multiple power sources, including high-voltage batteries, power-regulating capacitors, and small batteries, ensures a stable power supply for the entire vehicle under diverse operating conditions. Specifically, when integrated into the vehicle's low-voltage power supply system, the power-regulating capacitors significantly enhance the system's transient power supply capabilities through their millisecond-level response speed and high power density. Through rapid charging and discharging, they stabilize the voltage of the vehicle's electrical system, reducing voltage fluctuations during the start-up and shutdown of high-power loads or during operating conditions, thereby protecting the normal operation of onboard equipment. For example, in scenarios with high-frequency power fluctuations, such as intelligent chassis, intelligent driving, and sudden changes in air conditioning loads, the power-regulating capacitors can quickly release stored energy to compensate for voltage drops, reducing the transient discharge current pressure on traditional batteries and extending the service life of lead-acid batteries by over 30%. Furthermore, the vehicle intelligently allocates power tasks based on power supply status and load demand, optimizing the operating status of each power source and further enhancing system stability.

[0028] Optionally, a power supply is selected from the power control capacitor and the high-voltage power supply according to the energy storage state of the power control capacitor, including: if the energy storage state of the power control capacitor meets the instantaneous power support condition, then when the instantaneous power demand is detected, the power control capacitor is controlled to serve as the power supply; if the energy storage state of the power control capacitor does not meet the instantaneous power support condition, then the high-voltage power supply is triggered to serve as the power supply to perform continuous power supply, and the power control capacitor is charged with the remaining available power.

[0029] Optionally, a power supply is selected from the power control capacitor and the low-voltage energy storage module according to the load demand level, including: if there is a high-power level load running, the power supply is determined from the power control capacitor and the low-voltage energy storage module according to the energy storage state of the power control capacitor; if there is no high-power level load running, the low-voltage energy storage module is selected as the power supply to perform continuous power supply.

[0030] Optionally, the power supply is determined in the power control capacitor and the low-voltage energy storage module according to the energy storage state of the power control capacitor, including: when the energy storage state of the power control capacitor is greater than a set threshold, selecting the power control capacitor as the power supply; when the energy storage state of the power control capacitor is less than or equal to the set threshold, selecting the low-voltage energy storage module as the power supply.

[0031] Optionally, the control method for the low-voltage power supply system of the above-mentioned vehicle also includes: when the power of the low-voltage energy storage module is less than the set power value, the intelligent power replenishment mode is operated, and the power control capacitor is used to charge the low-voltage energy storage module. When the high-power load is started, the power control capacitor is discharged quickly to provide the required large current; when the load stops or operates at low power consumption, the power control capacitor is charged to suppress bus voltage fluctuations. The high power density and fast charging and discharging capabilities of the power control capacitor can effectively buffer instantaneous power shocks, reduce system voltage fluctuations, and improve stability. By mitigating the instantaneous power shocks of the low-voltage system and maintaining the stability of the low-voltage system, it is beneficial to better meet the power and redundant safety requirements of intelligent driving, intelligent cabins, and ecological functions.

[0032] In some embodiments, a control device for the above-mentioned vehicle low-voltage power supply system includes a processor and a memory storing program instructions, and the processor is configured to execute the above-mentioned control method when running the program instructions.

[0033] In some embodiments, the vehicle includes a vehicle body; the control device for the vehicle low-voltage power supply system as described above is installed on the vehicle body.

[0034] The vehicle low-voltage power supply system and control method, device, and vehicle provided by the embodiments of the present disclosure can achieve the following technical effects:

[0035] A complete power supply system is built using a high-voltage power supply, a first voltage conversion module, a power-regulating capacitor, a second voltage conversion module, a low-voltage energy storage module, a control module, and a voltage-dividing load. The power-regulating capacitor is bidirectionally connected to the two low-voltage busbars via the second voltage conversion module, enabling bidirectional energy flow.

[0036] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] One or more embodiments are exemplarily described by corresponding drawings. These exemplary descriptions and drawings do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation. In addition,

[0038] Figure 1 This is an architecture diagram of a low-voltage power supply system for a vehicle provided by an embodiment of the present disclosure;

[0039] Figure 2 This is a schematic diagram of a second architecture of a low-voltage power supply system for a vehicle provided by an embodiment of the present disclosure;

[0040] Figure 3 is a circuit diagram of a first voltage conversion module in an embodiment of the present disclosure;

[0041] Figure 4 This is a schematic diagram of a third architecture of a vehicle low-voltage power supply system provided by an embodiment of the present disclosure;

[0042] Figure 5 is a circuit diagram of the second voltage conversion module in an embodiment of the present disclosure;

[0043] Figure 6 is a flow chart of a control method for a vehicle low-voltage power supply system provided by an embodiment of the present disclosure;

[0044] Figure 7 is a second flow chart of a control method for a vehicle low-voltage power supply system provided by an embodiment of the present disclosure;

[0045] Figure 8 2 is a schematic diagram of a control device for a vehicle low-voltage power supply system provided by an embodiment of the present disclosure.

[0046] Reference numerals:

[0047] 100, high-voltage power supply; 200, first voltage conversion module; 300, power control capacitor; 400, second voltage conversion module; 500, low-voltage energy storage module; 600, control module; 700, voltage-dividing load;

[0048] 10. First low-voltage busbar; 20. Second low-voltage busbar;

[0049] 210, first buck topology; 220, second buck topology; 410, first bidirectional conversion topology; 420, second bidirectional conversion topology. DETAILED DESCRIPTION

[0050] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The accompanying drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0051] In the description and claims of the embodiments of the present disclosure, as well as in the accompanying drawings, the terms "first," "second," and the like are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to describe the embodiments of the present disclosure herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0052] Unless otherwise stated, the term "plurality" means two or more.

[0053] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0054] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0055] The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

[0056] Figure 1 This is an architectural diagram of a vehicle low-voltage power supply system provided by an embodiment of the present disclosure.

[0057] like Figure 1 As shown, the vehicle low-voltage power supply system includes: a high-voltage power supply 100, a first voltage conversion module 200, a power control capacitor 300, a second voltage conversion module 400, a low-voltage energy storage module 500, a control module 600, and a voltage-dividing load 700. Solid lines represent electrical connections between modules, and dashed lines represent communication connections between modules.

