Voltage conversion system, control method thereof, vehicle, storage medium

Abstract

The application discloses a voltage conversion system and a control method thereof, a vehicle and a storage medium. The system comprises at least two voltage conversion branches, wherein a positive input end of each voltage conversion branch is connected to a positive direct-current input bus, a negative input end of each voltage conversion branch is connected to a negative direct-current input bus, a positive output end of each voltage conversion branch is connected to a positive direct-current output bus, and a negative output end of each voltage conversion branch is connected to a negative direct-current output bus; and a digital signal processor is connected to control ends of corresponding transistors in each voltage conversion branch and is used for controlling the at least two voltage conversion branches to perform voltage step-down conversion on a first voltage to obtain a second voltage. The application solves the technical problem of low stability of voltage step-down conversion in the related art.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to a voltage conversion system and its control method, a vehicle, and a storage medium. Background Technology

[0002] In the current field of intelligent connected vehicles and new energy vehicles, the stability of the low-voltage power supply network is directly related to vehicle driving safety. Current low-voltage power supply architectures typically employ a single DC-DC converter to convert high-voltage battery energy into low-voltage energy to power safety loads such as steer-by-wire, brake-by-wire, and autonomous driving perception systems. Some models use a dual DC-DC converter cold backup solution, which doubles the cost and space required; the static leakage current of the backup module exacerbates the thermal management burden; output voltage deviations cause circulating currents, causing one module to become a load, resulting in energy waste and overheating failure, leading to low stability in voltage step-down conversion within the vehicle.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This application provides a voltage conversion system and its control method, a vehicle, and a storage medium to at least solve the technical problem of low stability in voltage step-down conversion in vehicles in related technologies.

[0005] According to one aspect of the embodiments of this application, a voltage conversion system is provided, comprising: at least two voltage conversion branches, wherein the positive input terminal of each voltage conversion branch is connected to a positive DC input bus, the negative input terminal of each voltage conversion branch is connected to a negative DC input bus, the positive output terminal of each voltage conversion branch is connected to a positive DC output bus, and the negative output terminal of each voltage conversion branch is connected to a negative DC output bus; a digital signal processor, connected to the control terminal of a corresponding transistor in each voltage conversion branch, for controlling the at least two voltage conversion branches to perform voltage step-down conversion on a first voltage to obtain a second voltage, wherein the first voltage represents the voltage between the positive DC input bus and the negative DC input bus, and the second voltage represents the voltage between the positive DC output bus and the negative DC output bus.

[0006] In this embodiment, each voltage conversion branch includes: a voltage buck converter, the positive input terminal of which is connected to the positive input terminal of each voltage conversion branch, the negative input terminal of which is connected to the negative input terminal of each voltage conversion branch, and a corresponding transistor in the voltage buck converter being used to respond to a target pulse width modulation signal sent by a digital signal processor to perform voltage bucking processing on the first voltage; and a filter circuit, the positive input terminal of which is connected to the positive output terminal of the voltage buck converter, the negative input terminal of which is connected to the negative output terminal of the voltage buck converter, and the negative output terminal of which is connected to... A filter circuit is connected to the negative output terminal of each voltage conversion branch to perform current filtering. A switching unit is connected to the positive output terminal of the filter circuit and to the positive output terminal of each voltage conversion branch. The switching unit is used to turn on or off in response to on / off control commands sent by the digital signal processor. When the switching unit is in the on state, the positive output terminal of the filter circuit is connected to the positive output terminal of each voltage conversion branch. When the switching unit is in the off state, the positive output terminal of the filter circuit is bidirectionally blocked from the positive output terminal of each voltage conversion branch.

[0007] In this embodiment, the switching unit includes: a first transistor, the source of which is connected to the input terminal of the switching unit, and the gate of which is connected to a digital signal processor; and a second transistor, the drain of which is connected to the drain of the first transistor, the source of which is connected to the output terminal of the switching unit, and the gate of which is connected to the digital signal processor; wherein the digital signal processor is further configured to control the on / off state of the switching unit by controlling the on / off state of the first transistor and the second transistor.

[0008] According to another aspect of the embodiments of this application, a control method for a voltage conversion system is also provided, applied to the voltage conversion system described above. The method includes: acquiring current sampling values ​​corresponding to the positive output terminal of each voltage conversion branch in at least two voltage conversion branches; generating a target pulse width modulation signal based on the current sampling values ​​corresponding to the positive output terminal of each voltage conversion branch; and controlling the on / off state of the corresponding transistor in the voltage buck converter in each voltage conversion branch based on the target pulse width modulation signal, so as to control at least two voltage conversion branches to perform voltage buck conversion on a first voltage to obtain a second voltage.

[0009] In this embodiment, generating a target pulse width modulation signal based on the current sampling value corresponding to the positive output terminal of each voltage conversion branch includes: determining a first current sampling value corresponding to the positive output terminal of a first voltage conversion branch and a second current sampling value corresponding to the positive output terminal of a second voltage conversion branch other than the first voltage conversion branch; determining a reference voltage value corresponding to each voltage conversion branch based on the first current sampling value and the second current sampling value; and generating a target pulse width modulation signal based on the reference voltage value corresponding to each voltage conversion branch.

[0010] In this embodiment of the application, determining the reference voltage value corresponding to each voltage conversion branch based on the first current sampling value and the second current sampling value includes: obtaining the desired voltage value corresponding to the positive DC output bus; determining the reference voltage value corresponding to the first voltage conversion branch based on the desired voltage value; and determining the reference voltage value corresponding to the second voltage conversion branch based on the desired voltage value, the first current sampling value, and the second current sampling value.

[0011] In this embodiment of the application, determining the reference voltage value corresponding to the second voltage conversion branch based on the desired voltage value, the first current sample value, and the second current sample value includes: determining the average current value of the first current sample value and the second current sample value; determining the current difference between the average current value and the second current sample value; determining the target product of the proportional control coefficient and the current difference; and determining the reference voltage value corresponding to the second voltage conversion branch based on the desired voltage value and the target product.

[0012] In this embodiment of the application, the method further includes: acquiring operating status data corresponding to each voltage conversion branch, wherein the operating status data includes at least one of the following: temperature parameters, current parameters, and voltage parameters; determining whether there is an abnormal operating status branch based on the operating status data; generating a corresponding on / off control command in response to the existence of an abnormal operating status branch; and controlling the switching unit in the abnormal operating status branch to be in the off state based on the on / off control command.

[0013] According to another aspect of the embodiments of this application, a vehicle is also provided, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of this application when it runs.

[0014] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0015] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0016] According to another aspect of the embodiments of this application, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program, which, when executed by a processor, implements the methods in various embodiments of this application.

[0017] According to another aspect of the embodiments of this application, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of this application.

[0018] In this embodiment, a voltage conversion system includes: at least two voltage conversion branches, wherein the positive input terminal of each voltage conversion branch is connected to a positive DC input bus, the negative input terminal of each voltage conversion branch is connected to a negative DC input bus, the positive output terminal of each voltage conversion branch is connected to a positive DC output bus, and the negative output terminal of each voltage conversion branch is connected to a negative DC output bus; a digital signal processor is connected to the control terminal of the corresponding transistor in each voltage conversion branch, and is used to control the at least two voltage conversion branches to perform voltage step-down conversion on a first voltage to obtain a second voltage, wherein the first voltage represents the voltage between the positive DC input bus and the negative DC input bus, and the second voltage represents the voltage between the positive DC output bus and the negative DC output bus. This application achieves high stability and high reliability of the voltage conversion system by constructing a multi-branch parallel architecture and centralized digital control logic. By employing at least two voltage conversion branches connected in parallel to the common input and output buses, a physical redundancy foundation is provided in the topology. This eliminates reliance on a single power link, allowing any branch fault to be compensated by the others, thus avoiding power outages caused by single-point faults. A digital signal processor (DSP) is introduced to uniformly manage the control terminals of the transistors in each branch, enabling the DSP to acquire global status data in real time and execute complex control algorithms. Through accurate control of the buck conversion process in each branch, the DSP achieves active current sharing across multiple paths, eliminating circulating current losses and uneven thermal stress caused by component differences. It can also respond promptly to load surges or internal faults, dynamically adjusting the output power of each branch. This synergistic mechanism of hardware redundancy and intelligent software control ensures that the output bus voltage remains highly stable even when the input voltage fluctuates, the load changes abruptly, or the performance of individual modules degrades. This effectively solves the technical problems of low voltage regulation accuracy, slow dynamic response, and poor stability in traditional single-path or simple parallel schemes, meeting the high power quality requirements of critical vehicle loads and addressing the low stability of voltage buck conversion in vehicles. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a schematic diagram of a voltage conversion system according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of an optional dual-path voltage conversion system according to an embodiment of the present invention;

[0022] Figure 3 This is a flowchart of a control method for a voltage conversion system according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the control process of an optional voltage conversion system according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the control process of an optional voltage conversion system according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the control process of another optional voltage conversion system according to an embodiment of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] According to an embodiment of this application, a voltage conversion system is provided. Figure 1 This is a schematic diagram of a voltage conversion system according to this application, such as... Figure 1 As shown, the system includes at least two voltage conversion branches 102 and a digital signal processor 104.

