Power-on slow start and surge suppression method for low-altitude vehicle mission payload

Abstract

This application relates to the field of airborne power management for low-altitude aircraft, and provides a power-on soft start and surge suppression method for low-altitude aircraft mission payloads. The method is applied to low-altitude aircraft and includes: upon receiving a power-on command, first performing a pre-charging operation on the energy storage capacitor on the input side of the power supply system; after pre-charging, first outputting multiple 48V DC voltages, then starting the DC-DC conversion module to output a 24V DC voltage; during the operation of the 48V and 24V DC voltage outputs, the load current of each branch is monitored in real time; when a surge current exceeding a preset threshold is detected, a current limiting adjustment operation is performed to limit the surge current within a safe range; when an abnormal input voltage or an overcurrent fault is detected in a branch, the output of the corresponding branch is cut off, while maintaining normal power supply to non-faulty branches. This method is adapted to the special operating environment and power supply requirements of low-altitude aircraft mission payloads.

Description

Technical Field

[0001] This application relates to the field of airborne power management technology for low-altitude aircraft, and in particular to a power-on soft start and surge suppression method for low-altitude aircraft mission payloads. Background Technology

[0002] With the rapid development of the low-altitude economy, low-altitude aircraft, including multi-rotor UAVs, vertical takeoff and landing (VTOL) aircraft, and manned electric vertical takeoff and landing (EVTOL) aircraft, are widely used in urban air traffic, low-altitude inspection and monitoring, emergency firefighting, and smart logistics. The types of mission payloads carried by low-altitude aircraft are becoming increasingly diverse, including optoelectronic pods, surveying and mapping sensing equipment, communication relay equipment, and emergency rescue payloads. The power supply requirements of different payloads vary significantly, often involving multiple 48-volt high-power payloads and multiple 24-volt auxiliary payloads simultaneously. This places extremely high demands on the power-on stability, surge suppression capabilities, and fault isolation capabilities of the airborne power supply system.

[0003] Currently, existing technologies for power-on control and surge suppression of airborne power supply systems are mainly divided into two categories: one is a passive protection scheme based on hardware circuits, which achieves surge suppression and overcurrent protection by connecting thermistors in series, transient suppression diodes in parallel, and fuses in the power supply branch; the other is a soft-start control method for single power supply, which achieves power-on surge suppression of single output through a single slow-boost logic.

[0004] The existing solution is not adapted to the power supply architecture of dual redundant 48V input and multiple 48V and 24V multi-level output for low-altitude aircraft mission payloads. It lacks targeted hierarchical power-on timing control logic. When multiple loads are powered on at the same time, the charging impact of capacitive loads and the superposition of multiple starting currents can easily generate surge currents far exceeding the rated values ​​of the devices, causing input fuses to blow, power modules to be damaged, and even interfering with the power supply stability of the aircraft's flight control system, leading to flight safety accidents. Summary of the Invention

[0005] This application provides a power-on soft start and surge suppression method for low-altitude aircraft mission payloads, aiming to solve the problem that there is currently no complete power-on control and surge suppression solution for power supply of multiple mission payloads of low-altitude aircraft.

[0006] In a first aspect, embodiments of this application provide a power-on soft start and surge suppression method for low-altitude aircraft mission payloads, applied to low-altitude aircraft. The power supply system for the mission payload of the low-altitude aircraft receives two 48-volt DC inputs and outputs multiple 48-volt DC voltages and multiple 24-volt DC voltages, including: Upon receiving the power-on command, a pre-charging operation is first performed on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches the preset pre-charging completion threshold, thus completing the pre-charging. After pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-DC conversion module is started to output 24V DC voltage. A soft start operation is performed during the output of 48V DC voltage and 24V DC voltage, gradually increasing the output voltage to the rated operating voltage. During operation with 48V DC and 24V DC output, the load current of each branch is monitored in real time. When the surge current exceeds the preset threshold, current limiting adjustment is performed to limit the surge current within a safe range. When an abnormal input voltage or an overcurrent fault is detected in a branch, the output of the corresponding branch is cut off, and the normal power supply to the non-faulty branches is maintained.

[0007] In some embodiments, after receiving the power-on command, a pre-charging operation is first performed on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches a preset pre-charging completion threshold, thus completing the pre-charging. This includes: after receiving the power-on command, performing a constant current pre-charging operation on the energy storage capacitor with a first preset current threshold, and collecting the voltage value across the energy storage capacitor in real time; when the voltage value across the energy storage capacitor reaches the first preset voltage threshold, adjusting the current limiting threshold to a second preset current threshold, and continuing to perform the constant current pre-charging operation until the voltage value across the energy storage capacitor reaches the preset pre-charging completion threshold, thus stopping the pre-charging operation; wherein the second preset current threshold is greater than the first preset current threshold, and the first preset voltage threshold is less than the pre-charging completion threshold.

[0008] In some embodiments, after the pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-to-DC converter module is started to output 24V DC voltage. This includes: after the pre-charging is completed, each 48V DC voltage output branch is started sequentially at a preset time interval; after each 48V DC voltage output branch is started and the output voltage is stable, the next 48V DC voltage output branch is started; after all 48V DC voltage output branches have stably output the rated voltage, the DC-to-DC converter module is started, and then each 24V DC voltage output branch is started sequentially at a preset time interval.

[0009] In some embodiments, the step of performing a soft-start operation during the output of 48V DC voltage and 24V DC voltage, gradually increasing the output voltage to the rated operating voltage, includes: during the startup process of each DC voltage output branch, gradually increasing the output voltage of the corresponding branch according to a preset fixed slope, and collecting the output voltage value and output current value of the corresponding branch in real time; when the output current value exceeds the preset soft-start current limiting threshold, pausing the output voltage increase operation, and continuing to increase the output voltage according to the preset slope after the output current value falls back to within the soft-start current limiting threshold, until the output voltage reaches the rated operating voltage.

[0010] In some embodiments, the real-time detection of the load current of each branch during the operation of the 48V DC voltage and 24V DC voltage output includes: continuously sampling the output current of each branch at a fixed sampling frequency during the normal operation of each DC voltage output branch; performing sliding filtering on the multiple continuously collected current sampling values ​​to obtain the real-time load current value of the corresponding branch; and synchronously sampling and filtering the input voltage of each branch to obtain the real-time input voltage value of the corresponding branch.

[0011] In some embodiments, when the surge current is detected to exceed a preset threshold, a current limiting adjustment operation is performed to limit the surge current within a safe range. This includes: when the real-time load current value exceeds the preset surge current threshold, immediately performing a current limiting adjustment operation, gradually reducing the output conduction capability of the corresponding branch according to a preset adjustment step size, and limiting the output current of the corresponding branch to within a preset safe current limiting threshold; when the real-time load current value falls back to within the surge current threshold, gradually restoring the output conduction capability of the corresponding branch to maintain the stability of the output voltage.

[0012] In some embodiments, the step of cutting off the output of the corresponding branch and maintaining the normal power supply of the non-faulty branches when an abnormal input voltage or an overcurrent fault is detected includes: when the real-time input voltage value exceeds a preset normal voltage range, it is determined that the input voltage is abnormal, and the power supply of all output branches is immediately cut off; when the real-time load current value of a single branch continuously exceeds a preset overcurrent threshold for a preset duration, it is determined that an overcurrent fault has occurred in the corresponding branch, the output of the corresponding faulty branch is immediately cut off, while maintaining the normal power supply of the remaining non-faulty branches, and recording the fault information of the corresponding faulty branch.

[0013] In some embodiments, the method further includes: before the low-altitude aircraft performs a flight mission, obtaining the type information and rated parameter information of the currently mounted mission payload, calling the pre-stored historical operation data of the corresponding payload type, using a machine learning model to self-tune the current threshold of the pre-charging operation, the voltage slope of the soft start operation, and the current limiting threshold of the surge suppression, generating control parameters adapted to the current mission payload, and executing the corresponding control parameters during the current power-on process.

[0014] In some embodiments, the method further includes: during the flight of the low-altitude aircraft, receiving mission load action commands sent by the flight control system in real time, predicting the load change trend within a preset time period through a preset load prediction model, adjusting the current limiting threshold and output adjustment parameters of the corresponding branch in advance according to the predicted load change trend, completing the pre-adjustment of control parameters before the load changes abruptly, and suppressing the surge current caused by the load change abruptly.

[0015] In some embodiments, the method further includes: acquiring power-on data, surge suppression data, and fault data of the power supply system during each flight mission; constructing a full lifecycle operation database of the power supply system; training and analyzing the data in the database using a deep learning model to obtain the performance aging trend of the power supply system; and periodically updating the control parameters for pre-charging, soft start-up, and surge suppression according to the performance aging trend to maintain stable operation of the power supply system throughout its entire lifecycle.