[0058] The high voltage power supply 100 is electrically connected to the first low voltage bus 10 and the second low voltage bus 20 through the first voltage conversion module 200. The first voltage conversion module 200 is configured to convert the voltage of the high voltage power supply 100 into a first level voltage and a second level voltage.

[0059] High-voltage power supply 100 is the system's main power source, typically the vehicle's power battery pack, and outputs a relatively high DC voltage, typically above 200V. The low-voltage power supply system involved in the embodiments of the present disclosure, where "low voltage" refers to a lower supply voltage than the high-voltage power supply, is typically below 100V in the automotive industry, such as 12V, 24V, or 48V.

[0060] The first voltage conversion module 200, a unidirectional DC-DC converter, is used to reduce the high-voltage power supply voltage to a first-level voltage, typically around 48V, to power high-power loads. It also reduces the first-level voltage to a second-level voltage, typically around 12V, to power low-power loads. The first low-voltage bus 10 corresponds to a first-level voltage of 48V, which is used to power high-power loads such as the vehicle's cooling fan, power steering, and water pump. The second low-voltage bus 20 corresponds to a second-level voltage of 12V, which is used to power the vehicle's 12V loads, including the controller.

[0061] The power control capacitor 300 is bidirectionally electrically connected to the first low-voltage bus 10 and the second low-voltage bus 20 through the second voltage conversion module 400. The second voltage conversion module 400 is configured to support bidirectional flow of energy between the power control capacitor 300 and the two low-voltage buses.

[0062] In this embodiment, the power control capacitor 300 is used to provide the required instantaneous power when the low-voltage load power increases instantaneously, smooth out the low-voltage circuit bus voltage fluctuations, and improve the stability of the low-voltage system. The power control capacitor 300 refers to a capacitor with high power density and fast charging and discharging capabilities, which can absorb or release a large amount of electrical energy in a short period of time, and effectively buffer the instantaneous power impact in the system. Optionally, the power control capacitor 300 in the embodiment of the present disclosure includes a supercapacitor, such as a double-layer capacitor, a Faraday pseudo-capacitor, a hybrid supercapacitor, a MXene-based capacitor, a potassium ion capacitor, etc. In other embodiments of the present application, the power control capacitor 300 may also include a tantalum capacitor, a large-capacity electrolytic capacitor, a ceramic capacitor, and the like having a transient power control function.

[0063] The second voltage conversion module 400 , ie, a bidirectional DC-DC converter, is used to control the bidirectional flow of energy between the power control capacitor 300 and the two low-voltage busbars according to the voltage value of the power control capacitor 300 .

[0064] The low-voltage energy storage module 500 is electrically connected to the second low-voltage bus 20 .

[0065] The low-voltage energy storage module 500, which can be a 12V battery, is connected to the second low-voltage bus 20 and is mainly used to provide stable power for the vehicle's low-voltage control system and some low-power loads when the vehicle is not on high voltage or the power control capacitor 300 is low.

[0066] The voltage-dividing load 700 is electrically connected to the first low-voltage bus and / or the second low-voltage bus.

[0067] The voltage-dividing loads 700 include high-power loads electrically connected to the first low-voltage bus 10 and / or low-power loads electrically connected to the second low-voltage bus 20. Examples of high-power loads include cooling fans, blowers, water pumps, and brake-by-wire systems; and examples of low-power loads include lamps, sensors, and fragrances.

[0068] The control module 600 is communicatively connected to the first voltage conversion module 200, the second voltage conversion module 400 and the voltage-dividing load, and is configured to output a control signal to dynamically select at least one of the high-voltage power supply 100, the power control capacitor 300 and the low-voltage energy storage module 500 as a power supply.

[0069] The control module 600 is used to monitor the vehicle's operating status, the power requirements of various loads, and the power levels of the power control capacitor 300 and the low-voltage energy storage module 500 in real time. Based on this information, it outputs a control signal to dynamically select at least one of the high-voltage power supply 100, the power control capacitor 300, and the low-voltage energy storage module 500 as the power source to meet the power requirements of different loads and ensure stable system operation.

[0070] In this way, through the vehicle low-voltage power supply system provided by the embodiment of the present disclosure, a complete power supply system is built using a high-voltage power supply, a first voltage conversion module, a power control capacitor, a second voltage conversion module, a low-voltage energy storage module, a control module and a voltage-dividing load. Among them, the power control capacitor is bidirectionally connected to the two low-voltage busbars through the second voltage conversion module to achieve bidirectional energy flow. When the high-power load is started, the power control capacitor discharges quickly to provide the required large current; when the load stops or operates at low power consumption, the power control capacitor charges to suppress bus voltage fluctuations. The high power density and fast charging and discharging capabilities of the power control capacitor can effectively buffer instantaneous power shocks, reduce system voltage fluctuations, and improve stability. By mitigating the instantaneous power shocks of the low-voltage system and maintaining the stability of the low-voltage system, it is beneficial to better meet the power and redundancy safety requirements of intelligent driving, intelligent cabin, and ecological functions. On the other hand, by having the power control capacitor take on the task of instantaneous large current, the charging and discharging depth and frequency of the low-voltage energy storage module are reduced, thereby extending its service life. Based on load demand and system status, the control module dynamically selects at least one of the high-voltage power supply, power-regulating capacitors, and low-voltage energy storage module as the power source, ensuring stable power supply for both high- and low-power loads. Furthermore, the system utilizes a hybrid 48V and 12V power supply architecture, avoiding the need to replace existing 12V equipment on a large scale, reducing supply chain impact and cost pressures.

[0071] Figure 2 This is a second architectural diagram of the vehicle low-voltage power supply system provided in an embodiment of the present disclosure.

[0072] like Figure 2 As shown, the vehicle low-voltage power supply system includes: a high-voltage power supply 100, a first voltage conversion module 200, a power control capacitor 300, a second voltage conversion module 400, a low-voltage energy storage module 500, a control module 600 and a voltage-dividing load.

[0073] The first voltage conversion module 200 includes a first buck topology 210 and a second buck topology 220 connected in series;

[0074] The input end of the first buck topology 210 is connected to the output end of the high-voltage power supply 100, and the output end of the first buck topology 210 is respectively connected to the first low-voltage bus 10 and the input end of the second buck topology 220; the first buck topology 210 is configured to reduce the voltage of the high-voltage power supply 100 to a first level voltage;

[0075] The output end of the second buck topology 220 is connected to the second low-voltage bus 20 ; the second buck topology 220 is configured to step down the first-level voltage to a second-level voltage.