[0029] Among them, there are at least two voltage conversion branches 102, wherein the positive input terminal of each voltage conversion branch is connected to the positive DC input bus A+, the negative input terminal of each voltage conversion branch is connected to the negative DC input bus A-, the positive output terminal of each voltage conversion branch is connected to the positive DC output bus B+, and the negative output terminal of each voltage conversion branch is connected to the negative DC output bus B-.

[0030] The aforementioned voltage conversion branch refers to the power conversion unit in a voltage conversion system. Each voltage conversion branch contains a buck converter, a filter circuit, and a switching unit. The buck converter receives the input voltage and steps it down. The transistors inside the buck converter can respond to control signals to adjust their conduction state. The filter circuit is connected to the output of the buck converter to filter the output current and smooth voltage fluctuations. The switching unit can be connected between the filter circuit and the output bus and is controlled by a digital signal processor to turn on or off, thereby achieving physical isolation or connection of the branch output, preventing current backflow, and ensuring electrical safety during master-slave switching or fault isolation.

[0031] The digital signal processor 104 is connected to the control terminal of the corresponding transistor in each voltage conversion branch, and is used to control at least two voltage conversion branches to perform voltage step-down conversion on the first voltage to obtain the second voltage. The first voltage is used to represent the voltage between the positive DC input bus and the negative DC input bus, and the second voltage is used to represent the voltage between the positive DC output bus and the negative DC output bus.

[0032] The aforementioned digital signal processor can be a microcontroller or dedicated chip used to control the entire dual-redundant DC-DC converter system. It can collect operating status data such as current, voltage, and temperature from each voltage conversion branch, and execute digital active current sharing algorithms and fault diagnosis logic. The digital signal processor is responsible for generating target pulse width modulation signals to control the switching of power transistors, dynamically adjusting the reference voltage of each branch based on current sampling values ​​to achieve load balancing, and rapidly generating on / off control commands to drive the switching unit to disconnect the faulty branch when abnormal conditions such as overvoltage, overcurrent, or overtemperature are detected, thus achieving accurate and timely fault isolation and redundancy switching.

[0033] The aforementioned first voltage can refer to the original input voltage provided by the vehicle's high-voltage power battery, specifically the potential difference between the positive and negative DC input bus. In vehicle applications, the first voltage can be in the high-voltage range of 200V to 800V, and after being processed by a voltage buck converter, it is converted into low-voltage electrical energy.

[0034] The aforementioned second voltage refers to the low-voltage stable electrical energy output after being stepped down by a voltage converter, specifically manifested as the potential difference between the positive and negative DC output buses. This second voltage can be 12V or other standard low-voltage vehicle network voltage, used to power the vehicle controller, drive-by-wire chassis system, autonomous driving sensing module, and onboard electrical equipment. The stability and accuracy of this second voltage, which supplies the low-voltage loads of the vehicle, directly affect the safe operation of the vehicle system.

[0035] In one optional embodiment, the voltage conversion system adopts a single-core dual-drive architecture, consisting of at least two independent voltage conversion branches and a shared digital signal processor. Each voltage conversion branch has independent input / output interfaces: the positive and negative input terminals are connected in parallel to the positive and negative DC input buses of the high-voltage power battery, respectively, to receive the high-voltage first voltage; the positive and negative output terminals converge to the positive and negative terminals of the low-voltage DC output bus, outputting a stable second voltage. The digital signal processor, acting as the system controller, is directly connected to the control terminals of the power transistors inside each branch via control lines. It collects current, voltage, and temperature data of each voltage conversion branch in real time, executes digital active current sharing algorithms and fault diagnosis logic, and dynamically generates target pulse width modulation signals and on / off control commands. By accurately adjusting the switching duty cycle of each branch transistor, at least two voltage conversion branches can be operated in alternating parallel configurations and load balancing can be achieved. When a fault is detected, the digital signal processor can quickly drive the switching unit to disconnect the faulty branch, achieving accurate and timely isolation.

[0036] Through the above configuration, high-precision digital active current sharing is achieved by centrally controlling at least two independent voltage conversion branches via a digital signal processor. This keeps current deviation within a small range, effectively eliminating circulating current losses in parallel schemes, improving the overall efficiency of the voltage conversion system, and reducing thermal stress. The independent branch structure combined with the rapid isolation mechanism controlled by the digital signal processor enables redundancy backup. When a voltage conversion branch fails, other voltage conversion branches can promptly take over the load, ensuring zero power interruption for safety systems such as the wire-controlled chassis. The modular design simplifies the hardware architecture, avoids the use of external distribution boxes, and improves power density and reliability.

[0037] In this embodiment, a voltage conversion system includes: at least two voltage conversion branches, wherein the positive input terminal of each voltage conversion branch is connected to a positive DC input bus, the negative input terminal of each voltage conversion branch is connected to a negative DC input bus, the positive output terminal of each voltage conversion branch is connected to a positive DC output bus, and the negative output terminal of each voltage conversion branch is connected to a negative DC output bus; a digital signal processor is connected to the control terminal of the corresponding transistor in each voltage conversion branch, and is used to control the at least two voltage conversion branches to perform voltage step-down conversion on a first voltage to obtain a second voltage, wherein the first voltage represents the voltage between the positive DC input bus and the negative DC input bus, and the second voltage represents the voltage between the positive DC output bus and the negative DC output bus. This application achieves high stability and high reliability of the voltage conversion system by constructing a multi-branch parallel architecture and centralized digital control logic. By employing at least two voltage conversion branches connected in parallel to the common input and output buses, a physical redundancy foundation is provided in the topology. This eliminates reliance on a single power link, allowing any branch fault to be compensated by the others, thus avoiding power outages caused by single-point faults. A digital signal processor (DSP) is introduced to uniformly manage the control terminals of the transistors in each branch, enabling the DSP to acquire global status data in real time and execute complex control algorithms. Through accurate control of the buck conversion process in each branch, the DSP achieves active current sharing across multiple paths, eliminating circulating current losses and uneven thermal stress caused by component differences. It can also respond promptly to load surges or internal faults, dynamically adjusting the output power of each branch. This synergistic mechanism of hardware redundancy and intelligent software control ensures that the output bus voltage remains highly stable even when the input voltage fluctuates, the load changes abruptly, or the performance of individual modules degrades. This effectively solves the technical problems of low voltage regulation accuracy, slow dynamic response, and poor stability in traditional single-path or simple parallel schemes, meeting the high power quality requirements of critical vehicle loads and addressing the low stability of voltage buck conversion in vehicles.

[0038] In this embodiment, each voltage conversion branch includes: a voltage buck converter, the positive input terminal of which is connected to the positive input terminal of each voltage conversion branch, the negative input terminal of which is connected to the negative input terminal of each voltage conversion branch, and a corresponding transistor in the voltage buck converter being used to respond to a target pulse width modulation signal sent by a digital signal processor to perform voltage bucking processing on the first voltage; and a filter circuit, the positive input terminal of which is connected to the positive output terminal of the voltage buck converter, the negative input terminal of which is connected to the negative output terminal of the voltage buck converter, and the negative output terminal of which is connected to... A filter circuit is connected to the negative output terminal of each voltage conversion branch to perform current filtering. A switching unit is connected to the positive output terminal of the filter circuit and to the positive output terminal of each voltage conversion branch. The switching unit is used to turn on or off in response to on / off control commands sent by the digital signal processor. When the switching unit is in the on state, the positive output terminal of the filter circuit is connected to the positive output terminal of each voltage conversion branch. When the switching unit is in the off state, the positive output terminal of the filter circuit is bidirectionally blocked from the positive output terminal of each voltage conversion branch.