[0016] This application addresses the power supply architecture of a low-altitude aircraft's mission payload, featuring dual 48V inputs and multiple 48V and 24V outputs. It designs a complete control logic of pre-charging followed by tiered power-up. By pre-charging the input-side energy storage capacitors, it suppresses initial input surge currents at the source, preventing damage to the airborne power supply and front-end components from the large current surge during capacitive load power-up. By employing a tiered power-up sequence—first the 48V branch, then the 24V branch—along with independent soft-start operations for each output branch, it avoids the superposition of starting currents from simultaneous power-up of multiple branches with different voltage levels, significantly reducing peak currents during power-up and improving stability when multiple loads are powered simultaneously. During branch operation, by real-time monitoring of the load current of each branch, it actively performs closed-loop current limiting regulation of surge currents, effectively suppressing continuous surge currents caused by load insertion / removal and sudden load changes. Compared to traditional passive hardware protection, this approach offers stronger surge suppression capabilities, faster response speeds, and eliminates the risk of irreversible component damage, thus improving the long-term operational reliability of the power supply system. Meanwhile, by designing a graded fault protection logic, it can distinguish between global input voltage anomalies and single-branch overcurrent faults. For single-branch faults, only the corresponding faulty branch is disconnected, maintaining normal power supply to non-faulty branches. This achieves precise fault isolation, avoiding the problem of total load failure caused by a single load fault, and significantly improving the redundancy and flight safety of power supply for low-altitude aircraft mission payloads. This invention fully covers the entire process control of power-on pre-charging, graded soft start, active surge suppression during operation, and graded fault isolation, and is fully adaptable to the special operating environment and power supply requirements of low-altitude aircraft mission payloads.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart illustrating the steps of a power-on soft start and surge suppression method for low-altitude aircraft mission payloads provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a low-altitude aircraft provided in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of a power distribution board for a mission payload of a low-altitude aircraft, provided in one embodiment of this application. Figure 4This is a schematic diagram of the power module circuit of a power distribution board for a mission payload of a low-altitude aircraft, provided in one embodiment of this application. Figure 5 This is a schematic block diagram of a power-on soft start and surge suppression system for low-altitude aircraft mission payloads provided in one embodiment of this application; Figure 6 This is a schematic block diagram of the structure of a low-altitude aircraft provided in one embodiment of this application.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0023] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, the terms "first" and "second" are used in the embodiments of the present invention to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0024] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0026] With the rapid development of the low-altitude economy, low-altitude aircraft, including multi-rotor UAVs, vertical takeoff and landing (VTOL) aircraft, and manned electric vertical takeoff and landing (EVTOL) aircraft, are widely used in urban air traffic, low-altitude inspection and monitoring, emergency firefighting, and smart logistics. The types of mission payloads carried by low-altitude aircraft are becoming increasingly diverse, including optoelectronic pods, surveying and mapping sensing equipment, communication relay equipment, and emergency rescue payloads. The power supply requirements of different payloads vary significantly, often involving multiple 48-volt high-power payloads and multiple 24-volt auxiliary payloads simultaneously. This places extremely high demands on the power-on stability, surge suppression capabilities, and fault isolation capabilities of the airborne power supply system.

[0027] Currently, existing technologies for power-on control and surge suppression of airborne power supply systems are mainly divided into two categories: one is a passive protection scheme based on hardware circuits, which achieves surge suppression and overcurrent protection by connecting thermistors in series, transient suppression diodes in parallel, and fuses in the power supply branch; the other is a soft-start control method for single power supply, which achieves power-on surge suppression of single output through a single slow-boost logic.

[0028] Existing technical solutions have insurmountable technical defects: First, the existing solution is not adapted to the power supply architecture of dual redundant 48V input and multiple 48V and 24V multi-level output for low-altitude aircraft mission payloads. It lacks targeted hierarchical power-on timing control logic. When multiple loads are powered on at the same time, the charging impact of capacitive loads and the superposition of multiple starting currents can easily generate surge currents far exceeding the rated values ​​of the devices, causing input-side fuses to blow, power module damage, and even interfering with the power supply stability of the aircraft's flight control system, leading to flight safety accidents.

[0029] Second, existing passive surge protection solutions can only suppress instantaneous peak voltages and cannot actively close-loop regulate continuous surge currents caused by load changes or load insertion / removal. Their surge suppression capability is limited, and the protection devices are prone to irreversible damage after activation, which cannot meet the long-endurance and high-reliability requirements of low-altitude aircraft. Existing single-path soft-start solutions do not consider the coordinated control of multiple branches with multiple voltage levels, and cannot solve the problem of superimposed impacts from multiple branches.

[0030] Third, the fault protection logic of the existing solution is relatively simple. When an anomaly occurs, the power supply is cut off globally, which cannot achieve precise isolation of a single faulty branch. A fault in a single mission payload will cause all payloads to fail, and may even affect the power supply safety of the main system of the aircraft. It cannot meet the safety requirements of ensuring the continuous operation of other systems when a payload fails during the flight of a low-altitude aircraft.

[0031] Fourth, existing technical solutions are mostly designed for ground-based industrial power supply and vehicle-mounted power supply scenarios, without considering the special operating environment of low-altitude aircraft, such as high-altitude low temperature, strong vibration, and frequent dynamic changes in load. They cannot take into account the full-process power supply safety control, including power-on soft start, active surge suppression during operation, and fault classification isolation. Currently, there is no complete power-on control and surge suppression solution for power supply of multiple mission payloads of low-altitude aircraft.

[0032] To solve the above problem, please refer to Figure 1 This application provides a power-on soft start and surge suppression method for low-altitude aircraft mission payloads, applicable to, for example... Figure 2 The low-altitude aircraft shown has a corresponding mission payload power supply system that receives two 48-volt DC inputs and outputs multiple 48-volt DC voltages and multiple 24-volt DC voltages.

[0033] In some embodiments, such as Figure 3 As shown, the universal mission payload power distribution board for low-altitude aircraft is a multi-layer PCB board structure, featuring lightweight, high integration, and high reliability, and is suitable for the airborne installation environment of low-altitude aircraft. The attached figures include a front layout view and a side structural view of the power distribution board, fully demonstrating the layout and structure of the onboard components and interfaces. The power distribution board integrates dual-redundant input circuits, energy storage and filtering circuits, main power control circuits, DC-DC converter circuits, multi-channel independent output control circuits, sampling and protection circuits, and microcontroller minimum system circuits, fully implementing the method provided in the embodiments of this application.

[0034] The front of the power distribution board features the main interfaces and component layout. The PCB board has a rectangular structure with circular mounting holes at the four corners for securing the power distribution board within the onboard equipment bay of the low-altitude aircraft. The specific layout and functions are as follows: Along the left edge of the PCB board, seven terminal blocks are arranged from top to bottom. The first, third, fourth, fifth, and seventh are two-hole high-current terminal blocks, serving as four 48V DC output interfaces, corresponding to the four 48V output branches in Embodiment 2. The second and sixth are two-hole terminal blocks with fan markings, which can be used as power supply interfaces for airborne cooling fans, adapting to the heat dissipation requirements of high-power loads. The negative terminals of all left-side interfaces are connected to the system analog ground AGND, and the positive terminals are connected to the 48V input bus through an independent controllable power switch.

[0035] The rectangular blank area in the middle of the PCB board is the core mounting position for the microcontroller minimum system, DC-DC converter module, and main power switching device. The microcontroller is located in the center of this area, the DC-DC converter module is located on the right side of this area to realize the isolation conversion from 48V input to 24V output, and the main power switching device is located on the left side of this area to achieve pre-charge control in conjunction with the input-side energy storage capacitor.

[0036] Along the right edge of the PCB board, six 2-hole terminal blocks are arranged from top to bottom as five 24V DC output interfaces, with one spare expansion interface reserved, corresponding to the five 24V output branches in Embodiment 2; the negative terminals of all right-side interfaces are connected to the system power ground GND, and the positive terminals are connected to the 24V output bus through an independent controllable power switch.

[0037] The top and bottom ends of the PCB board are each equipped with two circular three-core aviation connectors, which can be used for the expansion of airborne backup power supply and signal interaction. The bottom right corner of the PCB board is equipped with SMB-packaged transient suppression diodes, surface mount resistors and capacitors, and other auxiliary devices to achieve electrostatic protection and filtering functions for input and output.

[0038] Two 220uF / 50V electrolytic capacitors are connected in parallel at the input position on the left side of the PCB board as input-side energy storage capacitors, corresponding to the pre-charge operation object in Embodiment 1, to achieve smooth filtering and energy storage of the input voltage.

[0039] On the right side of the PCB board, two 220uF / 50V electrolytic capacitors are connected in parallel as energy storage capacitors for the 24V output side. At the same time, an SMBJ24CA transient suppression diode is connected in parallel to achieve passive surge protection for the 24V output, corresponding to the active and passive dual protection system in Example 5.

[0040] The PCB board has a 4-layer fiberglass board structure. The top and bottom layers are signal and power layers, respectively, while the two middle layers are ground and power layers, which isolates high-voltage and low-voltage circuits, improves electromagnetic compatibility performance, and is suitable for strong electromagnetic environments on air.

[0041] On the left and right sides of the PCB board, terminal blocks are vertically soldered. The pins of the connectors pass through the pads on the PCB board and are reliably electrically connected by wave soldering. The height of the connectors is consistent to ensure flatness during installation.