[0076] The first step-down topology 210 utilizes a Buck circuit topology and primarily consists of a power switch, a freewheeling diode, a filter inductor, and input and output capacitors. Under the control of a controller, the power switch uses PWM modulation to control its on and off times, chopping and stepping down the voltage of the high-voltage power supply 100. After filtering by the filter inductor and capacitor, the voltage is output as a first-level voltage. The output of the first step-down topology 210 is split into two paths: one connected to the first low-voltage bus 10 and the other connected to the input of the second step-down topology 220. The first-level voltage is 48V, meeting the power supply requirements of high-power loads. The second step-down topology 220, also based on a Buck circuit topology, receives the first-level voltage output from the first step-down topology 210 at its input and further steps it down to a second-level voltage of 12V, primarily used to power low-power loads. The output of the second step-down topology 220 is connected to the second low-voltage bus 20, providing a stable power supply for low-voltage loads.

[0077] The two-stage series buck topology of the first voltage conversion module 200 precisely converts the voltage of the high-voltage power supply 100 into two voltage levels: 48V and 12V, respectively, meeting the power supply requirements of high-power and low-power loads, achieving efficient power supply and reasonable distribution for different load types. Compared to traditional single-voltage power supply systems, this hierarchical power supply approach reduces losses during the power conversion process and improves power conversion efficiency. It is estimated that it can improve the overall system energy efficiency by approximately 15% to 20%. Furthermore, the two-stage buck topology helps to distribute and manage the voltage reduction process of the high-voltage power supply, reducing the complexity and failure risk of single-stage buck circuits. The relatively simple circuitry of each step-down stage facilitates precise control and protection, enhancing system stability. When the load changes, the two-stage buck topology can more quickly and stably adjust the output voltage, ensuring stable system operation. For example, when faced with sudden load changes, the voltage fluctuation amplitude of the system using the two-stage buck topology can be reduced by approximately 30% to 50%, and the recovery time can be shortened by approximately 40% to 60%, compared to a single-stage buck system.

[0078] Specifically, Figure 3 A circuit diagram of the first voltage conversion module 200 in an embodiment of the present disclosure is provided.

[0079] like Figure 3 As shown, the circuit includes a first buck topology 210 and a second buck topology 220. The first buck topology 210 steps down the high voltage of the high voltage power supply HV to a first voltage level, and the second buck topology 220 further steps down the voltage to a second voltage level. The two-stage topology is cascaded via capacitor C2, and the components are connected as follows:

[0080] The first step-down topology 210 adopts a Buck circuit topology structure and includes the following components: capacitor C1, capacitor C2, switch S1, diode S3, diode d1, inductor L1, and resistor R1.

[0081] The + terminal of the 100HV high-voltage power supply is connected to one end of capacitor C1 and the drain of switch S1. The other end of C1 is grounded to filter out high-frequency input ripple. The source of S1 is grounded, and an antiparallel diode D1 is connected between its drain and source to release inductor energy when switch S1 is turned off.

[0082] The drain of the switch S1 is connected to one end of the inductor L1 , and the other end of the inductor L1 is connected in series with the resistor R1 , forming a node A as the output end of the first buck topology 210 .

[0083] The anode of diode S3 is connected to node A, and the cathode is grounded. When switch S1 is turned off, the energy stored in inductor L1 flows to ground through diode S3, maintaining current continuity.

[0084] Node A is connected to one end of capacitor C2, and the other end of capacitor C2 is grounded, filtering the voltage after the first stage of voltage reduction and outputting a stable intermediate voltage.

[0085] A path is branched from node A and connected to the first low-voltage bus (i.e., +48V in the figure) to supply power to the high-power load connected to it.

[0086] The second step-down topology 220 also adopts a Buck circuit topology structure and includes the following components: capacitor C3, switch S2, diode S4, diode d2, inductor L2, and resistor R2.

[0087] The input of the second-stage topology is the output terminal of the first stage, node A (i.e., the midpoint voltage across capacitor C2). Capacitor C2 is connected to one end of resistor R1 (node A), which is then connected to the drain of switch S2. S2's source is grounded, its drain is connected to node A, and an antiparallel diode d2 is connected between its drain and source.

[0088] The drain of the switch tube S2 is connected to one end of the inductor L2 , and the other end of L2 is connected in series with the resistor R2 , forming a node B as the output end of the second buck topology 220 .

[0089] The anode of diode S4 is connected to node B, and the cathode is grounded. When S2 is turned off, the energy stored in L2 flows to ground through S4, maintaining a stable output current.

[0090] Node B is connected to one end of capacitor C3, the other end of C3 is grounded, filters the 12V voltage after the secondary step-down, and outputs a stable DC voltage to the load.

[0091] In this circuit, input current i1 flows from the positive terminal of the high-voltage (HV) supply, through S1 (when on) or d1 (freezing when off), into L1, and then through R1 to node A. i3 branches from node A and connects to the first low-voltage bus 10, supplying high-power loads before returning to ground (the negative terminal of the power supply). The remaining current i2 at node A enters the second-stage buck topology, flows through S2 (when on) or d2 (freezing when off), into L2, and after filtering by R2 and C3, connects to the second low-voltage bus (i.e., 12V in the diagram), supplying low-power loads before returning to ground.

[0092] Specifically, the secondary step-down function of the first voltage conversion module 200 is achieved through the following scheme:

[0093] The first-stage step-down target voltage is set to a first voltage reference value Vref1 = 48V, and the second-stage step-down target voltage is set to a second voltage reference value Vref2 = 12V;

[0094] Real-time acquisition of the first-stage output voltage V1 and the first voltage reference value V ref1 Performing a deviation operation to generate a first voltage error signal; inputting the first voltage error signal into a first proportional integral (PI) regulator to output a first current reference i1; measuring the first branch current i1 on the input side in real time, performing a deviation operation on the first branch current i1 and the first current reference i1 to generate a first current error signal; inputting the first current error signal into a second PI regulator to generate a pulse width modulation signal duty cycle d1 of the first switch tube S1 after operation processing;

[0095] Real-time acquisition of the second-stage output voltage V2 and the second voltage reference value V ref2 Performing a deviation operation to generate a second voltage error signal; inputting the second voltage error signal into a third PI regulator to output a second current reference i2; measuring the second branch current i2 on the input side in real time, performing a deviation operation on the second branch current i2 and the second current reference i2 to generate a second current error signal; inputting the second current error signal into a fourth PI regulator to generate a pulse width modulation signal duty cycle d2 for the second switch tube S2 after operation processing;

[0096] The first branch current i1 and the second branch current i2 satisfy the current superposition relationship: i1=i2+i3, wherein i3 represents the load branch current component, and the value of i1 is greater than i2.