[0039] The aforementioned voltage buck converter can refer to a power conversion module located within each voltage conversion branch. Its positive input terminal is connected to the positive terminal of the DC input bus, and its negative input terminal is connected to the negative terminal of the DC input bus, responsible for receiving the initial voltage from the high-voltage power battery. This voltage buck converter internally contains switching devices such as power transistors. The gates or control terminals of these devices are connected to a digital signal processor (DSP) to receive the target pulse width modulation (PWM) signal. The working principle of the voltage buck converter is to chop the input high-voltage DC power in response to the high-frequency switching signal issued by the DSP, converting the high-voltage DC power into low-voltage pulsed DC power, thus facilitating voltage level conversion and energy transfer.

[0040] The aforementioned filter circuit can refer to a passive or semi-active network connected in series between the output terminal of the buck converter and the branch output bus. The positive input terminal is connected to the positive output terminal of the buck converter, the negative input terminal is connected to the negative output terminal, and the negative output terminal is connected to the negative output terminal of the entire voltage conversion branch. The main function of this filter circuit is to smooth the pulsating DC output of the buck converter. It filters out high-frequency switching noise and current ripple through energy storage components such as inductors and capacitors, thereby outputting a more stable DC voltage and current. This provides high-quality power to the subsequent switching units and loads, ensuring output voltage stability and reducing electromagnetic interference.

[0041] The aforementioned switching unit can refer to a bidirectional blocking control device connected in series between the positive output terminal of the filter circuit and the positive output terminal of the voltage conversion branch. The input terminal of the switching unit is connected to the positive output terminal of the filter circuit, and the output terminal is connected to the positive output bus of the branch. The switching unit can consist of two transistors connected back-to-back, with their gates controlled by a digital signal processor to receive on / off control commands. Under normal operation, the switching unit is in the on state, allowing the filtered current to flow to the load; under fault or isolation mode, the switching unit is in the off state, bidirectionally blocking the electrical connection between the positive output terminal of the filter circuit and the positive output terminal of the branch, preventing abnormal voltage from the faulty branch from flowing back to the common bus, thereby achieving electrical isolation and fault-safe disconnection.

[0042] In one optional embodiment, each voltage conversion branch consists of a buck converter, a filter circuit, and a switching unit connected in series. The buck converter is directly connected in parallel to the DC input bus. Its internal transistors receive the target pulse width modulation signal from the digital signal processor, converting the high-voltage voltage into low-voltage pulsed DC. The filter circuit is connected in series at the converter output to filter out high-frequency switching noise, outputting smooth DC. Its negative terminal is connected to the negative output terminal of the branch to form a loop. The switching unit is connected in series between the positive terminal of the filter circuit and the positive output terminal of the branch, and is driven by the digital signal processor through on / off control commands. During normal operation, the switching unit is on, allowing filtered power to flow to the common bus; in fault or isolation mode, the switching unit is off, using its internal bidirectional blocking structure to cut off the current path. This structure ensures that each voltage conversion branch has independent power conversion, filtering, and electrical isolation capabilities, and all voltage conversion branches converge to the common DC output bus, achieving efficient power collection and distribution.

[0043] The above configuration achieves modular and physically isolated redundant power supply. By introducing switching units, the voltage conversion system can promptly disconnect abnormal branches upon detecting a fault, preventing fault current or voltage backflow from affecting other normal branches and loads, thus achieving hardware-level fault isolation. Independent filtering and conversion structures ensure the relative independence of each branch's operation. Combined with digital control, parallel circulating currents can be effectively suppressed, improving the efficiency of the voltage conversion system. This architecture simplifies external power distribution logic and enhances the survivability of the voltage conversion system under single-point fault conditions, ensuring that loads such as drive-by-wire chassis can still receive a stable and continuous power supply even when some modules fail, thereby improving the safety and reliability of the entire vehicle's electrical system.

[0044] In this embodiment, the switching unit includes: a first transistor, the source of which is connected to the input terminal of the switching unit, and the gate of which is connected to a digital signal processor; and a second transistor, the drain of which is connected to the drain of the first transistor, the source of which is connected to the output terminal of the switching unit, and the gate of which is connected to the digital signal processor; wherein the digital signal processor is further configured to control the on / off state of the switching unit by controlling the on / off state of the first transistor and the second transistor.

[0045] The aforementioned first transistor can refer to a power switching device connected in series at the front end of the input path of the switching unit. The source of the first transistor is connected to the input terminal of the switching unit, i.e., the positive output terminal of the filter circuit, the drain is connected to the drain of the second transistor, and the gate is connected to the digital signal processor. The first transistor can be an N-channel or P-channel metal-oxide-semiconductor field-effect transistor. Its main function is to allow current to flow from the input terminal to the load terminal in the on state, and to work with the second transistor to block current in the off state. The digital signal processor regulates the on and off states of the first transistor by controlling the gate voltage of the first transistor, thereby participating in the control logic of the entire switching unit for unidirectional or bidirectional current switching, ensuring smooth current flow during normal operation, and assisting in cutting off the current path when isolation is required.

[0046] The aforementioned second transistor can refer to a power switching device connected in series at the end of the output path of the switching unit. Its drain is connected to the drain of the first transistor, forming a back-to-back structure. Its source is connected to the output terminal of the switching unit, i.e., the positive output terminal of the voltage conversion branch, and its gate is connected to the digital signal processor. This second transistor and the first transistor form a bidirectional blocking structure in series. When both the first and second transistors are in the off state, the opposite orientation of the body diodes of the transistors achieves high-impedance bidirectional electrical isolation between the input and output terminals of the switching unit. The digital signal processor independently controls the gate state of the second transistor to ensure reliable blocking of any potential reverse current from the output or input terminals during fault isolation or system shutdown, thereby protecting the downstream load or front-end circuit from abnormal voltage or current.

[0047] In one optional embodiment, the switching unit adopts a back-to-back series structure, consisting of a first transistor and a second transistor. The source of the first transistor is connected to the input terminal of the switching unit, i.e., the positive output terminal of the filter circuit; its gate is connected to the digital signal processor (DSP) to receive control signals. The source of the second transistor is connected to the output terminal of the switching unit, i.e., the positive output terminal of the voltage conversion branch; the drain of the second transistor is connected to the drain of the first transistor, forming a drain-to-drain series topology. The gates of both transistors are independently connected to the DSP. In the normal conduction state, the DSP simultaneously drives the first and second transistors to conduct, and current flows from the filter circuit through the first transistor to the second transistor, outputting to the common bus. When isolation is required, the DSP outputs a gate-cutting drive signal to turn off the gates of both transistors, causing the first and second transistors to turn off. Since the drains of the two transistors are connected and their sources face the input and output terminals respectively, when both are turned off, the opposite orientation of the transistor's body diodes achieves bidirectional electrical blocking from the input terminal to the output terminal and from the output terminal to the input terminal, cutting off the current path.

[0048] The above configuration achieves highly reliable bidirectional fault isolation. The back-to-back series structure utilizes the opposite orientation of the body diodes of the two transistors, forming a high-impedance bidirectional isolation barrier in the off state. This effectively prevents backflow of common bus voltage into the faulty branch during a single-path fault, avoiding fault escalation. Controlled by a digital signal processor, the system has a fast response speed and can promptly complete physical disconnection. This ensures that in the event of severe faults such as overvoltage or overcurrent, the faulty branch can be quickly and safely isolated from the system, guaranteeing the power supply safety of other normal branches and downstream loads, thus improving the overall functional safety of the voltage conversion system.