[0042] In the middle of the PCB board, from left to right, are soldered a power relay, an energy storage electrolytic capacitor, a DC-DC power supply module, and a microcontroller core board. All components are surface-mount or through-hole soldered to ensure reliable connection under vibration conditions and adapt to the strong vibration conditions during the flight of low-altitude aircraft.

[0043] All power circuits use wide copper foil wiring to meet high current carrying requirements. Signal circuits use differential wiring to improve anti-interference capability. An isolation slot design is used between input and output circuits to achieve strong and weak current isolation and prevent high-voltage side faults from being conducted to the low-voltage side.

[0044] Dual 48V input interfaces on the left side enable redundant power supply; in the event of a single input failure, the other input can maintain normal system operation, enhancing power redundancy. Each 48V and 24V output branch is equipped with an independent controllable power switch, sampling circuit, and drive circuit. The microcontroller can independently control the on / off state, soft start, current limiting adjustment, and fault isolation of each branch, implementing all the control logic described in the above embodiments. Transient suppression diodes are configured in the hardware to provide instantaneous spike protection, while active current limiting adjustment as described in the software achieves continuous surge suppression, forming a dual protection system combining active and passive measures. The onboard microcontroller has built-in complete control firmware, capable of independently executing the entire process control including pre-charging, graded power-on soft start, real-time sampling, surge suppression, and fault protection. It can also communicate with the flight control system in real time via the CAN bus, reporting status information and fault alarms, and receiving control commands from the flight control system.

[0045] The power distribution board has reserved spare output interfaces and expansion plug interfaces, which can flexibly expand the output branches according to the number and type of mission payloads; at the same time, the microcontroller firmware supports online parameter configuration and upgrades, which can be adapted to different types of low-altitude aircraft and mission payloads, and has strong versatility and expandability.

[0046] The power distribution board provides a complete hardware platform for the aforementioned multi-channel power-on soft start and surge suppression methods. It features high integration, high reliability, and strong anti-interference capabilities, making it fully adaptable to the special operating environment of low-altitude aircraft. At the same time, through independent branch control design, it realizes all the control logic of the method, which can effectively suppress power-on impact and surge current during operation, achieve precise fault isolation, and greatly improve the safety and stability of power supply for low-altitude aircraft mission payloads.

[0047] In some embodiments, such as Figure 4 As shown in the attached figure, the main power circuit diagram of the power supply system for the task payload upon which this method is based is the core circuit of the power module. All control logic of this method is implemented through a matching microcontroller, sampling circuit, and drive circuit, specifically including: The dual-redundant DC input interface unit, comprising interface J1 and interface J2, both use 2-pin industrial-grade terminals and serve as the system's dual 48V DC redundant input interfaces, adapting to the redundancy and safety design requirements of airborne power supply for low-altitude aircraft. Pin 2 of interface J1 is connected to the positive terminal of the 48V input bus, and pin 1 is connected to the system analog ground AGND. Pin 2 of interface J2 is connected in parallel to the positive terminal of the 48V input bus, and pin 1 is connected in parallel to the system analog ground AGND. The two inputs employ a parallel redundancy design; if one input line experiences an open circuit or poor contact, the other input can maintain normal system power supply, preventing a single input failure from causing the entire mission payload to fail and improving power supply reliability during flight.

[0048] The input-side energy storage unit includes electrolytic capacitors C1 and C2. Both capacitors are high-temperature resistant aluminum electrolytic capacitors with a rated capacitance of 220 microfarads and a rated withstand voltage of 50 volts, suitable for the high-altitude, low-temperature operating environment of low-altitude aircraft. The positive terminals of capacitors C1 and C2 are connected in parallel to the positive terminal of the 48-volt input bus, and the negative terminals of capacitors C1 and C2 are connected in parallel to the system analog ground AGND. First, it smooths the ripple of the 48-volt input voltage and suppresses conducted noise in the airborne electrical environment. Second, as the core energy storage component on the system input side, it is the core object of the pre-charging operation in step S101 of this method. The pre-charging operation suppresses the inrush current generated by the capacitive load at the moment of power-on and protects the front-end input device.

[0049] The 48V DC output interface group includes interface J3, interface J4, interface J5, and interface J6, a total of 48V DC output interfaces, all of which are 2-pin industrial-grade terminals, used to supply power to high-power mission payloads (including optoelectronic pods, mapping and sensing equipment, emergency rescue payloads, etc.) of low-altitude aircraft.

[0050] Pin 2 of each interface is connected to the positive terminal of the 48V input bus via an independent controllable power switch, and pin 1 is connected to the system analog ground AGND. Each output branch is equipped with an independent controllable power switch, a branch current sampling circuit, and a branch voltage sampling circuit, which can realize independent on / off control, soft start control, current limiting regulation, and fault isolation of a single branch without interference.

[0051] The DC-DC converter unit's core is the isolated DC-DC power supply module U1, model URF4824QB-100W. This wide-input isolated power supply module is specifically designed for industrial, automotive, and airborne applications. The pin connections and functions are as follows: Pin +Vin (positive input pin): connected to the positive terminal of the 48V input bus, providing DC input to the module; Pin -Vin (negative input pin): connected to the system analog ground AGND; Pin Ctrl (enable control pin): connected to the microcontroller's general-purpose input / output interface, where the microcontroller outputs high and low level signals to control the module's startup and shutdown. This is the core control node for the 24V branch's graded power-on in step S102; Pin +Vo (positive output pin): outputs 24V... The 24V DC input is connected to the positive terminal of the 24V output bus; pin 0V (negative output pin): connected to the system power ground GND; pins Sense+ and Sense- (remote sensing feedback pins): connected to the positive and negative terminals of the 24V output bus respectively, used for remote sampling of the output voltage, compensating for line voltage drop, and improving the output voltage accuracy during long-distance power supply; pin Trim (voltage adjustment pin): used to fine-tune the output voltage value of the module, which can be adjusted by an external resistor; by isolating and converting the 48V DC input to a stable 24V DC output, it provides a suitable power supply for the auxiliary mission payload of low-altitude aircraft. The fully isolated input and output design can prevent the fault on the payload side from being conducted to the input side, improving system safety.

[0052] The 24V output-side energy storage and protection unit includes electrolytic capacitors C3 and C4, and transient suppression diode D2. Electrolytic capacitors C3 and C4 are both high-temperature resistant aluminum electrolytic capacitors with a rated capacity of 220 microfarads and a rated withstand voltage of 50 volts. The positive terminals of capacitors C3 and C4 are connected in parallel to the positive terminal of the 24V output bus, and the negative terminals of capacitors C3 and C4 are connected in parallel to the system power ground GND. The function is to smooth the ripple of the 24V output voltage, provide energy storage support for the 24V branch, suppress the output voltage drop during load changes, and ensure the stability of the load power supply.

[0053] Transient voltage suppressor diode D2 is a bidirectional high-power transient voltage suppressor diode. The negative terminal of the diode is connected to the positive terminal of the 24V output bus, and the positive terminal is connected to the system power ground GND. Its function is to clamp the instantaneous voltage spikes in the 24V output circuit and suppress the instantaneous overvoltage caused by load insertion / removal, electrostatic discharge, and load sudden changes. In conjunction with the software active surge suppression logic of this method, it forms a dual protection system of "hardware passive protection + software active suppression", which greatly improves the surge protection capability.

[0054] The output status indicator unit consists of a current-limiting resistor R1 and a light-emitting diode D1, as detailed below: Current-limiting resistor R1: A surface-mount resistor with a rated resistance of 10 kΩ, one end of which is connected to the positive terminal of the 24V output bus, and the other end is connected to the positive terminal of the light-emitting diode D1; Light-emitting diode D1: A green light-emitting diode, with its negative terminal connected to the system power ground GND. When the 24V output bus is outputting the rated voltage normally, the current is limited by the current limiting resistor R1, which lights up the LED D1, which can intuitively indicate the working status of the 24V power supply circuit, facilitating ground equipment debugging and visual monitoring of the status during flight.

[0055] The 24V DC output interface group includes interfaces J7, J8, J9, J10, and J11, totaling five independent 24V DC output interfaces. All interfaces are 2-pin industrial-grade terminals and are used to power auxiliary mission payloads of low-altitude aircraft (including communication relay equipment, navigation sensors, lighting equipment, flight control auxiliary modules, etc.).

[0056] Pin 2 of each interface is connected to the positive terminal of the 24V output bus via an independent controllable power switch, and pin 1 is connected to the system power ground GND. Each output branch is equipped with an independent controllable power switch, a branch current sampling circuit, and a branch voltage sampling circuit, which can realize independent on / off control, soft start control, current limiting regulation, and fault isolation of a single branch without interference.