[0097] In this way, the dynamic balance of the two-stage buck circuit is established through the current coupling relationship, so that the intermediate DC bus voltage is stabilized at 48V±ΔV1 and the output end voltage is stabilized at 12V±ΔV2, where ΔV1 and ΔV2 are preset voltage tolerance thresholds.

[0098] The vehicle low-voltage power supply system provided by the embodiment of the present disclosure adopts a two-stage series buck topology, in which the high-voltage power supply voltage is first reduced to a first-level voltage by the first buck topology, and then the first-level voltage is reduced to a second-level voltage by the second buck topology, thereby realizing segmented bucking. This allows for more precise control of the output voltage and meets the precise voltage requirements of different loads. Compared with single-stage bucking, the segmented bucking method can reduce power loss, improve power conversion efficiency, and help improve the energy efficiency of the entire system. At the same time, the two-stage buck topology helps to disperse and manage the buck process of the high-voltage power supply, reduce system complexity and failure risks, and enhance system reliability.

[0099] Figure 4 This is a schematic diagram of the third architecture of the vehicle low-voltage power supply system provided in an embodiment of the present disclosure.

[0100] like Figure 4 As shown, the vehicle low-voltage power supply system includes: a high-voltage power supply 100, a first voltage conversion module 200, a power control capacitor 300, a second voltage conversion module 400, a low-voltage energy storage module 500, a control module 600 and a voltage-dividing load.

[0101] The second voltage conversion module 400 includes a first bidirectional conversion topology 410 and a second bidirectional conversion topology 420 connected in parallel;

[0102] One end of the first bidirectional conversion topology 410 is connected to the power control capacitor 300, and the other end is connected to the first low-voltage bus 10; the first bidirectional conversion topology 410 is configured to control the energy transmission direction according to the voltage value of the power control capacitor 300;

[0103] One end of the second bidirectional conversion topology 420 is connected to the power control capacitor 300 , and the other end is connected to the second low-voltage bus 20 ; the second bidirectional conversion topology 420 is configured to control the energy transmission direction according to the voltage value of the power control capacitor 300 .

[0104] The power-regulating capacitor 300 is a high-capacity capacitor with a capacity far exceeding that of ordinary capacitors, with a typical capacity range of 1F to 5,000F or even exceeding 10,000F. It combines the rapid charge and discharge capabilities of ordinary capacitors with the energy storage capacity of batteries, bridging the gap between electrolytic capacitors and rechargeable batteries. Featuring high power density, rapid charge and discharge capabilities, and a long cycle life, the power-regulating capacitor 300 can absorb or release large amounts of electrical energy in a short period of time, effectively buffering transient power surges in the system. In the second voltage conversion module 400, the power-regulating capacitor 300 is connected to the two low-voltage buses via a parallel first bidirectional conversion topology 410 and a second bidirectional conversion topology 420, enabling flexible energy exchange between the two low-voltage buses. When load power increases transiently, the power-regulating capacitor 300 can quickly release stored energy to meet load demand. When load power decreases or energy is recovered, the power-regulating capacitor 300 can absorb excess energy for recharging, improving the system's response to transient power changes and ensuring voltage stability.

[0105] For example, when a vehicle accelerates or starts, the instantaneous start-up of high-power electrical appliances may cause the bus voltage to drop. The integration of the power control capacitor 300 can control voltage fluctuations within a smaller range. Furthermore, during braking energy recovery, the power control capacitor 300 absorbs some of the recovered energy through a bidirectional conversion topology, enabling rational energy recovery and reuse. By intelligently controlling the direction of energy transmission and ensuring that the power control capacitor 300 charges and discharges at the appropriate times, the system's response speed and stability to instantaneous power changes are further improved.

[0106] Specifically, Figure 5 A circuit diagram of the second voltage conversion module 400 in an embodiment of the present disclosure is provided.

[0107] like Figure 5 As shown, the circuit includes a first bidirectional conversion topology 410 and a second bidirectional conversion topology 420 connected in parallel. Both bidirectional conversion topologies use the power control capacitor 300 as a common input source. That is, the input sides of the two topologies (the part connected to the power control capacitor 300) are connected in parallel, and each independently performs voltage conversion, outputting 48V (i.e., connected to the first low-voltage bus) and 12V voltage (i.e., connected to the second low-voltage bus), respectively.

[0108] The first bidirectional conversion topology 410 includes the following components: capacitor C 11 , capacitor C 12 、Inductor L 11 , switch tube S 11 , switch tube S 12 , freewheeling diode d 11 , freewheeling diode d 12 , resistor R 11 .

[0109] Among them: power control capacitor 300 and capacitor C 11 In parallel, used to stabilize the input voltage. 11 One end is connected to the positive electrode of the power control capacitor 300, and the other end is connected to the switch tube S 11 The drain and diode d 12 Anode of the switch tube S 11 The source of the switch tube S 12 The drain, S 12 The source of the freewheeling diode d is grounded. 11 With S 12 Anti-parallel. Freewheeling diode d 12 Cathode connection resistance R 11 , resistor R 11 The other end is connected to capacitor C 12 , C 12 The two ends output 48V voltage, C 12 The other end is grounded to play a filtering and voltage stabilizing role.

[0110] When the power control capacitor 300 is discharged (supplying power to the 48V side), the current flow in the first bidirectional conversion topology 410 is:

[0111] When the switch tube S 11 When the power is turned on, the current flows out from the positive electrode of the power control capacitor 300 and passes through the inductor L 11 , switch tube S 11 , and then flows back to the negative electrode of the power control capacitor 300. At this time, the inductor L 11 Store energy.

[0112] When the switch tube S 11 When turned off, the inductor L 11 In order to maintain the current, an induced electromotive force is generated. The current flows from the inductor L 11 flows out through diode d 12 , resistor R 11 , for capacitor C 12 It charges and supplies power to the 48V load at the same time, and finally flows back to the negative electrode of the power regulation capacitor 300.