[0049] Figure 2 This is a schematic diagram of an optional dual-path voltage conversion system according to an embodiment of the present invention, as shown below. Figure 2As shown, the voltage conversion system includes: two voltage conversion branches, each including a voltage buck converter 1022, the positive input terminal of which is connected to the positive input terminal A+ of each voltage conversion branch, and the negative input terminal of which is connected to the negative input terminal A- of each voltage conversion branch; a filter circuit 1024, the positive input terminal of which is connected to the positive output terminal of the voltage buck converter, the negative input terminal of which is connected to the negative output terminal of the voltage buck converter, and the negative output terminal of which is connected to the negative output terminal B- of each voltage conversion branch; and a switching unit 1026, the input terminal of which is connected to the positive output terminal of the filter circuit, and the output terminal of which is connected to the positive output terminal B+ of each voltage conversion branch. A digital signal processor 104 is connected to the control terminal of the corresponding transistor in each voltage conversion branch, and is used to control at least two voltage conversion branches to perform voltage buck conversion on the first voltage to obtain a second voltage.

[0050] According to another aspect of the embodiments of this application, a control method for a voltage conversion system is also provided, applied to the voltage conversion system described above. It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0051] Figure 3 This is a flowchart of a control method for a voltage conversion system according to an embodiment of this application, such as... Figure 3 As shown, the method includes the following steps:

[0052] Step S302: Collect the current sampling value corresponding to the positive output terminal of each voltage conversion branch in at least two voltage conversion branches.

[0053] The aforementioned current sampling values ​​refer to the actual current values ​​flowing out of the positive output terminal of each voltage conversion branch, collected in real time by a high-precision analog-to-digital converter, reflecting the current load sharing of that branch. In a dual-redundant system, the digital signal processor acquires the first current sampling value of the first voltage conversion branch and the second current sampling value of the second voltage conversion branch, respectively, as the basic input parameters for implementing the digital active current sharing algorithm. By calculating the deviation between the current sampling values ​​of each branch and the target current sharing current, the control strategy is dynamically adjusted to ensure that the two or more DC-DC converters can equally bear the total load current, avoiding single-path overload or circulating current loss, thereby improving the overall efficiency and stability of the voltage conversion system.

[0054] Step S304: Generate a target pulse width modulation signal based on the current sampling value corresponding to the positive output terminal of each voltage conversion branch.

[0055] The aforementioned target pulse width modulation (PWM) signal can refer to a control waveform generated by a digital signal processor based on current sampling values ​​and current sharing algorithm calculations. This waveform is used to control the on-time and off-time ratio of the power transistors in a buck converter. The target PWM signal adjusts the pulse width to change the transistor's duty cycle, thereby accurately controlling the output voltage and current of the buck converter. In current sharing control mode, the target PWM signal for the main branch is generated by stabilizing the output voltage using a voltage loop, while the target PWM signal for the secondary branch is fine-tuned based on the current difference to follow the main branch or maintain a set current ratio. The target PWM signal can drive the gate of the power transistor, achieving closed-loop accurate control of the voltage conversion process from the first voltage to the second voltage, ensuring a rapid system response and stable low-voltage output during load jumps or fault switching.

[0056] Step S306: Based on the target pulse width modulation signal, control the on / off state of the corresponding transistor in the voltage buck converter in each voltage conversion branch, so as to control at least two voltage conversion branches to perform voltage buck conversion on the first voltage to obtain the second voltage.

[0057] In one optional embodiment, a high-precision current sensor can synchronously acquire the actual current sampling values ​​at the positive output terminal of each voltage conversion branch. These current sampling values ​​reflect the current load sharing of each branch. Then, a digital signal processor (DSP) uses this current data, combined with a preset current sharing algorithm, such as the average current method or the master-slave adaptive method, to calculate the voltage reference value required for each DC voltage conversion. Specifically, the current deviations of each branch can be compared, and the voltage setpoint can be dynamically adjusted to generate the corresponding target pulse width modulation (PWM) signal. Finally, the generated target PWM signal can be sent to the power transistor control terminal in each voltage conversion branch to accurately adjust the transistor's on and off duty cycles. Through this high-frequency switching control, the high-voltage first voltage is stepped down, and a stable low-voltage second voltage is output. The entire process is coordinated by the DSP to ensure the collaborative operation of multiple converters.

[0058] The above settings enable high-precision digital active current sharing and efficient, stable system operation. By acquiring current in real time and dynamically adjusting the pulse width modulation signal, circulating current caused by differences in device parameters or line impedance can be eliminated, keeping the current differences between different channels within a small range. This improves overall system efficiency and reduces thermal stress on power devices. Closed-loop control based on current sampling enhances the dynamic response to load changes, ensuring rapid recovery of current sharing during load jumps. This fully digital control method improves system flexibility and scalability, achieving accurate control of multiple parallel circuits without complex analog circuits, providing a solid foundation for the subsequent introduction of fault diagnosis and intelligent management functions.

[0059] In this embodiment, generating a target pulse width modulation signal based on the current sampling value corresponding to the positive output terminal of each voltage conversion branch includes: determining a first current sampling value corresponding to the positive output terminal of a first voltage conversion branch and a second current sampling value corresponding to the positive output terminal of a second voltage conversion branch other than the first voltage conversion branch; determining a reference voltage value corresponding to each voltage conversion branch based on the first current sampling value and the second current sampling value; and generating a target pulse width modulation signal based on the reference voltage value corresponding to each voltage conversion branch.

[0060] The aforementioned first current sample value refers to the actual load current value flowing out of the positive output terminal of the first voltage conversion branch, which is collected in real time by a high-precision current sensor. This reflects the magnitude of the current supplied by the first voltage conversion branch to the common DC output bus, serving as the basis for the digital signal processor to determine the system load status and perform current sharing control. In the active current sharing algorithm, the first current sample value can be used to calculate the average current of each branch and as a reference for main circuit voltage loop adjustment, ensuring the stability of the output voltage and the accuracy of current distribution.

[0061] The aforementioned second current sampling value refers to the actual load current value flowing out of the positive output terminal of the second voltage conversion branch, which is collected in real time by a high-precision current sensor. It reflects the magnitude of the load current currently shared by the DC-DC converter and, together with the first current sampling value, constitutes the monitoring basis for the total output current of the system. In the current sharing control strategy, the second current sampling value is compared with the average current or the first current sampling value to calculate the current deviation. Then, by adjusting the reference voltage value of the second voltage conversion branch, the output of the second voltage conversion branch is fine-tuned, ensuring that the current in the first voltage conversion branch is balanced with that of other conversion branches, thereby eliminating circulating current and achieving efficient power sharing.

[0062] In one optional embodiment, the digital signal processor synchronously acquires the positive output current of the first and second voltage conversion branches via a high-precision analog-to-digital converter, obtaining a first current sample value and a second current sample value. Next, a reference voltage generation logic is assigned according to the master-slave roles: for the first voltage conversion branch, the reference voltage value is primarily based on the system's desired output voltage, calculated using a voltage loop proportional-integral-derivative control algorithm to stabilize the common bus voltage; for the second voltage conversion branch, the reference voltage value is based on the desired output voltage, but also incorporates the deviation information between the first and second current sample values. By calculating the current difference and adding an adjustment amount, its voltage setpoint is dynamically corrected. Finally, the reference voltage values ​​of each branch are sent to their respective pulse width modulation generators to generate target pulse width modulation signals with different duty cycles, driving the power switches of their respective branches. This maintains a stable system output voltage and automatically adjusts the output power of the second branch, achieving a balanced distribution of the two currents.

[0063] The above settings achieve high-precision digital active current sharing, effectively eliminating parallel circulating current. By introducing current sampling feedback and independently adjusting the slave reference voltage, it can compensate in real time for current unevenness caused by differences in device parameters, line impedance imbalance, or temperature drift, ensuring that the two DC-DC converters share the load according to the set ratio. This control method has a faster response speed and higher control precision, reduces circulating current losses under light loads, and improves the overall system efficiency. This strategy does not require an additional current sharing control chip; it can be implemented using the software algorithm of the main control digital signal processor, simplifying hardware circuit design, reducing system cost and size, improving the integration and reliability of the vehicle power system, and providing a stable operating foundation for subsequent fault redundancy switching.

[0064] In this embodiment of the application, determining the reference voltage value corresponding to each voltage conversion branch based on the first current sampling value and the second current sampling value includes: obtaining the desired voltage value corresponding to the positive DC output bus; determining the reference voltage value corresponding to the first voltage conversion branch based on the desired voltage value; and determining the reference voltage value corresponding to the second voltage conversion branch based on the desired voltage value, the first current sampling value, and the second current sampling value.