[0057] The supporting control and sampling hardware unit is the hardware foundation for implementing all the control logic of this method. The attached figure shows a simplified power main circuit. The detailed description of the supporting control and sampling hardware is as follows: The core controller adopts an automotive-grade microcontroller (MCU), which has multiple ADC sampling channels, multiple PWM output channels and a high-speed communication interface. It can collect sampling data in real time, execute control algorithms, output control signals, and communicate with the aircraft flight control system in real time. The sampling circuit includes one input-side voltage sampling circuit, one input-side current sampling circuit, and independent branch voltage and current sampling circuits for each output branch. All sampling circuits adopt a differential sampling design, which has strong anti-interference capabilities and is suitable for the strong electromagnetic environment of low-altitude aircraft. The output terminals of the sampling circuits are all connected to the ADC sampling pin of the microcontroller to realize real-time acquisition of voltage and current data. The drive circuit and power switch use automotive-grade N-channel MOSFETs for the controllable power switches of each output branch. The drain of the MOSFET is connected to the input bus, the source is connected to the output interface, and the gate is connected to an independent MOSFET drive circuit. The input terminal of the drive circuit is connected to the PWM output pin of the microcontroller. The microcontroller controls the conduction level of the MOSFET by outputting PWM signals with different duty cycles, realizing the on / off control, soft-start voltage regulation, and current limiting regulation of the branch.

[0058] The provided power-on soft start and surge suppression method for low-altitude aircraft mission payloads includes steps S101 to S103. Details are as follows: Step S101. After receiving the power-on command, first perform a pre-charging operation on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches the preset pre-charging completion threshold, thus completing the pre-charging.

[0059] Specifically, the core purpose of this step is to suppress the input surge current at the initial power-on stage, avoiding the capacitive load charging impact of the input-side energy storage capacitors C1 and C2 at the moment of 48V input connection, which could cause the input fuse to blow and the front-end devices to be damaged. At the same time, it avoids the surge current interfering with the power supply stability of the aircraft flight control system. The microcontroller maintains real-time communication with the aircraft flight control system through the CAN bus, and listens for the power-on command sent by the flight control system in real time. When the microcontroller receives a valid power-on command from the flight control system, it does not directly close the main power switch of the main circuit, nor does it allow any output branch power switch to be closed. Instead, it immediately enters the pre-charging working mode, initializes all control parameters, and locks all output branches to the open state.

[0060] This step provides two pre-charging hardware implementation schemes, which can be selected and implemented based on the installation space, power level, and cost requirements of the airborne equipment, including: Option 1: Independent Pre-charge Circuit Solution: In the 48V input main circuit of the system, a main power switch and a pre-charge circuit are set in parallel. The pre-charge circuit consists of a pre-charge MOSFET and a 100-ohm pre-charge current-limiting resistor connected in series. After receiving the power-on command, the microcontroller first closes the pre-charge MOSFET, keeps the main power switch open, limits the charging current through the pre-charge current-limiting resistor, and performs constant current pre-charge operation on the energy storage capacitors C1 and C2 on the input side.

[0061] Option 2: PWM voltage regulation pre-charging scheme: No additional pre-charging circuit is required. Pre-charging is achieved directly through the main power MOSFET of the main circuit. After receiving the power-on command, the microcontroller controls the duty cycle of the main power MOSFET through the PWM pulse width modulation signal, gradually increasing it from an extremely low initial duty cycle. The maximum value of the input current is limited by closed-loop control to achieve constant current pre-charging of the energy storage capacitors C1 and C2, which is suitable for the miniaturization and lightweight design requirements of airborne equipment.

[0062] During the pre-charging process, the microcontroller collects the current value of the input circuit in real time at a fixed sampling frequency of 10 kHz through the input-side current sampling circuit. In this embodiment, the maximum input current threshold during the pre-charging stage is set to 1 Ampere. The microcontroller continuously adjusts the conduction capability of the pre-charging circuit through a proportional-integral (PI) closed-loop control algorithm to stably limit the input current to within 1 Ampere, strictly control the inrush current at the initial power-on stage, and avoid the current from exceeding the rated value of the front-end input device.

[0063] During pre-charging, the microcontroller uses an input-side voltage sampling circuit to collect the voltage value across the energy storage capacitor in real time at a fixed sampling frequency of 10 kHz, which is the voltage value of the 48-volt input bus. In this embodiment, the preset pre-charging completion threshold is set to 95% of the rated 48-volt input voltage, i.e., 45.6 volts. When the voltage value collected by the microcontroller for three consecutive sampling cycles is greater than or equal to 45.6 volts, the pre-charging operation is determined to be complete, and subsequent operations are immediately executed. If the independent pre-charge circuit of Scheme 1 is adopted: immediately disconnect the pre-charge MOSFET, and at the same time close the main power switch of the main circuit to switch the system to the normal power supply mode of the main circuit; If the PWM voltage regulation pre-charge method of Scheme 2 is adopted: immediately increase the PWM duty cycle of the main power MOSFET to 100%, so that the main power MOSFET is fully turned on and enters the normal power supply mode.

[0064] This step sets up the pre-charge timeout fault judgment logic, with a preset maximum pre-charge duration of 5 seconds. If the pre-charge process lasts longer than 5 seconds and the voltage across the energy storage capacitor still has not reached the pre-charge completion threshold, the microcontroller immediately determines it as an input fault or an energy storage capacitor fault and immediately performs the following operations: disconnect all power switching devices, stop the pre-charge operation, and prohibit all subsequent power-on actions; record the time of the fault occurrence, the fault type, and the real-time collected voltage and current data; and send a pre-charge fault alarm signal to the flight control system via the CAN bus to remind the flight control system to execute the corresponding safety handling logic.

[0065] Step S102. After pre-charging is completed, first output multiple 48V DC voltages, then start the DC-DC conversion module to output 24V DC voltage. During the output of 48V DC voltage and 24V DC voltage, a slow start operation is performed to gradually increase the output voltage to the rated operating voltage.

[0066] Specifically, the core purpose of this step is to avoid the superposition of starting currents from multiple branches with different voltage levels simultaneously by using a graded power-on sequence control of "high voltage first, then low voltage, and time-sharing start-up of branches with the same voltage level," combined with the independent soft-start operation of each branch. This significantly reduces the peak current during the power-on process, eliminates the surge impact caused by the simultaneous start-up of multiple branches, and after pre-charging is completed and the main power switch is fully turned on, the 48V input bus voltage has stabilized at the rated operating voltage. The microcontroller strictly follows the following timing logic to perform the power-on operation: keeping the DC-DC converter module U1 in the off state throughout the entire process. In this state, all power switches of the 24V output branches are prohibited from being closed, and the power-on operation of the 48V output branches is prioritized. After all 48V output branches have been started and the output voltage has stabilized at the rated value, the DC-DC converter module U1 is started. After the 24V bus voltage stabilizes, the power-on operation of the 24V output branches is performed. The power-on impact of the 48V and 24V branches is completely isolated in terms of timing to avoid the superposition of the starting current of the two voltage levels. At the same time, branches of the same voltage level are started in a time-sharing manner to avoid the superposition of the starting current of multiple branches of the same voltage level.

[0067] The power-on process is performed through four 48V output branches in a preset fixed sequence. The power-on start interval between adjacent branches is set to 200 milliseconds. That is, after the previous branch is fully started, wait 200 milliseconds before starting the next branch, thus completely eliminating the superposition effect of multiple start-up currents. For the soft start operation of each 48V output branch, the microcontroller sends a start command to the corresponding branch's drive circuit, initializes the PWM duty cycle of the corresponding branch's MOSFET to 0%, and sets the corresponding branch's output voltage to 0V, thus entering the soft start working mode. The microcontroller gradually increases the PWM duty cycle of the corresponding branch's MOSFET according to a preset fixed slope. In this embodiment, the preset fixed slope is an increase of 5% of the duty cycle every 10 milliseconds. As the duty cycle increases, the output voltage of the corresponding branch gradually rises from 0V to the 48V rated operating voltage. During the soft start process, the microcontroller collects the output current value of the corresponding branch in real time at a sampling frequency of 10 kHz through the current sampling circuit of the corresponding branch. In this embodiment, the soft start current limiting threshold of the 48V branch is set to 5 Amps. When the output current value collected by the microcontroller for two consecutive sampling cycles exceeds the preset soft start current limiting threshold, the microcontroller immediately pauses the PWM duty cycle increase operation, keeps the current duty cycle unchanged, and stops the output voltage increase. At the same time, it continues to collect the output current value until the output current value falls back to within the soft start current limiting threshold, and then continues to collect the output current value according to the preset current limiting threshold. The constant slope increases the duty cycle; when the PWM duty cycle of the corresponding branch MOSFET increases to 100%, and the output voltage collected by the microcontroller for 5 consecutive sampling cycles is stable within ±2% of the 48V rated voltage, and the output current is stable within the rated operating range of the corresponding branch, the soft start operation of the branch is determined to be completed, and the branch enters normal operation; after waiting for a preset 200ms time interval, the microcontroller starts the next 48V output branch according to the same process, until all 4 48V output branches have been started and are running stably.