[0113] When the power control capacitor 300 is charged (getting energy from the 48V side), the current flow in the first bidirectional conversion topology 410 is:

[0114] When the switch tube S 12 When it is turned on, the current flows from the 48V power supply (capacitor C 12 ) flows out of the positive electrode and passes through the resistor R 11 、Inductor L 11 , switch tube S 12 , and then flows back to the negative electrode of the 48V power supply (ground terminal).11 Store energy.

[0115] When the switch tube S 12 When turned off, the inductor L 11 Generates induced electromotive force, current flows from inductor L 11 flows out through diode d 11 The power regulating capacitor 300 is charged and finally flows back to the negative electrode of the 48V power supply (ground terminal).

[0116] The second bidirectional conversion topology 420 includes the following components: capacitor C 23 , capacitor C 24 、Inductor L 22 , switch tube S 23 , switch tube S 24 , freewheeling diode d 23 , freewheeling diode d 24 , resistor R 22 .

[0117] Among them, the power control capacitor 300 and the capacitor C 23 Connect in parallel to stabilize the input voltage. 22 One end is connected to the positive electrode of the power control capacitor 300, and the other end is connected to the switch tube S 23 The drain and diode d 24 Anode of the switch tube S 23 The source of the switch tube S 24 The drain, S 24 The source of diode d is grounded. 23 With S 24 Anti-parallel. Diode d 24 Cathode connection resistance R 22 , R 22 The other end is connected to capacitor C 24 , C 24 Output 12V voltage at both ends, C 24 The other end is grounded for filtering and voltage stabilization.

[0118] When the power control capacitor 300 is discharged (supplying power to the 12V side), the current flow in the second bidirectional conversion topology 420 is:

[0119] When the switch tube S 23 When the power is turned on, the current flows out from the positive electrode of the power control capacitor 300, passes through the inductor L22, the switch tube S 23 , and then flows back to the negative electrode of the power control capacitor 300. At this time, the inductor L 22 Store energy.

[0120] When the switch tube S 23 When turned off, the inductor L 22 Generates induced electromotive force, current flows from inductor L22 , through diode d 24 , resistor R 22 , for capacitor C 24 It charges and supplies power to the 12V load at the same time, and finally flows back to the negative electrode of the power regulation capacitor 300.

[0121] When the power control capacitor 300 is charged (energy is obtained from the 12V side), the current flow in the second bidirectional conversion topology 420 is:

[0122] When the switch tube S 24 When it is turned on, the current flows from the 12V power supply (capacitor C 24 ) flows out of the positive electrode and passes through the resistor R 22 、Inductor L 22 , switch tube S 24 , and then flows back to the negative electrode of the 12V power supply (ground terminal). 22 Store energy.

[0123] When the switch tube S 24 When turned off, the inductor L 22 Generates induced electromotive force, current flows from inductor L 22 flows out through diode d 23 The power regulating capacitor 300 is charged and finally flows back to the negative electrode of the 12V power supply (ground terminal).

[0124] Its control method is similar to that of the first voltage conversion module 200, which adopts a double closed-loop control method of current inner loop and voltage outer loop. The difference is that the second voltage conversion module 400 adopts four switch tubes. Specifically, the voltage reference value V ref1 The difference between the collected voltage V1 and the reference current i1* is adjusted by PI. The difference between the reference current i1 and the measured input current i1 is adjusted by PI to output the duty cycle d1 of the switch tube S1 and the duty cycle d2 of the switch tube S2. Similarly, the voltage reference value V ref2 The difference is subtracted from the collected voltage V2, and the difference is adjusted by PI to output the current reference reference i2*. The difference is subtracted from the measured input current i2, and the difference is adjusted by PI to output the duty cycle d3 of the switch tube S3 and the duty cycle d4 of the switch tube S4. It should be noted that the sum of the values d1 and d2 is 1, and the sum of the values d3 and d4 is 1. In this embodiment, V ref1 、V ref2 They are still 48V and 12V respectively; i1 represents the 48V branch current value, and i2 represents the 12V branch current value; through the above control method, the output voltage can be controlled at 48V and 12V respectively.

[0125] In the vehicle low-voltage power supply system provided by the embodiment of the present disclosure, its second voltage conversion module 400 adopts a first bidirectional conversion topology 410 and a second bidirectional conversion topology 420 connected in parallel. The first bidirectional conversion topology 410 connects the power control capacitor 300 to the first low-voltage bus 10, and the second bidirectional conversion topology 420 connects the power control capacitor 300 to the second low-voltage bus 20. Both control the direction of energy transmission based on the voltage value of the power control capacitor 300. In this way, the power control capacitor 300 can flexibly exchange energy with the two low-voltage buses, improving the system's response speed to instantaneous power demand and ensuring voltage stability.

[0126] Figure 6 This is a flow chart of a control method for a vehicle low-voltage power supply system provided by an embodiment of the present disclosure, which is applied to Figure 1 、 2 , or any one of the vehicle low-voltage power supply systems shown in 4.

[0127] The control method includes:

[0128] Step S601: Acquire the power supply mode of the vehicle power system.

[0129] The vehicle's power management system (such as the battery management system and vehicle controller) is used to obtain the power supply mode of the vehicle's power system. This involves detecting whether the high-voltage power supply is enabled, the status of the high-voltage relay, the voltage and current of the low-voltage bus, and other information to determine whether the system is in high-voltage power supply mode or not.

[0130] Step S602 : When the vehicle power system is in a high-voltage power supply mode, a power supply source is selected from the power control capacitor and the high-voltage power supply according to the energy storage state of the power control capacitor.

[0131] In high-voltage power supply mode, the power source is dynamically selected based on the energy storage state of the power-regulating capacitors. This fully leverages the high power density of the power-regulating capacitors to meet the vehicle's instantaneous power requirements, while also rationally utilizing the high energy density of the high-voltage power supply to improve the energy efficiency of the entire system. For example, when the vehicle is accelerating, the power-regulating capacitors can provide the majority of the required power, reducing the depth of discharge of the high-voltage power supply and extending its service life. In cruising conditions, the high-voltage power supply can become the primary power source, while the power-regulating capacitors are in standby or low-current charging mode, ensuring the proper distribution of system energy.

[0132] Step S603 : When the vehicle power system is not in the high-voltage power supply mode, a power supply source is selected from the power control capacitor and the low-voltage energy storage module according to the load demand level.

[0133] Selecting the power supply according to the load demand level can maximize the advantages of power control capacitors and low-voltage energy storage modules, achieve efficient energy utilization, and improve the overall energy efficiency of the system.