[0065] The aforementioned desired voltage value refers to the target regulated voltage value set by the system on the positive DC output bus, i.e., the standard output voltage required by low-voltage loads. The desired voltage value can be determined by the vehicle controller or power management strategy based on the battery state of charge and load requirements, serving as the set input in the voltage regulation closed-loop system. The digital signal processor adjusts the output power of the first voltage conversion branch by comparing the deviation between the actual output voltage and the desired voltage value, thereby ensuring that the common bus voltage remains stable at the rated level and preventing damage to onboard electronic equipment from overvoltage or undervoltage.

[0066] The reference voltage value corresponding to the first voltage conversion branch mentioned above can refer to the voltage control setpoint generated by the digital signal processor for the first voltage conversion branch. The reference voltage value corresponding to the first voltage conversion branch is mainly calculated based on the desired voltage value using a voltage loop proportional-integral-derivative control algorithm, and is used to guide the voltage stability of the entire system. The master branch adjusts its output power to make the actual output voltage track this reference voltage value as closely as possible, thereby maintaining a constant voltage on the common bus and providing a stable voltage reference for the current sharing control of the slave branches.

[0067] The reference voltage value corresponding to the second voltage conversion branch mentioned above can refer to the dynamic voltage control setpoint generated by the digital signal processor for the second voltage conversion branch. The reference voltage value corresponding to the second voltage conversion branch is based on the desired voltage value and also incorporates the current sharing deviation information of the first and second current sampling values. By calculating the difference between the two currents, the reference voltage of the second branch is fine-tuned. For example, if the slave current is too small, the slave reference voltage is slightly increased to increase the output, thereby guiding the slave to automatically share the corresponding proportion of the load current, achieving accurate active current sharing between the two DC-DC converters, and eliminating circulating current phenomena caused by differences in device parameters.

[0068] In one optional embodiment, the desired voltage value of the positive DC output bus can be obtained, which can be determined by the vehicle's low-voltage power grid standard and load requirements. For the first voltage conversion branch, the reference voltage value is calculated based on the desired voltage value through voltage outer loop proportional-integral-derivative control, aiming to stabilize the bus voltage and serve as a system reference. For the second voltage conversion branch, the reference voltage value can be determined as follows: obtain the first current sampling value and the second current sampling value, calculate the mean and difference of the two currents, and then generate a current sharing correction; subsequently, superimpose this current sharing correction onto the desired voltage value to form the reference voltage value of the second voltage conversion branch, indicating that the voltage setpoint of the slave circuit is dynamically adjusted according to the real-time current balance state. If the slave circuit current is too small, the reference voltage is raised to increase the output; if it is too large, the reference voltage is lowered. The reference voltages of the two branches respectively enter their respective pulse width modulation stages to generate drive signals.

[0069] Through the above settings, high-precision digital active current sharing and voltage stabilization decoupled control are achieved. By having the main unit independently handle voltage regulation and the slave circuit follow current balancing, severe circulating current problems caused by minor voltage differences in parallel power supplies are avoided. This control strategy allows the two DC voltage converters to evenly distribute the load current, keeping current imbalance within a small range, thereby improving overall system efficiency and reducing thermal stress and losses in power devices. Since the dynamic adjustment of the reference voltage is based on real-time sampling, it has strong adaptability to load fluctuations and device parameter drift, ensuring efficient power conversion across a wide load range and providing stable, efficient, and low-loss power support for vehicle loads.

[0070] In this embodiment of the application, determining the reference voltage value corresponding to the second voltage conversion branch based on the desired voltage value, the first current sample value, and the second current sample value includes: determining the average current value of the first current sample value and the second current sample value; determining the current difference between the average current value and the second current sample value; determining the target product of the proportional control coefficient and the current difference; and determining the reference voltage value corresponding to the second voltage conversion branch based on the desired voltage value and the target product.

[0071] The aforementioned current difference refers to the deviation between the second current sample value and the average of the first and second current sample values. It reflects the degree of imbalance between the current carried by the second voltage conversion branch and the average load current of the system, serving as an error signal in the digital active current sharing algorithm. When the current in the second branch is less than the average current, the current difference indicates that the output of the slave circuit needs to be increased; when the current in the second branch is greater than the average current, the current difference indicates that the output of the slave circuit needs to be reduced. By monitoring the current difference, the load distribution between the two power modules can be perceived in real time, providing an accurate basis for subsequent voltage fine-tuning, thereby eliminating circulating currents caused by differences in device parameters or line impedance.

[0072] The aforementioned proportional control coefficient refers to the gain parameter used to convert the current difference into a voltage regulation value. It can be tuned based on the power module's transmission characteristics, loop response speed, and stability requirements. This proportional control coefficient reflects the sensitivity of the current deviation to the adjustment of the reference voltage in the second voltage conversion branch, i.e., the adjustment range of the reference voltage corresponding to a unit current difference. A properly set proportional control coefficient ensures that the current sharing adjustment process is both fast and stable, avoiding system oscillation or overshoot due to excessive gain, and also preventing slow current sharing response due to insufficient gain. In the current sharing algorithm, the target product obtained by multiplying the proportional control coefficient by the current difference is directly superimposed on the desired voltage value to form the final reference voltage of the second branch, thereby achieving accurate closed-loop current equalization control.

[0073] In one optional embodiment, a first current sample value and a second current sample value can be acquired in real time, and their average current value can be calculated, representing the average load current that each path should bear under ideal system conditions. Next, the current difference between the second current sample value and the average current value is calculated. This current difference reflects the deviation of the slave current from the average level, i.e., the current sharing error. Subsequently, this current difference is multiplied by a preset proportional control coefficient to obtain a target product, which is the adjustment amount used to correct the slave voltage. Finally, this target product is superimposed on the desired voltage value of the positive DC output bus to form the reference voltage value of the second voltage conversion branch. If the slave current is less than the average current value, the reference voltage value of the second voltage conversion branch is reduced, thereby reducing the output current; if the slave current is greater than the average current value, the reference voltage is increased to increase the current, achieving dynamic balance through this negative feedback mechanism.

[0074] Through the above settings, high-precision current balancing control is achieved with low computational complexity. By introducing a proportional control coefficient, the voltage setpoint can be linearly adjusted according to the current deviation, ensuring that the two DC-DC converters operate with almost no circulating current in steady state, keeping the current difference within a small range. Direct adjustment based on current deviation results in fast response and good stability, effectively avoiding uneven load distribution caused by device parameter dispersion or inconsistent line impedance. This improves the overall conversion efficiency of the system, reduces heat loss of power devices, and extends the service life of power electronic components, providing a solid technical guarantee for the efficient and reliable operation of high-power-density vehicle power supply systems.

[0075] In this embodiment of the application, the method further includes: acquiring operating status data corresponding to each voltage conversion branch, wherein the operating status data includes at least one of the following: temperature parameters, current parameters, and voltage parameters; determining whether there is an abnormal operating status branch based on the operating status data; generating a corresponding on / off control command in response to the existence of an abnormal operating status branch; and controlling the switching unit in the abnormal operating status branch to be in the off state based on the on / off control command.

[0076] The aforementioned operational status data refers to the set of operating parameters for each voltage conversion branch that the digital signal processor collects and monitors in real time. Specifically, this includes temperature, current, and voltage parameters. Temperature parameters reflect the thermal state of power devices to prevent overheating failure; current parameters monitor the output current of each branch to determine if overcurrent or uneven load distribution has occurred; and voltage parameters monitor the stability of the output voltage to identify overvoltage or undervoltage faults. This data forms the basis for health management and fault diagnosis, ensuring the system can react quickly before or when anomalies occur.

[0077] The aforementioned abnormal operating branch can refer to a voltage conversion branch where the monitored operating status data exceeds a preset safety threshold or a logical error occurs. For example, when the temperature of a DC voltage conversion exceeds 120°C, the output voltage spikes above 18V, or the current increases abnormally, that branch is identified as an abnormal operating branch. Identifying abnormal branches is a prerequisite for the system to perform fault isolation, aiming to prevent the fault from spreading and damaging other normal branches or downstream onboard electronic devices, such as the autonomous driving domain controller.