[0068] After all four 48V output branches have started up and are running stably, the microcontroller performs the power-on operation of the 24V branch, including: the microcontroller outputs a high-level enable signal to the Ctrl pin of the DC-to-DC converter module U1, starting the DC-to-DC converter module U1, which converts the 48V input to 24V DC output; the microcontroller collects the voltage value of the 24V bus in real time through the voltage sampling circuit of the 24V bus, and when the 24V bus voltage is stable within ±2% of the rated 24V voltage for a duration of 1 second, the microcontroller will determine the output voltage. At 00 milliseconds, the DC-DC converter module is determined to have completed startup and enters the power-on operation of the 24V output branch; the microcontroller starts the 5 24V output branches sequentially according to the same time-sharing power-on logic as the 48V branch, and the power-on startup interval between two adjacent branches is also set to 200 milliseconds; the soft-start operation of each 24V output branch is completely consistent with the soft-start control logic of the 48V branch, with only parameter adaptation adjustment: in this embodiment, the soft-start current limiting threshold of the 24V branch is set to 3 Amperes to adapt to the power characteristics of the 24V auxiliary load; When the duty cycle of the MOSFET in the corresponding 24V branch increases to 100% and the output voltage stabilizes within ±2% of the rated 24V voltage, the branch is considered to have completed its soft start. After waiting for a preset time interval, the next 24V output branch is started, until all 5 24V output branches have started and are running stably.

[0069] This step provides two alternative power-on sequence optimization schemes, which can be flexibly adjusted according to the actual needs of the flight mission: Option 1: Power-on sorted by power level: The microcontroller pre-stores the rated power parameters of the loads connected to each output branch. When powering on, each branch is started in descending order of rated power. Loads with higher rated power are powered on first, and loads with lower rated power are powered on later. This avoids large fluctuations in bus voltage caused by starting high-power loads later and improves voltage stability during the power-on process.

[0070] Option 2: Power-on according to mission priority: The microcontroller receives mission payload priority information sent by the flight control system. When powering on, it starts each branch in order of priority from high to low. The core payload with high priority is powered on first, and the auxiliary payload with low priority is powered on later, ensuring that the core mission payload is started first, which is suitable for emergency flight missions such as emergency rescue and fire fighting.

[0071] During the soft start-up process of a certain branch, if the corresponding branch experiences overcurrent or undervoltage abnormalities and fails to meet the start-up completion judgment criteria within the preset maximum soft start-up time (set to 2 seconds in this embodiment), the microcontroller immediately performs the following operations: disconnects the power switch of the corresponding branch to stop the soft start-up operation of that branch; records the start-up fault information of the corresponding branch, including fault time, fault type, and real-time voltage and current data; skips the faulty branch and continues to execute the power-on operation of other branches to avoid the start-up of other normal branches being affected by a single branch start-up fault; and sends a start-up fault alarm signal of the corresponding branch to the flight control system via the CAN bus.

[0072] Step S103. During the operation of the 48V DC voltage and 24V DC voltage output, the load current of each branch is monitored in real time. When the surge current exceeds the preset threshold, the current limiting adjustment operation is performed to limit the surge current within a safe range. When the input voltage is abnormal or the branch has an overcurrent fault, the output of the corresponding branch is cut off, and the normal power supply of the non-faulty branches is maintained.

[0073] Specifically, the core objective of this step is to achieve active closed-loop suppression of surge currents caused by load changes and load insertion / removal during flight. Simultaneously, through hierarchical fault protection logic, it achieves precise isolation of single-fault branches, preventing a single-branch fault from causing the entire load to fail, thus ensuring the continuous and stable operation of the power supply system during flight. This includes: after all output branches complete soft start-up and enter normal operation mode, the microcontroller enters normal operation monitoring mode to perform real-time sampling and data processing. Specifically, the microcontroller uses a fixed sampling frequency of 10 kHz to collect the output current and output voltage values ​​of each output branch in real time through the sampling circuit of each branch, while simultaneously collecting the input voltage and total input current values ​​of the input bus. For all collected current and voltage data, the microcontroller performs moving average filtering. The moving average filtering window is set to 8 consecutive sampling points. That is, after each sampling, the latest sampled value is stored in the filtering window, while the earliest sampled value in the window is removed. The arithmetic mean of the 8 sampled values ​​in the window is calculated to obtain the real-time load current and real-time voltage values ​​of the corresponding branch. The filtered real-time data is stored in the microcontroller's register as a basis for subsequent surge suppression and fault protection, and is also sent to the flight control system in real time via the CAN bus for monitoring the overall system status of the aircraft.

[0074] This step addresses the continuous surge current caused by load changes and hot-plugging of loads by employing an active closed-loop current limiting regulation method to suppress it. This, combined with the instantaneous spike protection of the hardware TVS diode, forms a dual protection system. Specifically, the microcontroller sets corresponding surge current thresholds and safe current limiting thresholds for branches with different voltage levels: 48V output branch: surge current threshold set to 120% of the corresponding branch's rated operating current, safe current limiting threshold set to 100% of the corresponding branch's rated operating current; 24V output branch: surge current threshold set to 150% of the corresponding branch's rated operating current, safe current limiting threshold set to 100% of the corresponding branch's rated operating current. The surge current is determined when the microcontroller detects that the real-time load current value of a certain branch exceeds the surge current threshold of the corresponding branch for two consecutive sampling cycles. This immediately determines that a surge current has occurred in that branch and triggers a current limiting adjustment operation. The specific implementation of the current limiting adjustment operation is as follows: the microcontroller uses a proportional-integral-derivative (PID) closed-loop control algorithm to gradually reduce the PWM duty cycle of the corresponding branch's MOSFET according to a preset adjustment step size. In this embodiment, the adjustment step size is set to adjust the duty cycle by 2% every 100 microseconds. During the adjustment process, the real-time load current value is continuously collected until it stabilizes within the safe current limiting threshold, at which point the duty cycle reduction operation stops, and the current duty cycle is maintained. The normal state recovery operation continuously monitors the real-time load current value of the corresponding branch through the microcontroller. When the real-time load current value falls back to within the surge current threshold and the duration reaches a stable judgment time of 200 milliseconds, the surge current is determined to have disappeared. The microcontroller gradually increases the conduction duty cycle of the corresponding branch MOSFET according to the preset recovery step size (in this embodiment, it is set to increase the conduction duty cycle by 1% every 1 millisecond) until the conduction duty cycle is restored to 100%, and the output voltage of the corresponding branch is restored to the rated operating voltage, thus completing the entire surge suppression process.

[0075] This step involves executing global protection operations for global faults such as input overvoltage and input undervoltage to prevent damage to the power module and mission payload due to abnormal input voltage. Specifically, the microcontroller presets the normal operating range of the input voltage to 40V to 56V, corresponding to a fluctuation range of ±15% of the rated 48V input voltage, adapting to the voltage variation characteristics of the onboard battery. Input voltage anomaly determination: When the real-time voltage value of the input bus collected by the microcontroller exceeds the preset normal operating range for three consecutive sampling cycles, it is determined to be an input voltage anomaly, including two types of global faults: input overvoltage fault and input undervoltage fault. Protection operation: When an input voltage anomaly occurs, the microcontroller immediately executes a global protection operation, disconnecting the power switching devices of all output branches, and simultaneously outputting a low-level signal to the Ctrl pin of the DC-DC converter module U1 to shut down the module and stop all outputs. At the same time, it records the fault occurrence time, fault type, and fault voltage extreme value, and sends an input voltage anomaly alarm signal to the flight control system via the CAN bus.

[0076] This step provides precise isolation protection for continuous overcurrent and short-circuit faults in a single branch, disconnecting only the faulty branch while maintaining normal power supply to non-faulty branches. This prevents a single branch fault from causing the entire load to fail. Specifically, a microcontroller sets a corresponding overcurrent fault threshold and fault determination time for each branch. The overcurrent fault threshold is set to 150% of the rated operating current of the corresponding branch, and the fault determination time is set to 100 milliseconds. Overcurrent fault determination: when the real-time load current value of a branch continuously exceeds the overcurrent fault threshold of the corresponding branch for a preset time, a fault determination is made. For extended periods, an overcurrent fault is detected in the corresponding branch. Isolation protection operation: When a single branch overcurrent fault occurs, the microcontroller immediately executes precise isolation protection operation, cutting off the power switching devices of the corresponding faulty branch and stopping the output of the corresponding branch. At the same time, it records the fault occurrence time, fault type, and maximum fault current of the corresponding faulty branch, and sends the corresponding branch fault alarm signal to the flight control system via the CAN bus. While cutting off the faulty branch, the microcontroller maintains the normal power supply status of all other non-faulty branches, does not adjust the control parameters of the non-faulty branches, and ensures the normal operation of other mission payloads.

[0077] This step sets up tiered fault recovery logic to improve equipment availability during flight. Specifically: For global input voltage anomalies: when the input voltage returns to the normal operating range and the duration reaches 500 milliseconds, the microcontroller receives a global reset command from the flight control system and re-executes the complete pre-charge and tiered power-on process to restore normal system power supply. For single-branch local faults: after the fault is cleared, the microcontroller receives a branch reset command from the flight control system and re-executes the complete soft-start process for the corresponding faulty branch to restore power supply to that branch without restarting the entire power supply system and without affecting the operation of other normal branches.