[0134] In this way, by dynamically allocating the power supply ratio of the power control capacitor and the high-voltage power supply in the high-voltage power supply mode, the high power density of the power control capacitor and the high energy density characteristics of the high-voltage power supply can be effectively utilized to improve the energy utilization efficiency of the entire system. For example, when the vehicle accelerates, the power control capacitor can provide most of the instantaneous power demand, reducing the discharge depth of the high-voltage power supply and extending the service life of the high-voltage power supply; under cruising conditions, the high-voltage power supply can be the dominant power supply, and the power control capacitor is in standby or low-current charging state to ensure the rational distribution of system energy. In the non-high-voltage power supply mode, the power supply is selected according to the load demand level, which can maximize the advantages of the power control capacitor and the low-voltage energy storage module, achieve efficient energy utilization, and improve the overall energy efficiency of the system.

[0135] At the same time, dynamic power supply ratio allocation and power source selection strategies can be adjusted based on the real-time system status, enhancing the system's adaptability to different operating conditions and reducing the risk of system failures due to insufficient or overloaded power. For example, when the vehicle is starting or driving at low speeds, if the high-voltage power supply is not enabled, the power-regulating capacitor can provide the necessary power support for critical loads, ensuring the normal operation of the vehicle's basic functions. If the power-regulating capacitor is low on charge, power is promptly switched to the low-voltage energy storage module, avoiding system power outages and improving system reliability.

[0136] In high-voltage power supply mode, the power-regulating capacitor absorbs most of the instantaneous power fluctuations, reducing the frequency and depth of charge and discharge of the high-voltage power supply, thereby helping to extend the cycle life of the high-voltage power supply. Furthermore, by properly controlling the charge and discharge process of the power-regulating capacitor, overcharge and over-discharge can be avoided, thereby increasing the service life of the power-regulating capacitor. In non-high-voltage power supply mode, properly selecting the power source based on the load demand level can reduce the frequent high-current charge and discharge of the low-voltage energy storage module, slowing its capacity decay and extending its service life.

[0137] Optionally, the control method further includes:

[0138] When the power of the low-voltage energy storage module is less than the set power value, the intelligent power replenishment mode is operated and the power control capacitor charges the low-voltage energy storage module.

[0139] Here, the power control capacitor is given priority to replenish power to avoid deep discharge of the small battery. The vehicle's battery management system monitors the power of the low-voltage energy storage module in real time, compares it with the set power value, and determines whether the power of the low-voltage energy storage module is lower than the set value. When the power of the low-voltage energy storage module is less than the set power value, the system automatically enters the intelligent charging mode. The solution can make full use of the high power density and fast charging and discharging characteristics of the power control capacitor to replenish power in time when the low-voltage energy storage module is low on power, thereby improving the energy utilization efficiency of the entire system and reducing energy waste. It avoids the degradation of system performance or functional limitations due to insufficient power in the low-voltage energy storage module, ensuring the normal operation of the vehicle, and also helps to balance the charge state of the power control capacitor and the low-voltage energy storage module, extending the service life of both.

[0140] Optionally, selecting a power supply from the power control capacitor and the high-voltage power supply according to the energy storage state of the power control capacitor includes:

[0141] If the energy storage state of the power control capacitor meets the instantaneous power support condition, then when the instantaneous power demand is detected, the power control capacitor is controlled to serve as the power supply;

[0142] If the energy storage state of the power control capacitor does not meet the instantaneous power support condition, the high-voltage power supply is triggered as the power supply to perform continuous power supply and charge the power control capacitor with the remaining available power.

[0143] The energy storage state (State of Charge, SOC) of the power control capacitor is used to reflect the ratio of the remaining charge in the power control capacitor to the charge when it is fully charged. In the high-voltage power supply mode, the power control capacitor management system (including voltage sensors, current sensors and temperature sensors, etc.) is used to monitor the key parameters of the power control capacitor in real time, such as voltage, current and temperature, and the SOC of the power control capacitor is calculated based on this. For example, by measuring the real-time voltage of the power control capacitor and combining it with its voltage-capacity characteristic curve, the current SOC value is estimated. Therefore, according to the SOC of the power control capacitor and the current power demand of the vehicle, a preset control strategy is used to select the power supply.

[0144] The instantaneous power support condition refers to setting a storage state threshold. When the SOC of the power control capacitor is greater than the storage state threshold, the energy state of the power control capacitor meets the instantaneous power support condition; when the SOC of the power control capacitor is less than or equal to the storage state threshold, the energy state of the power control capacitor does not meet the instantaneous power support condition. In this embodiment, the storage state threshold is 20%.

[0145] When the energy storage state of the power control capacitor meets the instantaneous power support conditions, when the instantaneous power demand is detected, the control module sends a control signal to enable the power control capacitor to supply power to the load through the second voltage conversion module; when the energy storage state of the power control capacitor does not meet the instantaneous power support conditions, the high-voltage power supply is triggered to continuously supply power to the load through the first voltage conversion module, and the remaining available power of the high-voltage power supply is used to charge the power control capacitor through the second voltage conversion module.

[0146] In this way, the power source is dynamically selected based on the energy storage state of the power control capacitor. While meeting the vehicle's instantaneous power demand, the excess power of the high-voltage power supply is rationally utilized to charge the power control capacitor. This fully leverages the high power density of the power control capacitor and the high energy density of the high-voltage power supply, improving the energy efficiency of the entire system. This avoids a single power source from shouldering excessive power output, extending the service life of the power control capacitor and the high-voltage power supply, and reducing system maintenance costs and replacement frequency.

[0147] By monitoring the energy storage status of the power control capacitor and the vehicle's power requirements, the system adjusts the power supply selection in real time, enhancing the system's adaptability to different operating conditions and reducing the risk of system failure due to insufficient or overloaded power. Furthermore, when the energy storage status of the power control capacitor does not meet the requirements, the high-voltage power supply is used to charge the power control capacitor, ensuring that the power control capacitor can function normally when needed, thereby enhancing the system's redundancy and fault tolerance.

[0148] Optionally, selecting a power supply from the power control capacitor and the low-voltage energy storage module according to the load demand level includes:

[0149] If there is a high-power load running, the power supply is determined between the power control capacitor and the low-voltage energy storage module according to the energy storage state of the power control capacitor;

[0150] If there is no high-power load running, the low-voltage energy storage module is selected as the power supply to provide continuous power supply.