[0078] The aforementioned on / off control command refers to the control signal generated by the digital signal processor after detecting an abnormal operating branch, used to drive the switching unit. Its purpose is to quickly disconnect the electrical connection between the abnormal branch and the common DC output bus. When the on / off control command is issued, the switching unit in the abnormal operating branch switches to the off state, achieving bidirectional blocking, thereby physically isolating the faulty branch from the voltage conversion system. This ensures that the normal branch can seamlessly take over the load, maintaining the continuity and safety of the vehicle's low-voltage power supply system.

[0079] In one optional embodiment, a fault intelligent diagnosis and physical isolation mechanism based on real-time monitoring of multiple parameters is implemented. The digital signal processor continuously collects operating status data for each voltage conversion branch through a sensor network, focusing on temperature parameters such as power device junction temperature, current parameters, output current magnitude and ripple, and voltage parameters and output voltage stability. A preset safety threshold range is established; when any parameter exceeds the preset threshold, such as temperature exceeding 120°C, abnormal voltage rise to 18V, or severe current overshoot, the branch is determined to be in an abnormal operating state. Upon confirmation of the abnormality, a high-priority on / off control command is generated and sent to the switching unit drive circuit in the abnormal branch. The switching unit responds to the command by promptly forcibly disconnecting, severing the electrical connection between the positive output terminal of the filter circuit and the positive output terminal of the branch, achieving bidirectional blocking. This process is independent of the main control loop, ensuring reliable isolation operation even under extreme conditions such as communication delays or software glitches.

[0080] Through the above configuration, a highly reliable system-level fault self-healing and isolation capability is established. By monitoring multi-dimensional operating status in real time, potential faults, such as overheating trends or voltage drift, can be identified early, preventing fault escalation. When a serious fault is detected, the faulty branch can be isolated from the common bus in a timely manner through rapid physical disconnection of the hardware-level switching unit, preventing fault current or overvoltage surges from damaging downstream autonomous driving domain controllers or other loads. This closed-loop control mechanism of monitoring, judgment, and isolation improves the functional safety level of the power supply system, ensuring that in the event of a single module failure, the remaining healthy branches can take over the load, guaranteeing the uninterrupted operation of systems such as the vehicle's drive-by-wire chassis, and enhancing the safety and robustness of the entire vehicle's electrical system.

[0081] Figure 4 This is a schematic diagram of the control process of an optional voltage conversion system according to an embodiment of the present invention, such as... Figure 4 As shown, firstly, current sampling values ​​corresponding to the positive output terminals of at least two voltage conversion branches are acquired. Next, a first current sampling value corresponding to the positive output terminal of the first voltage conversion branch and a second current sampling value corresponding to the positive output terminal of the second voltage conversion branch (excluding the first voltage conversion branch) are determined. Based on the first and second current sampling values, a reference voltage value corresponding to each voltage conversion branch is determined. Based on the reference voltage value corresponding to each voltage conversion branch, a target pulse width modulation signal is generated. Finally, based on the target pulse width modulation signal, the switching state of the corresponding transistors in the voltage buck converter of each voltage conversion branch is controlled to control the at least two voltage conversion branches to perform voltage buck conversion on the first voltage to obtain the second voltage.

[0082] Figure 5 This is a schematic diagram of the control process of an optional voltage conversion system according to an embodiment of the present invention, such as... Figure 5 As shown, firstly, current sampling values ​​corresponding to the positive output terminals of at least two voltage conversion branches are acquired. Next, a first current sampling value corresponding to the positive output terminal of the first voltage conversion branch and a second current sampling value corresponding to the positive output terminal of the second voltage conversion branch (excluding the first voltage conversion branch) are determined. The desired voltage value corresponding to the positive DC output bus is obtained. Based on the desired voltage value, a reference voltage value corresponding to the first voltage conversion branch is determined. The average current value of the first and second current sampling values ​​is determined. The current difference between the average current value and the second current sampling value is determined. The target product of the proportional control coefficient and the current difference is determined. Based on the desired voltage value and the target product, the reference voltage value corresponding to the second voltage conversion branch is determined. Based on the reference voltage value corresponding to each voltage conversion branch, a target pulse width modulation signal is generated. Finally, based on the target pulse width modulation signal, the switching state of the corresponding transistors in the voltage buck converter of each voltage conversion branch is controlled to control the at least two voltage conversion branches to perform voltage buck conversion on the first voltage to obtain the second voltage.

[0083] Figure 6 This is a schematic diagram of the control process of another optional voltage conversion system according to an embodiment of the present invention, such as... Figure 6As shown, firstly, current sampling values ​​corresponding to the positive output terminals of at least two voltage conversion branches are acquired. Next, a first current sampling value corresponding to the positive output terminal of the first voltage conversion branch and a second current sampling value corresponding to the positive output terminal of the second voltage conversion branch (excluding the first voltage conversion branch) are determined. Based on the first and second current sampling values, a reference voltage value corresponding to each voltage conversion branch is determined. Based on the reference voltage value corresponding to each voltage conversion branch, a target pulse width modulation signal is generated. Then, based on the target pulse width modulation signal, the switching state of the corresponding transistors in the voltage buck converter of each voltage conversion branch is controlled to control the at least two voltage conversion branches to perform voltage buck conversion on the first voltage to obtain the second voltage. The system acquires the operating status data corresponding to each voltage conversion branch, wherein the operating status data includes at least one of the following: temperature parameters, current parameters, and voltage parameters; determines whether there is an abnormal operating status branch based on the operating status data; generates a corresponding on / off control command in response to the existence of an abnormal operating status branch; and controls the switching unit in the abnormal operating status branch to be in the off state based on the on / off control command.

[0084] The technical solution proposed in this application will be described below with reference to an optional embodiment. This application proposes a dual-redundant DC-DC converter system and its control method. It relates to the field of power management technology for new energy vehicles and intelligent connected vehicles, specifically to a high-reliability, high-power-density dual-redundant DC-DC converter system and its intelligent control method applied to on-board low-voltage power supply networks. The aim is to solve the technical problems existing in related technologies, such as insufficient reliability, slow dynamic response speed, low efficiency, and long fault switching time.

[0085] The technical solution proposed in this application achieves redundant switching. When the main DC-DC converter needs to be shut down due to over-temperature or over-current protection, the slave DC-DC converter can take over the load within microseconds through an OR gate diode controller. This feature ensures zero power interruption for loads such as the drive-by-wire chassis system, meets the functional safety requirements of the vehicle safety integrity level, and improves driving safety. It effectively eliminates circulating current and improves system efficiency. This application introduces a digital active current sharing algorithm, which, through real-time monitoring and dynamic adjustment, strictly controls the current difference between the two DC-DC converters within a small range. Efficiency is improved under light load conditions, and the thermal stress on power devices is reduced, extending the system's lifespan. It possesses fault self-healing and physical isolation capabilities. When the system detects a severe overvoltage anomaly in one path, such as an output voltage exceeding 16V, the control logic can promptly physically disconnect the faulty path through a solid-state switch. This rapid physical isolation mechanism prevents overvoltage surges from propagating to subsequent stages, thereby protecting the downstream autonomous driving domain controller from damage.

[0086] To achieve the above objectives, this application adopts the following technical solution: The proposed dual-redundant DC-DC converter system comprises three levels: power master topology, redundant control architecture, and current sharing and health management algorithms. Regarding the system topology, this system adopts a single-core, dual-drive architecture. Specifically, the system shares the same digital signal processor as the control unit and has two independent power links. At the input end, the two links share a high-voltage bus, each equipped with an independent electromagnetic interference filter and surge suppression circuit to ensure the independence and anti-interference capability of the input side. In the power stage, an interleaved parallel bidirectional active full-bridge topology is adopted. This topology is more suitable for bidirectional energy flow and facilitates soft switching, thereby reducing switching losses. The input sides of the two DC-DC converters are connected in parallel, and the output sides converge. At the output end, the two outputs drive low-on-resistance metal-oxide-semiconductor field-effect transistors through an ideal diode controller, and are connected to a common bus to power a 12V battery and various loads.