[0078] For example, the complete workflow of this application, combined with the actual flight scenario of a low-altitude aircraft, is described in detail as follows: Before the low-altitude aircraft is powered on from the ground, all power switches are in the open state. The aircraft completes the mission payload loading, and the flight control system completes self-test. The flight control system sends a power-on command to the microcontroller of the power supply system. After receiving the command, the microcontroller initiates a pre-charging operation, pre-charging the input-side energy storage capacitors C1 and C2 with a current limiting threshold of 1 ampere until the capacitor voltage reaches 45.6 volts, completing the pre-charging and closing the main power switch. The microcontroller sequentially starts four 48-volt output branches at 200-millisecond intervals. Each branch performs a slow start operation with current limiting protection, gradually increasing the output voltage to the 48-volt rated value. After all branches are running stably, the DC-DC converter module U1 is started. After the 24-volt bus voltage stabilizes, the microcontroller sequentially starts five 24-volt output branches at 200-millisecond intervals. Each of the 24V output branches performs a slow-start operation with current limiting protection. After all branches have started, the system enters normal operation monitoring mode. During takeoff and flight mission, the microcontroller collects the current and voltage data of each branch in real time. When it detects surge current caused by load insertion / removal or sudden load changes, it immediately performs active current limiting adjustment to limit the surge current within a safe range. During flight, if a branch experiences a continuous overcurrent fault, the microcontroller immediately cuts off the output of the faulty branch, maintains normal power supply to the remaining branches, and sends a fault alarm to the flight control system. If a global fault of abnormal input voltage occurs, the microcontroller immediately cuts off all outputs and performs global protection. After the flight mission is completed, the flight control system sends a power-off command to the microcontroller. The microcontroller disconnects all output branches in sequence, first the 24V branch, then the 48V branch, and finally disconnects the main power switch to complete the power-off process.

[0079] In some embodiments, after receiving the power-on command, a pre-charging operation is first performed on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches a preset pre-charging completion threshold, thus completing the pre-charging. This includes: after receiving the power-on command, performing a constant current pre-charging operation on the energy storage capacitor with a first preset current threshold, and collecting the voltage value across the energy storage capacitor in real time; when the voltage value across the energy storage capacitor reaches the first preset voltage threshold, adjusting the current limiting threshold to a second preset current threshold, and continuing to perform the constant current pre-charging operation until the voltage value across the energy storage capacitor reaches the preset pre-charging completion threshold, thus stopping the pre-charging operation; wherein the second preset current threshold is greater than the first preset current threshold, and the first preset voltage threshold is less than the pre-charging completion threshold.

[0080] By adopting a two-stage stepped constant current pre-charge logic, when the capacitor voltage is zero at the beginning of power-on, a low current limiting threshold is used to completely suppress the initial power-on impact; when the capacitor voltage rises to a safe threshold, a high current limiting threshold is used to improve the pre-charge speed, taking into account both power-on safety and pre-charge efficiency, and adapting to the use requirements of rapid start-up of low-altitude aircraft.

[0081] The system is based on a dual 48V redundant input circuit, input-side energy storage capacitor, main power switch circuit, input-side voltage and current sampling circuit, and microcontroller. The power distribution board is equipped with two parallel 220uF / 50V energy storage electrolytic capacitors on the input side. The main circuit is equipped with automotive-grade N-channel MOSFETs as the main power switches. The microcontroller controls the duty cycle of the MOSFETs through PWM signals, and achieves closed-loop constant current control with real-time feedback from the sampling circuit.

[0082] For example, the provided embodiments can be implemented through the following steps: The first step is that after the microcontroller on the power distribution board receives a valid power-on command from the flight control system of the low-altitude aircraft via the CAN bus, it immediately enters the pre-charge working mode, locks the power switches of all output branches to the off state, and sets the initial duty cycle of the main power switch to zero percent to prevent the main circuit from being directly connected.

[0083] In the second step, the microcontroller performs the first stage of pre-charging operation, sets the first preset current threshold to 0.5 amps, and collects the current value of the input circuit in real time through the input-side current sampling circuit at a fixed sampling frequency of 10 kHz. Through the proportional-integral closed-loop control algorithm, it dynamically adjusts the PWM duty cycle of the main power switch to stabilize the input current at 0.5 amps and performs constant current charging on the energy storage capacitor on the input side.

[0084] The third step is the pre-charging process. The microcontroller uses a fixed sampling frequency of 10 kHz to collect the voltage value across the energy storage capacitor in real time through the input side voltage sampling circuit. In this embodiment, the first preset voltage threshold is set to 60% of the rated 48V input voltage, i.e., 28.8 volts. When the voltage value across the energy storage capacitor collected by the microcontroller for three consecutive sampling cycles is greater than or equal to 28.8 volts, the first stage of pre-charging is determined to be completed, and the second stage of pre-charging operation is entered.

[0085] Fourth, the microcontroller performs the second-stage pre-charging operation, adjusting the current limiting threshold to the second preset current threshold. In this embodiment, the second preset current threshold is set to 2 amps, which is greater than the first preset current threshold. The microcontroller continues to use the proportional-integral closed-loop control algorithm to stabilize the input current at 2 amps and continue to perform constant current charging on the energy storage capacitor.

[0086] Fifth, the microcontroller continuously collects the voltage value across the energy storage capacitor. In this embodiment, the preset pre-charge completion threshold is set to 95% of the rated 48V input voltage, i.e., 45.6 volts. When the voltage value collected by the microcontroller for three consecutive sampling cycles is greater than or equal to 45.6 volts, it is determined that the pre-charge operation is completed. The PWM duty cycle of the main power switch is immediately increased to 100%, so that the main power switch is fully turned on. The system enters the normal power supply mode of the main circuit and waits to execute the subsequent graded power-on operation.

[0087] The pre-charge timeout fault judgment logic is set in two stages: the maximum allowable time for the first stage of pre-charge is set to 3 seconds. If the energy storage capacitor voltage does not reach the first preset voltage threshold within 3 seconds, the microcontroller immediately determines that there is an input line fault or a short circuit fault in the energy storage capacitor, stops the pre-charge operation, disconnects all power switches, and sends a pre-charge fault alarm signal to the flight control system. The maximum allowable time for the second stage of pre-charge is set to 2 seconds. If the energy storage capacitor voltage does not reach the pre-charge completion threshold within 2 seconds, the microcontroller immediately determines that there is an input power undervoltage fault, stops the pre-charge operation, and executes the corresponding fault alarm and protection actions.

[0088] By using a two-stage stepped constant current pre-charging method, the problem of peak impact from capacitive loads during the initial power-on period is completely solved. At the same time, the overall pre-charging time is significantly shortened, balancing power-on safety and response speed. This avoids damage to airborne power supply components caused by power-on impacts and improves the service life and reliability of the power distribution board.

[0089] In some embodiments, after the pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-to-DC converter module is started to output 24V DC voltage. This includes: after the pre-charging is completed, each 48V DC voltage output branch is started sequentially at a preset time interval; after each 48V DC voltage output branch is started and the output voltage is stable, the next 48V DC voltage output branch is started; after all 48V DC voltage output branches have stably output the rated voltage, the DC-to-DC converter module is started, and then each 24V DC voltage output branch is started sequentially at a preset time interval.

[0090] By adopting a power-on timing control logic of "high voltage first, then low voltage, and time-sharing progression of the same voltage level", the starting time of each branch is strictly controlled to ensure that the next branch is started only after the previous branch is completely stable. This eliminates the superposition effect of multiple starting currents from the root, significantly reduces the peak current during the power-on process, and avoids surge faults caused by starting impact.

[0091] The power distribution board features four independent 48V output branches, five independent 24V output branches, a DC-DC converter module, an independent controllable power switch and sampling circuit for each branch, and a microcontroller. Each output branch of the power distribution board is equipped with an independent automotive-grade MOSFET as a power switch, which is controlled separately by the microcontroller's independent I / O port and PWM channel. The on / off control of each branch does not interfere with each other.

[0092] For example, the provided embodiments can be implemented through the following steps: In the first step, after the microcontroller completes the pre-charging operation and the main power switch is fully turned on, the 48V input bus voltage stabilizes at the rated operating voltage. The microcontroller keeps the DC-DC converter module in the off state, locks the power switches of all 24V output branches in the open state, and prioritizes the power-on operation of the 48V output branches.

[0093] The second step is that the microcontroller starts each 48V output branch in sequence according to the preset power-on sequence. In this embodiment, the preset power-on sequence is the four 48V output interfaces on the left side of the power distribution board from top to bottom. The power-on start-up time interval between two adjacent branches is set to 200 milliseconds. The start-up process of each 48V output branch is as follows: the microcontroller sends a start signal to the corresponding branch's drive circuit, performs a soft start operation, and waits for the corresponding branch to start and the output voltage to stabilize before waiting for the preset 200 millisecond time interval and then starts the next 48V output branch.

[0094] The third step is to determine the start-up completion criteria for a single 48V output branch: the output voltage of the corresponding branch collected by the microcontroller for 5 consecutive sampling cycles is stable within ±2% of the rated 48V voltage, and the output current is stable within the rated operating current range of the corresponding branch, with no overcurrent or undervoltage abnormalities. In this case, the corresponding branch is determined to have started up successfully.

[0095] Fourth, the microcontroller completes the startup operation of all four 48V output branches. After all 48V branches are running stably, it outputs a high-level signal to the enable pin of the DC-DC converter module to start the DC-DC converter module. The microcontroller collects the voltage value of the 24V bus in real time. When the 24V bus voltage is stable within ±2% of the rated 24V voltage and the duration reaches 100 milliseconds, it determines that the DC-DC converter module has started up and enters the power-on operation of the 24V output branches.