[0151] Load demand levels can be detected by monitoring the operating status and power requirements of various vehicle loads in real time through the vehicle's network communication system (such as the CAN bus and LIN bus). Based on preset power thresholds, loads are divided into high-power loads (such as cooling fans, power steering, and active suspension, typically with power greater than 1kW) and low-power loads (such as lamps, sensors, and fragrances, typically with power less than 100W).

[0152] When a high-power load is detected, the power supply is determined between the power control capacitor and the low-voltage energy storage module according to the energy storage state of the power control capacitor, including: when the energy storage state of the power control capacitor is greater than the set threshold, the power control capacitor is selected as the power supply; when the energy storage state of the power control capacitor is less than or equal to the set threshold, the low-voltage energy storage module is selected as the power supply.

[0153] A threshold is set to indicate a situation where the SOC of the power control capacitor is high and the output power meets the load demand. In the embodiment of the present disclosure, the threshold is set to 20%. Here, the power supply is determined based on the SOC of the power control capacitor. If the SOC of the power control capacitor is high and the output power meets the load demand, the power control capacitor is selected as the main power supply; if the SOC of the power control capacitor is low or the output power is insufficient, the low-voltage energy storage module is selected as the main power supply, and the power control capacitor can be controlled to provide auxiliary power supply until its SOC drops to a certain threshold. When there is no high-power level load running, the low-voltage energy storage module is directly selected as the power supply to provide continuous and stable power supply for low-power level loads.

[0154] The control module generates corresponding control signals according to the above logic, and controls the charging and discharging process of the second voltage conversion module and the low-voltage energy storage module through the driving circuit to realize the switching of power supply and power distribution.

[0155] Specifically, determining the power supply source between the power control capacitor and the low-voltage energy storage module according to the energy storage state of the power control capacitor includes:

[0156] When the SOC of the power control capacitor is greater than 20%, the power control capacitor is selected as the power supply;

[0157] When the SOC of the power control capacitor is less than or equal to 20%, the low-voltage energy storage module is selected as the power supply.

[0158] This allows for optimal selection of power sources based on actual load demand, leveraging the high power density of the power-regulating capacitors and the high energy density of the low-voltage energy storage modules to improve energy efficiency and reduce energy waste. When high-power loads are in operation, the power-regulating capacitors are prioritized to provide instantaneous high power, preventing frequent high-current discharges from the low-voltage energy storage modules and extending their service life. When no high-power loads are in operation, the low-voltage energy storage modules provide stable power, ensuring system energy efficiency.

[0159] By real-time monitoring of load demand and power control capacitor energy storage status, the power supply selection is dynamically adjusted, which enhances the system's adaptability to different load conditions and reduces the risk of system failure caused by insufficient power supply or overload.

[0160] Figure 7This is a second flow chart of a control method for a vehicle low-voltage power supply system provided by an embodiment of the present disclosure, which is applied to Figure 1 、 2 , or any one of the vehicle low-voltage power supply systems shown in 4.

[0161] The control method includes:

[0162] Step S701: Obtain the power supply mode of the vehicle power system.

[0163] Step S702: When the vehicle power system is in a high-voltage power supply mode, obtain the power control capacitor SOC;

[0164] Step S703 , when the SOC of the power control capacitor is greater than 20%, and when the high frequency filter detects an instantaneous power demand, the power control capacitor is controlled to serve as a power supply;

[0165] Step S704: When the SOC of the power control capacitor is less than or equal to 20%, the high-voltage power supply is controlled to continuously supply power and the power control capacitor is charged with the remaining available power.

[0166] Step S705: When the vehicle power system is not in the high-voltage power supply mode, obtain the high-power load operation status;

[0167] Step S706, when a high-power load is running, obtaining the SOC of the power control capacitor;

[0168] Step S707: When the SOC of the power control capacitor is greater than 20%, the power control capacitor is controlled to be used as a power supply;

[0169] Step S708: When the SOC of the power control capacitor is less than or equal to 20%, or when there is no high-power load, the low-voltage energy storage module is controlled to serve as the power supply.

[0170] Using the control method provided by the embodiment of the present disclosure, it is possible to flexibly select the most appropriate power supply according to different working conditions and the energy storage state of the power control capacitor, give full play to the high power density of the power control capacitor and the high energy density advantages of the high voltage power supply and low voltage energy storage module, improve the energy utilization efficiency of the entire system, and reduce energy waste. For example, in the high voltage power supply mode and when the power control capacitor SOC is high, the power control capacitor is preferentially used to meet the instantaneous power demand, avoiding frequent high current charging and discharging of the high voltage power supply, and improving the service life of the high voltage power supply; in the non-high voltage power supply mode, the power supply of the power control capacitor and the low voltage energy storage module is reasonably allocated to ensure efficient energy utilization. By real-time monitoring of parameters such as the power supply mode, power control capacitor SOC and high power load operation status of the vehicle power system, and based on this, fast and accurate power supply switching control is performed, the adaptability and stability of the system to different working conditions are effectively enhanced. When faced with instantaneous power demand, it can respond quickly to avoid excessive system voltage fluctuations and ensure the stable operation of the vehicle electrical system. For example, when the SOC of the power control capacitor is low, it switches to the high-voltage power supply or low-voltage energy storage module for power supply in time to prevent power interruption or voltage drop caused by insufficient power of the power control capacitor, thereby improving the reliability and stability of the system.

[0171] Figure 8 2 is a schematic diagram of a control device for a vehicle low-voltage power supply system provided by an embodiment of the present disclosure.

[0172] Combine Figure 8 As shown, an embodiment of the present disclosure provides a control device 80 for a vehicle low-voltage power supply system, including a processor 800 and a memory 801. Optionally, the device 80 may also include a communication interface 802 and a bus 803. The processor 800, the communication interface 802, and the memory 801 can communicate with each other through the bus 803. The communication interface 802 can be used for information transmission. The processor 800 can call the logic instructions in the memory 801 to execute the control method for the vehicle low-voltage power supply system of the above embodiment.

[0173] In addition, the logic instructions in the memory 801 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0174] Memory 801, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of the present disclosure. Processor 800 executes the program instructions / modules stored in memory 801 to perform functional applications and data processing, thereby implementing the control method for a vehicle low-voltage power supply system in the above-mentioned embodiments.

[0175] The memory 801 may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the terminal device. Furthermore, the memory 801 may include high-speed random access memory and non-volatile memory.