[0087] Regarding hardware redundancy and logic design, to address the circulating current issue, this application employs OR gate logic on the output side. Specifically, a dedicated ideal diode controller drives low-impedance transistors. When the output voltage of a channel is higher than the bus voltage, the controller quickly turns on the transistor for that channel, resulting in lower impedance; when the channel voltage is lower than the bus voltage, for example, when another channel is being powered, the controller promptly turns off the transistor, using the transistor's body diode for momentary blocking, and then cutting off the current path. This physically forced blocking solves the problem of backflow circulating current between the two outputs.

[0088] Regarding the control method, this application achieves high-reliability power supply through a master-slave adaptive current sharing and fault dynamic derating control strategy. Specific steps include: First, state synchronization and pre-charging: After system power-on, the digital signal processor first executes a self-test program. Both DC-DC converters simultaneously undergo soft-start, detecting the output capacitor voltage. To avoid a large inrush current during startup, the system first closes the pre-charging circuit. After the bus voltage stabilizes within the set range, the main contactor closes to complete the pre-charging process. Second, digital active current sharing control: This application employs the average current method. The digital signal processor uses a high-precision analog-to-digital converter to collect the output current of the first voltage conversion branch DC-DC converter and the second voltage conversion branch DC-DC converter in real time. The system calculates the average value of the two currents. The first voltage conversion branch is designated as the master, responsible for voltage loop control to stabilize the output voltage; the second voltage conversion branch is designated as the slave, and the reference voltage can be dynamically adjusted according to the current deviation. When the output current of the slave circuit is detected to be less than the average current, the control algorithm slightly raises the output voltage setpoint of the slave circuit, allowing it to share more current. Conversely, when the output current of the slave circuit is detected to be greater than the average current, the control algorithm slightly lowers the output voltage setpoint of the slave circuit, allowing it to share less current. This closed-loop regulation frequency is much higher than the load change frequency, resulting in a smaller difference between the two currents and achieving accurate current sharing. The third step involves fault mode identification and switching. The system monitors output voltage, output current, temperature, and controller LAN communication status in real time, and adopts differentiated processing strategies for different fault modes. For single-channel overcurrent or overtemperature faults, when the temperature of a certain channel reaches a preset threshold, such as 120℃, the digital signal processor gradually reduces the current setpoint of that channel to zero amperes using a current sharing algorithm. At this time, the converter of that channel enters an "idle" state, maintaining the synchronous rectifier transistor on as a heat dissipation channel and not providing energy output. The other DC-DC converter independently bears 100% of the load, achieving thermal derating redundancy and ensuring continuous power supply. For severe overvoltage faults, when the voltage sampling feedback loop fails, causing a certain output to spike to a dangerous level, such as 18V, the hardware comparator will trigger an interrupt. The digital signal processor (DSP) quickly blocks the pulse-width modulation (PWM) drive signal of the faulty output and drives the series solid-state circuit breaker at the output to disconnect rapidly. The faulty output is promptly physically disconnected from the system, and the normal output takes over all loads. Due to the presence of ideal diodes, the bus voltage of the normal output will not flow back to the damaged faulty output, achieving fault isolation. The fourth step is diagnosis and reporting. The system reports its health status to the vehicle domain controller in real time via the high-speed Controller Area Network (CLAN) bus, predicts the remaining lifespan of power devices, and records detailed fault logs for subsequent maintenance and data analysis.

[0089] The reference voltage value corresponding to the second voltage transformation branch in this application It can be represented as follows:

[0090] ;

[0091] in, Indicates the desired voltage value; Indicates the proportional control coefficient; The average current value is the arithmetic mean of the first and second current sample values. This represents the second current sample value.

[0092] The technical solution of this application will be described in detail below with reference to specific embodiments. This embodiment takes a pure electric passenger vehicle equipped with Level 3 autonomous driving function as an example to illustrate the complete working process of the dual-redundant DC-DC converter system of this application under typical driving scenarios. In the system startup phase, after the vehicle is powered on, the vehicle controller sends a startup command to the digital signal processor through the high-speed controller area network bus. The system then enters the pre-charging phase. In this phase, the pre-charging contactor closes, and the high-voltage current is current-limited to the bus capacitor through the pre-charging resistor to prevent the capacitor from being charged instantaneously and causing current surge. The two DC-DC converters execute a soft-start program, and the switching frequency gradually increases from 0 to 100kHz. During this process, the first voltage conversion branch DC-DC converter outputs a current of 15A, and the second voltage conversion branch DC-DC converter outputs a current of 15A. The two converters start synchronously, smoothly establish the bus voltage, and no surge current is generated. After the pre-charging is completed, the main contactor closes, and the system officially enters the steady-state operation phase. During steady-state operation, the digital signal processor continuously executes the active current sharing algorithm. Assuming an initial state, the system detects an output current of 45A for the first voltage conversion branch and 42A for the second voltage conversion branch. The system calculates an average current of 43.5A. Based on the current-sharing algorithm, the system fine-tunes the voltage reference value of the second voltage conversion branch, slightly increasing its output. Ultimately, the two currents quickly converge to 60A, with the current deviation kept within a small range. When the vehicle encounters an uphill condition, the power demand of the electric power steering system increases, causing the total load to jump from 120A to 182A. The digital signal processor promptly performs dynamic adjustments: the current in the first voltage conversion branch increases from 60A to 91A, and the current in the second voltage conversion branch also increases from 60A to 91A, with the dynamic deviation controlled within 2%. The system quickly returns to current-sharing mode, ensuring stable output voltage and meeting the power supply requirements during sudden load changes. Regarding the fault occurrence and switching process, assuming that during driving, a silicon carbide transistor in the DC-DC converter of the first voltage conversion branch experiences a short-circuit breakdown, causing the output voltage to surge from the normal 13.5V to 18V. The hardware overvoltage comparator promptly detects the abnormal voltage and immediately triggers an interrupt request from the digital signal processor (DSP). The DSP promptly blocks the pulse-width modulation (PWM) drive signal of the first voltage conversion branch, stopping its power switching. The ideal diode controller at the processor's instruction output drives the back-to-back connected transistors to promptly turn off, physically isolating the first voltage conversion branch from the system. At this point, the output current of the DC-DC converter in the second voltage conversion branch rapidly increases from 90A to 180A, taking over the entire load. The entire switching process is short, with minimal voltage drop on the common bus and a short duration. Because the electric power steering controller has an internal support capacitor sufficient to maintain power supply, the vehicle's steering and braking functions are unaffected, and the driver is unaware of the change, achieving redundant switching.Degraded operation and load management: Upon detecting a fault in the first voltage conversion branch, the system enters degraded operation mode. The DC-DC converter in the second voltage conversion branch independently handles a 180A load, which is higher than the rated value but within the short-term overload allowable range. The digital signal processor reports a fault code to the vehicle controller via the high-speed controller area network bus, and the electrical system fault indicator light on the instrument panel illuminates, reminding the driver to leave the highway or a safe area as soon as possible. The vehicle controller cuts off non-loads such as seat heating and air conditioning compressors to reduce the burden on the DC-DC converter in the second voltage conversion branch, ensuring that the power supply to the drive-by-wire chassis systems, such as steering and braking, does not exceed the predetermined time until the vehicle is safely driven to a service area for repair.

[0093] This application proposes a master-slave dynamic derating control strategy. Under non-fault conditions of the dual DC-DC converters, a digital current sharing algorithm balances the load to ensure efficient operation; under fault conditions, the current setpoint is gradually drated to zero, achieving "soft" redundancy switching. This strategy avoids the back electromotive force generated when relays or contactors suddenly disconnect, protecting power devices and loads, and improving system smoothness and reliability. An integrated structure of the secondary OR gate controller and solid-state circuit breaker is designed. An ideal diode controller and solid-state switch are integrated into the DC-DC converter module, replacing the external distribution box. This module-level fault self-isolation design saves space, simplifies wiring connections, improves system integration and anti-interference capabilities, and achieves microsecond-level physical fault isolation. A hierarchical power supply management strategy based on load importance is implemented. After a single-path fault, the system can proactively disconnect unnecessary loads, such as comfort configurations, based on battery state of charge and load level, prioritizing power supply to safety-critical loads such as the drive-by-wire chassis. This intelligent load management extends the system's availability time in fault modes and enhances the vehicle's safety redundancy. Furthermore, several alternative solutions exist to achieve the same application objective for the aforementioned technical points. For example, in current sharing control, besides the average current method, the master-slave offset voltage method or the droop characteristic method can also be used to achieve dynamic balance between the two current paths. Regarding fault isolation, in addition to solid-state circuit breakers, mechanical relays combined with fast-acting fuses can be used to disconnect fault paths within microseconds to milliseconds. As for topology, besides interleaved parallel bidirectional active full-bridge circuit breakers, different topologies such as half-bridge and full-bridge are acceptable as long as they achieve the same dual-path redundancy function.