[0096] Fifth, the microcontroller sequentially starts the five 24V output branches on the right side of the power distribution board according to the same time-sharing power-on logic as the 48V branch. The power-on start-up time interval between two adjacent branches is also set to 200 milliseconds. The start-up process and start-up completion judgment criteria of each 24V output branch are completely consistent with those of the 48V output branch, except that the rated voltage parameter is replaced with 24V.

[0097] Two alternative power-on sequence settings are provided to flexibly adjust the power supply according to flight mission requirements: The first is power-on by power level: the microcontroller pre-stores the rated power parameters of the mission payloads connected to each output branch of the power distribution board. During power-on, each branch is started sequentially in descending order of rated power, with loads with higher rated power energized first and loads with lower rated power energized later, avoiding bus voltage fluctuations caused by starting high-power loads later. The second is power-on by mission priority: the microcontroller receives mission payload priority information from the flight control system. During power-on, each branch is started sequentially in descending order of priority, with core payloads (high priority) energized first and auxiliary payloads (low priority) energized later, ensuring that core mission payloads are started first, adapting to emergency flight mission requirements.

[0098] If an overcurrent or undervoltage abnormality occurs in a branch during startup, and the startup completion judgment standard cannot be reached within the preset maximum slow startup time of 2 seconds, the microcontroller immediately cuts off the power switch of the corresponding branch, records the startup fault information of the corresponding branch, and skips the faulty branch to continue to perform the power-on operation of other branches. This avoids the startup fault of a single branch affecting the power-on of other normal branches. At the same time, the microcontroller sends a startup fault alarm signal for the corresponding branch to the flight control system.

[0099] Through strict time-sharing and hierarchical power-on sequence control, the starting current of different voltage levels and different branches of the same voltage level is completely isolated, which completely eliminates the surge problem caused by the superposition of multiple starting currents, greatly reduces the current impact on the input power supply during power-on, improves the stability of multiple loads being powered on at the same time, and can flexibly adapt to different load configurations and flight mission requirements.

[0100] In some embodiments, the step of performing a soft-start operation during the output of 48V DC voltage and 24V DC voltage, gradually increasing the output voltage to the rated operating voltage, includes: during the startup process of each DC voltage output branch, gradually increasing the output voltage of the corresponding branch according to a preset fixed slope, and collecting the output voltage value and output current value of the corresponding branch in real time; when the output current value exceeds the preset soft-start current limiting threshold, pausing the output voltage increase operation, and continuing to increase the output voltage according to the preset slope after the output current value falls back to within the soft-start current limiting threshold, until the output voltage reaches the rated operating voltage.

[0101] By adding real-time current limiting closed-loop protection logic to the fixed-slope gradual voltage rise, the output current of the branch is monitored in real time while the output voltage rises smoothly. When the output current exceeds the current limiting threshold, the voltage rise is immediately paused and the voltage rise is resumed after the current drops. This ensures the smoothness of the slow start and avoids the risk of overcurrent damage during the start-up process.

[0102] This is achieved by using an independent power switching MOSFET for each output branch of the power distribution board, a branch voltage and current sampling circuit, and a PWM output channel of the microcontroller. The microcontroller controls the conduction level of the corresponding branch MOSFET by outputting PWM signals with different duty cycles, thereby achieving linear adjustment of the output voltage. At the same time, the sampling circuit collects the voltage and current data of the branch in real time to achieve closed-loop control.

[0103] For example, the provided embodiments can be implemented through the following steps: The first step is that after the microcontroller sends a start command to the corresponding branch, it enters the soft start working mode, initializes the PWM duty cycle of the corresponding branch MOSFET to zero percent, and the output voltage of the corresponding branch is 0 volts.

[0104] The second step is that the microcontroller gradually increases the PWM duty cycle of the corresponding branch MOSFET according to a preset fixed slope. In this embodiment, the preset fixed slope is to increase the duty cycle by 5% every 10 milliseconds. As the duty cycle increases, the output voltage of the corresponding branch gradually rises from 0 volts to the rated operating voltage.

[0105] The third step is the soft start process. During the soft start, the microcontroller collects the output voltage and output current values ​​of the corresponding branch in real time at a sampling frequency of 10 kHz. It sets the corresponding soft start current limiting threshold for different types of branches: the soft start current limiting threshold for the 48V output branch is set to 5 Amps, and the soft start current limiting threshold for the 24V output branch is set to 3 Amps.

[0106] Fourth, when the output current value of the corresponding branch collected by the microcontroller for two consecutive sampling cycles exceeds the preset soft-start current limiting threshold, the PWM duty cycle increase operation is immediately paused, the current duty cycle is kept unchanged, and the output voltage rise is stopped; at the same time, the output current value is continuously collected until the output current value falls back to within the soft-start current limiting threshold, and then the duty cycle is gradually increased according to the preset fixed slope.

[0107] Fifth step: When the PWM duty cycle of the corresponding branch MOSFET increases to 100%, and the output voltage collected by the microcontroller for 5 consecutive sampling cycles is stable within ±2% of the rated operating voltage, and the output current is stable within the rated operating range, it is determined that the soft start operation of the corresponding branch is completed, and the soft start mode is exited and the normal operation mode is entered.

[0108] If, during the soft start process, the output current value continuously exceeds the soft start current limiting threshold for a period of 500 milliseconds (the preset maximum current limiting duration), the microcontroller immediately determines that a short circuit or severe overload fault has occurred in the corresponding branch, immediately cuts off the power switch of the corresponding branch, stops the soft start operation, and simultaneously sends a soft start fault alarm signal for the corresponding branch to the flight control system.

[0109] By implementing soft-start control with current-limiting closed-loop protection, the output voltage is smoothly increased, suppressing the inrush current during branch startup. Real-time current-limiting protection also prevents overcurrent damage caused by load short circuits and overloads during startup, significantly improving the safety and reliability of branch startup and adapting to the complex load conditions of low-altitude aircraft.

[0110] In some embodiments, the real-time detection of the load current of each branch during the operation of the 48V DC voltage and 24V DC voltage output includes: continuously sampling the output current of each branch at a fixed sampling frequency during the normal operation of each DC voltage output branch; performing sliding filtering on the multiple continuously collected current sampling values ​​to obtain the real-time load current value of the corresponding branch; and synchronously sampling and filtering the input voltage of each branch to obtain the real-time input voltage value of the corresponding branch.

[0111] By employing fixed-frequency continuous sampling combined with moving average filtering, and simultaneously sampling the current and voltage of each branch, sampling timing deviations are eliminated, significantly improving the accuracy and anti-interference capability of the sampling data. This provides a reliable basis for subsequent surge suppression and fault protection, avoiding misjudgments and malfunctions caused by sampling errors.

[0112] The system is based on a multi-channel synchronous sampling analog-to-digital converter built into the power distribution board, an independent differential sampling circuit for each branch, and a microcontroller. The analog-to-digital converter has a sampling accuracy of more than 12 bits and can simultaneously sample the analog signals of all channels. The differential sampling circuit can effectively suppress common-mode interference and is suitable for the strong electromagnetic environment of low-altitude aircraft.

[0113] For example, the provided embodiments can be implemented through the following steps: The first step is to start the multi-channel synchronous sampling analog-to-digital converter after all output branches have completed the soft start and entered the normal operation mode. The microcontroller starts the multi-channel synchronous sampling analog-to-digital converter and sets the fixed sampling frequency to 10 kHz, that is, to complete the synchronous sampling operation of the entire channel once every 100 microseconds, so as to ensure that the current sampling and voltage sampling of each branch are the values ​​at the same time and eliminate the sampling timing deviation.

[0114] The second step is for the microcontroller to perform continuous sampling and sliding filtering on the output current of each branch. The specific process is as follows: the length of the sliding filtering window is set to 8 consecutive sampling points. That is, after each sampling, the latest current sampling value is stored in the filtering window, and the earliest sampling value in the window is removed. The arithmetic average of the 8 sampling values ​​in the window is calculated, and the average value is the real-time load current value of the corresponding branch.

[0115] The third step is that the microcontroller performs continuous sampling and sliding filtering on the input voltage of each branch, which is synchronized with the current sampling. The sampling frequency and the length of the sliding filtering window are exactly the same as the current sampling. The arithmetic mean of the 8 voltage sampling values ​​in the window is calculated, and the average value is the real-time input voltage value of the corresponding branch.

[0116] The fourth step involves the microcontroller storing the real-time load current and input voltage values ​​obtained after each filtering process into the corresponding registers. This provides a real-time and accurate data source for subsequent surge suppression and fault protection judgments. Simultaneously, the data is sent to the flight control system via the CAN bus for monitoring the overall system status of the aircraft.

[0117] For flight scenarios with particularly severe electromagnetic interference, an optimized scheme for amplitude-limited averaging filtering is provided: before moving average filtering, each newly acquired sample value is first subjected to amplitude limiting processing, with a preset maximum allowable sample value jump amplitude. If the difference between the current sample value and the effective value obtained from the previous filtering exceeds the preset maximum jump amplitude, the current sample value is directly discarded, and the previous effective value is used to replace the current sample value before entering the moving average filtering process, further improving the ability to resist pulse interference.