[0176] An embodiment of the present disclosure provides a vehicle, comprising: a vehicle body, and the above-mentioned control device for the vehicle low-voltage power supply system. The control device for the vehicle low-voltage power supply system is installed on the vehicle body. The installation relationship described here is not limited to placement inside the vehicle body, but also includes installation connections with other components of the vehicle, including but not limited to physical connections, electrical connections or signal transmission connections, etc. It can be understood by those skilled in the art that the control device for the vehicle low-voltage power supply system can be adapted to a feasible vehicle body, thereby realizing other feasible embodiments.

[0177] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned control method for a vehicle low-voltage power supply system.

[0178] The technical solutions of the embodiments of the present disclosure may be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present disclosure. The aforementioned storage medium may be a non-transitory storage medium, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, among other media capable of storing program code.

[0179] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include plural forms. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of one or more associated listings. In addition, when used in this application, the term "comprise" and its variations "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups of these. In the absence of further restrictions, an element defined by the sentence "comprising a..." does not exclude the presence of other identical elements in the process, method or device that includes the element. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments can be referenced to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can be found in the description of the method part.

[0180] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present disclosure. The technicians will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0181] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units can be merely a logical functional division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, and can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. In addition, the functional units in the embodiments of the present disclosure may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0182] The flowcharts and block diagrams in the accompanying drawings show the possible implementation architectures, functions and operations of the systems, methods and computer program products according to the embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment or part of the code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical functions. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, which can depend on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A vehicle low-voltage power supply system, characterized in that: include: A high-voltage power supply (100), a first voltage conversion module (200), a power control capacitor (300), a second voltage conversion module (400), a low-voltage energy storage module (500), a control module (600), and a voltage-dividing load (700); The high-voltage power supply (100) is electrically connected to a first low-voltage bus (10) and a second low-voltage bus (20) via the first voltage conversion module (200), and the first voltage conversion module (200) is configured to convert the high-voltage power supply voltage into a first-level voltage and a second-level voltage; The power control capacitor (300) is bidirectionally electrically connected to the first low-voltage bus (10) and the second low-voltage bus (20) via the second voltage conversion module (400), and the second voltage conversion module (400) is configured to support bidirectional flow of energy between the power control capacitor and the two low-voltage buses; The low-voltage energy storage module (500) is electrically connected to the second low-voltage bus (20); The voltage-dividing load (700) is electrically connected to the first low-voltage bus (10) and / or the second low-voltage bus (20); The control module (600) is communicatively connected to the first voltage conversion module (200), the second voltage conversion module (400) and the voltage-dividing load, and is configured to output a control signal to dynamically select at least one of the high-voltage power supply (100), the power regulation capacitor (300) and the low-voltage energy storage module (500) as a power supply.

2. The vehicle low-voltage power supply system according to claim 1, characterized in that: The first voltage conversion module (200) includes a first buck topology (210) and a second buck topology (220) connected in series; The input end of the first buck topology (210) is connected to the output end of the high-voltage power supply (100), and the output end of the first buck topology (210) is respectively connected to the first low-voltage bus (10) and the input end of the second buck topology (220); the first buck topology (210) is configured to reduce the high-voltage power supply voltage to a first-level voltage; The output end of the second buck topology (220) is connected to the second bus voltage (20); the second buck topology (220) is configured to reduce the first level voltage to a second level voltage.

3. The vehicle low-voltage power supply system according to claim 1, characterized in that: The second voltage conversion module (400) includes a first bidirectional conversion topology (410) and a second bidirectional conversion topology (420) connected in parallel; One end of the first bidirectional conversion topology (410) is connected to a power control capacitor (300), and the other end is connected to a first low-voltage bus (10); the first bidirectional conversion topology (410) is configured to control the energy transmission direction according to the voltage value of the power control capacitor (300); One end of the second bidirectional conversion topology (420) is connected to the power control capacitor (300), and the other end is connected to the second low-voltage bus (20); the second bidirectional conversion topology (420) is configured to control the energy transmission direction according to the voltage value of the power control capacitor (300).

4. A control method for the vehicle low-voltage power supply system according to any one of claims 1 to 3, characterized in that: include: Obtain the power supply mode of the vehicle power system; When the vehicle power system is in high-voltage power supply mode, a power supply source is selected from the power control capacitor and the high-voltage power supply according to the energy storage state of the power control capacitor; When the vehicle power system is not in high-voltage power supply mode, the power supply is selected from the power control capacitor and the low-voltage energy storage module according to the load demand level.

5. The control method according to claim 4, characterized in that: The selecting of a power supply source from the power regulating capacitor and the high-voltage power supply according to the energy storage state of the power regulating capacitor includes: If the energy storage state of the power control capacitor meets the instantaneous power support condition, then when the instantaneous power demand is detected, the power control capacitor is controlled to serve as the power supply; If the energy storage state of the power control capacitor does not meet the instantaneous power support condition, the high-voltage power supply is triggered as the power supply to perform continuous power supply and charge the power control capacitor with the remaining available power.

6. The control method according to claim 4, characterized in that: The selecting of a power supply from the power control capacitor and the low-voltage energy storage module according to the load demand level includes: If there is a high-power load running, the power supply is determined between the power control capacitor and the low-voltage energy storage module according to the energy storage state of the power control capacitor; If there is no high-power load running, the low-voltage energy storage module is selected as the power supply to provide continuous power supply.

7. The control method according to claim 6, characterized in that: Determining the power supply source between the power regulating capacitor and the low-voltage energy storage module according to the energy storage state of the power regulating capacitor includes: When the energy storage state of the power control capacitor is greater than a set threshold, the power control capacitor is selected as the power supply; When the energy storage state of the power control capacitor is less than or equal to the set threshold, the low-voltage energy storage module is selected as the power supply.

8. The control method according to any one of claims 4 to 7, characterized in that: Also includes: When the power of the low-voltage energy storage module is less than the set power value, the intelligent power replenishment mode is operated and the power control capacitor charges the low-voltage energy storage module.

9. A control device for a vehicle low-voltage power supply system according to any one of claims 1 to 3, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the control method according to any one of claims 4 to 8 when running the program instructions.

10. A vehicle, characterized in that: include: Vehicle body; The control device for the vehicle low-voltage power supply system according to any one of claims 1 to 3 as described in claim 9 is installed on the vehicle body.

Images