[0094] This application proposes a dual-redundant DC-DC converter system and its control method. Through an innovative single-core dual-drive topology, digital active current sharing algorithm, and integrated fault isolation hardware design, it effectively addresses the shortcomings of existing vehicle-mounted DC-DC converter systems in terms of reliability, efficiency, and safety. It achieves microsecond-level redundancy switching, meeting the extremely high functional safety requirements of high-level autonomous driving for the power supply system. Furthermore, it improves system energy efficiency through intelligent current sharing and load management.

[0095] Embodiments of this application also provide a vehicle, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods described in various embodiments of this application when it runs.

[0096] The aforementioned memory can refer to devices inside a computer used to store data and programs, including RAM, hard disks, etc. RAM can be used to temporarily store running programs and data, while hard disks can be used to store programs and data long-term. Memory enables the computer to read and write data and execute programs. The aforementioned processor is responsible for executing instructions in computer programs and performing data processing. It can also be responsible for controlling and executing various operations, including arithmetic operations, logical operations, and data transmission.

[0097] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0098] The aforementioned computer storage media can refer to the media used in computer memory to store certain discontinuous physical quantities. Computer storage media mainly include semiconductors, magnetic cores, magnetic drums, magnetic tapes, laser discs, etc. Computer-readable storage media include stored programs, which can be a set of instructions that a computer can recognize and execute, running on an electronic computer to meet certain information needs.

[0099] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0100] The aforementioned computer program products can refer to software programs that have been written, tested, and released, and can run on computers or other devices. Computer program products can include application programs, operating systems, utility software, etc., used to achieve specific functions or solve specific problems.

[0101] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium for storing a computer program that, when executed by a processor, implements the methods in various embodiments of this application.

[0102] The aforementioned non-volatile computer-readable storage medium can refer to a medium for storing data. Non-volatile computer-readable storage media can retain data without loss when power is off and can be used to store long-term data, such as operating systems, applications, and user files. Non-volatile storage media can include hard disk drives, solid-state drives, optical disks, and flash memory storage devices, etc.

[0103] Embodiments of this application also provide a computer program that, when executed by a processor, implements the methods described in the various embodiments of this application.

[0104] The aforementioned computer program can refer to a set of instructions used to tell the computer to perform specific tasks or operations. Computer programs can be written by programmers using specific programming languages ​​and can include algorithms, data structures, logic, and control flow. Computer programs can be used for a variety of purposes, including application software, operating systems, etc.

[0105] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0106] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0107] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0108] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0109] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0110] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A voltage conversion system, characterized in that, include: At least two voltage conversion branches, wherein the positive input terminal of each voltage conversion branch is connected to the positive DC input bus, the negative input terminal of each voltage conversion branch is connected to the negative DC input bus, the positive output terminal of each voltage conversion branch is connected to the positive DC output bus, and the negative output terminal of each voltage conversion branch is connected to the negative DC output bus. A digital signal processor is connected to the control terminal of the corresponding transistor in each voltage conversion branch to control the at least two voltage conversion branches to perform voltage step-down conversion on the first voltage to obtain a second voltage. The first voltage represents the voltage between the positive DC input bus and the negative DC input bus, and the second voltage represents the voltage between the positive DC output bus and the negative DC output bus.

2. The voltage conversion system according to claim 1, characterized in that, Each voltage transformation branch includes: A voltage buck converter, wherein the positive input terminal of the voltage buck converter is connected to the positive input terminal of each voltage conversion branch, and the negative input terminal of the voltage buck converter is connected to the negative input terminal of each voltage conversion branch, wherein the corresponding transistor in the voltage buck converter is used to respond to the target pulse width modulation signal sent by the digital signal processor to perform voltage bucking processing on the first voltage; A filter circuit is provided, wherein the positive input terminal of the filter circuit is connected to the positive output terminal of the voltage buck converter, the negative input terminal of the filter circuit is connected to the negative output terminal of the voltage buck converter, and the negative output terminal of the filter circuit is connected to the negative output terminal of each voltage conversion branch. The filter circuit is used for current filtering. A switching unit is provided, wherein the input terminal of the switching unit is connected to the positive output terminal of the filter circuit, and the output terminal of the switching unit is connected to the positive output terminal of each voltage conversion branch. The switching unit is used to turn on or off in response to an on / off control command sent by the digital signal processor. When the switching unit is in the on state, the positive output terminal of the filter circuit is connected to the positive output terminal of each voltage conversion branch. When the switching unit is in the off state, the positive output terminal of the filter circuit is bidirectionally blocked from the positive output terminal of each voltage conversion branch.

3. The voltage conversion system according to claim 2, characterized in that, The switching unit includes: A first transistor, the source of which is connected to the input terminal of the switching unit, and the gate of which is connected to the digital signal processor; The second transistor has its drain connected to the drain of the first transistor, its source connected to the output of the switching unit, and its gate connected to the digital signal processor. The digital signal processor is further configured to control the on / off state of the switching unit by controlling the on / off state of the first transistor and the second transistor.

4. A control method for a voltage conversion system, characterized in that, The method, applied to the voltage conversion system according to any one of claims 1 to 3, comprises: Collect the current sampling value corresponding to the positive output terminal of each voltage conversion branch in at least two voltage conversion branches; The target pulse width modulation signal is generated based on the current sampling value corresponding to the positive output terminal of each voltage conversion branch. Based on the target pulse width modulation signal, the on / off state of the corresponding transistor in the voltage buck converter in each voltage conversion branch is controlled to control the at least two voltage conversion branches to perform voltage buck conversion on the first voltage to obtain the second voltage.

5. The control method for the voltage conversion system according to claim 4, characterized in that, Based on the current sampling value corresponding to the positive output terminal of each voltage conversion branch, a target pulse width modulation signal is generated, including: Determine the first current sampling value corresponding to the positive output terminal of the first voltage conversion branch and the second current sampling value corresponding to the positive output terminal of the second voltage conversion branch other than the first voltage conversion branch in the at least two voltage conversion branches. Based on the first current sampling value and the second current sampling value, determine the reference voltage value corresponding to each voltage transformation branch; The target pulse width modulation signal is generated based on the reference voltage value corresponding to each voltage transformation branch.

6. The control method for the voltage conversion system according to claim 5, characterized in that, Based on the first current sample value and the second current sample value, determine the reference voltage value corresponding to each voltage transformation branch, including: Obtain the desired voltage value corresponding to the positive DC output bus; Based on the desired voltage value, determine the reference voltage value corresponding to the first voltage transformation branch; Based on the desired voltage value, the first current sample value, and the second current sample value, the reference voltage value corresponding to the second voltage transformation branch is determined.

7. The control method for the voltage conversion system according to claim 6, characterized in that, Based on the desired voltage value, the first current sample value, and the second current sample value, the reference voltage value corresponding to the second voltage transformation branch is determined, including: Determine the average current value of the first current sample value and the second current sample value; Determine the current difference between the average current and the second current sample value; Determine the target product of the proportional control coefficient and the current difference; Based on the product of the desired voltage value and the target, the reference voltage value corresponding to the second voltage transformation branch is determined.

8. The control method for the voltage conversion system according to any one of claims 4 to 7, characterized in that, The method further includes: Obtain the operating status data corresponding to each voltage conversion branch, wherein the operating status data includes at least one of the following: temperature parameter, current parameter, and voltage parameter; Based on the operational status data, determine whether there are any branches with abnormal operational status; In response to the existence of the abnormal operating branch, a corresponding on / off control command is generated; Based on the on / off control command, the switching unit in the abnormal operating branch is controlled to be in the off state.

9. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, executes the control method of the voltage conversion system according to any one of claims 4 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device containing the storage medium to perform the control method of the voltage conversion system according to any one of claims 4 to 8.

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