[0118] By using synchronous sampling and moving average filtering, sampling noise and pulse interference in the strong electromagnetic interference environment of low-altitude aircraft are effectively eliminated, significantly improving the accuracy and stability of current and voltage sampling data. At the same time, synchronous sampling eliminates the timing deviation of current and voltage sampling, avoiding surge misjudgment and fault misjudgment caused by asynchronous sampling, and ensuring the reliability of subsequent control logic.

[0119] In some embodiments, when the surge current is detected to exceed a preset threshold, a current limiting adjustment operation is performed to limit the surge current within a safe range. This includes: when the real-time load current value exceeds the preset surge current threshold, immediately performing a current limiting adjustment operation, gradually reducing the output conduction capability of the corresponding branch according to a preset adjustment step size, and limiting the output current of the corresponding branch to within a preset safe current limiting threshold; when the real-time load current value falls back to within the surge current threshold, gradually restoring the output conduction capability of the corresponding branch to maintain the stability of the output voltage.

[0120] This embodiment is a preferred implementation of surge suppression and current limiting regulation operation. Its core is a step-type closed-loop current limiting regulation control, which solves the problem of suppressing continuous surge current caused by sudden load changes and load insertion / removal. It includes: This is achieved by using an independent power switching MOSFET for each branch of the power distribution board, a synchronous sampling circuit, and a PID closed-loop control unit of the microcontroller. The microcontroller dynamically adjusts the duty cycle of the MOSFET through a proportional-integral-derivative closed-loop control algorithm to achieve precise closed-loop control of the branch output current.

[0121] For example, the provided embodiments can be implemented through the following steps: The first step is for the microcontroller to set corresponding surge current thresholds and safety current limiting thresholds for each branch of the power distribution board. Specifically, the surge current threshold for the 48V output branch is set to 120% of the rated operating current of the corresponding branch, and the safety current limiting threshold is set to 100% of the rated operating current of the corresponding branch. The surge current threshold for the 24V output branch is set to 150% of the rated operating current of the corresponding branch, and the safety current limiting threshold is set to 100% of the rated operating current of the corresponding branch.

[0122] The second step is for the microcontroller to acquire the real-time load current value of each branch in real time. When the real-time load current value of a branch exceeds the surge current threshold of the corresponding branch for two consecutive sampling cycles, the microcontroller immediately determines that a surge current has occurred in the corresponding branch and triggers the current limiting adjustment operation.

[0123] The third step is for the microcontroller to perform current limiting adjustment. Using a proportional-integral-derivative closed-loop control algorithm, the microcontroller gradually reduces the PWM duty cycle of the corresponding branch MOSFET according to a preset adjustment step size. In this embodiment, the adjustment step size is set to adjust the duty cycle by 2% every 100 microseconds. During the adjustment process, the real-time load current value is continuously collected until the real-time load current value stabilizes within the safe current limiting threshold. Then, the duty cycle reduction operation is stopped, and the current duty cycle is maintained.

[0124] The fourth step is for the microcontroller to continuously monitor the real-time load current value of the corresponding branch. When the real-time load current value falls back to within the surge current threshold and the duration reaches the preset 200-millisecond stabilization determination time, the surge current is determined to have disappeared, and a recovery operation is performed.

[0125] The fifth step is for the microcontroller to perform a recovery operation. According to the preset recovery step size, the PWM duty cycle of the corresponding branch MOSFET is gradually increased. In this embodiment, the recovery step size is set to increase the duty cycle by 1% every 1 millisecond until the duty cycle is restored to 100%. The output voltage of the corresponding branch is restored to the rated operating voltage, thus completing the entire surge suppression process.

[0126] If, during the current limiting adjustment process, the real-time load current value of the corresponding branch continuously exceeds the safe current limiting threshold for a period of time equal to the preset maximum current limiting duration of 1 second, the microcontroller immediately determines that the corresponding branch has a continuous short circuit or severe overload fault, immediately cuts off the power switch of the corresponding branch, stops the output, and simultaneously sends a fault alarm signal of the corresponding branch to the flight control system.

[0127] By using a step-by-step closed-loop current limiting regulation, active suppression of continuous surge current is achieved. Compared with traditional passive hardware protection, it has a faster response speed, higher current limiting accuracy, and avoids the problem of irreversible damage to devices. At the same time, through a slow recovery operation, it avoids secondary impacts caused by rapid voltage recovery after the surge disappears, ensuring the continuity and stability of the load power supply, and adapting to the working conditions of frequent dynamic load changes during the flight of low-altitude aircraft.

[0128] In some embodiments, the step of cutting off the output of the corresponding branch and maintaining the normal power supply of the non-faulty branches when an abnormal input voltage or an overcurrent fault is detected includes: when the real-time input voltage value exceeds a preset normal voltage range, it is determined that the input voltage is abnormal, and the power supply of all output branches is immediately cut off; when the real-time load current value of a single branch continuously exceeds a preset overcurrent threshold for a preset duration, it is determined that an overcurrent fault has occurred in the corresponding branch, the output of the corresponding faulty branch is immediately cut off, while maintaining the normal power supply of the remaining non-faulty branches, and recording the fault information of the corresponding faulty branch.

[0129] This embodiment employs a hierarchical fault determination logic, strictly distinguishing between global input anomalies and single-branch local faults, and performing differentiated protection operations for different fault types; for global input faults, it performs global power-off protection to prevent the fault from escalating; for single-branch local faults, it performs precise isolation, cutting off only the faulty branch and maintaining normal power supply to the non-faulty branches, significantly improving the redundancy of the power supply system and flight safety.

[0130] The system is based on the input-side sampling circuit of the power distribution board, the independent sampling circuit and power switch of each branch, the fault handling unit of the microcontroller, and the CAN communication interface. The microcontroller can independently control the on / off state of each branch to achieve precise isolation of a single branch. At the same time, it can communicate with the flight control system in real time through the CAN bus to report fault information.

[0131] For example, the provided embodiments can be implemented through the following steps: The first step is to preset the normal operating range of the input voltage for the microcontroller. In this embodiment, the normal operating range is set to 40V to 56V, which corresponds to a fluctuation range of ±15% of the rated 48V input voltage. At the same time, a corresponding overcurrent fault threshold and fault determination time are set for each branch of the power distribution board. The overcurrent fault threshold is set to 150% of the rated operating current of the corresponding branch, and the fault determination time is set to 100 milliseconds.

[0132] The second step is for the microcontroller to monitor the real-time input voltage value of the input bus. When the real-time input voltage value exceeds the preset normal operating range for three consecutive sampling cycles, it is determined that the input voltage is abnormal, including two types of global faults: input overvoltage fault and input undervoltage fault.

[0133] Third, when a global fault of abnormal input voltage occurs, the microcontroller immediately performs a global protection operation, disconnects the power switching devices of all output branches, and outputs a low-level signal to the enable pin of the DC-DC converter module to shut down the module and stop all outputs; at the same time, it records the fault occurrence time, fault type, and fault voltage extreme value, and sends an input voltage abnormality alarm signal to the flight control system through the CAN bus.

[0134] The fourth step is for the microcontroller to monitor the real-time load current value of each branch. When the real-time load current value of a branch exceeds the overcurrent fault threshold of the corresponding branch for a period of time that reaches the preset fault judgment time, it is determined that a local overcurrent fault has occurred in the corresponding branch.

[0135] Fifth, when a single branch overcurrent partial fault occurs, the microcontroller immediately performs precise isolation protection operation, cutting off the power switching devices of the corresponding faulty branch and stopping the output of the corresponding branch; at the same time, it records the fault occurrence time, fault type, and maximum fault current of the corresponding faulty branch, and sends the corresponding branch fault alarm signal to the flight control system via the CAN bus; while cutting off the faulty branch, the microcontroller maintains the normal power supply state of all other non-faulty branches, does not adjust the control parameters of the non-faulty branches, and ensures the normal operation of other mission payloads.

[0136] For global faults caused by abnormal input voltage, when the input voltage returns to the normal operating range and the duration reaches 500 milliseconds, the microcontroller can receive a global reset command from the flight control system and re-execute the complete pre-charge and graded power-on process to restore system power supply. For local faults in a single branch, after the fault is cleared, the microcontroller can receive a branch reset command from the flight control system and re-execute the complete soft-start process for the corresponding faulty branch to restore power supply to the corresponding branch without restarting the entire power supply system, thus improving equipment availability during flight.

[0137] By implementing graded fault diagnosis and differentiated protection operations, the problem of a single branch fault causing the entire load to fail, as in traditional solutions, has been completely solved. While isolating the fault, the continuous power supply to non-faulty loads is guaranteed to the maximum extent, which greatly improves the redundancy of power supply for low-altitude aircraft mission loads and flight safety, making it particularly suitable for long-endurance and long-distance flight mission scenarios.

[0138] In some embodiments, the method further includes: before the low-altitude aircraft performs a flight mission, obtaining the type information and rated parameter information of the currently mounted mission payload, calling the pre-stored historical operation data of the corresponding payload type, using a machine learning model to self-tune the current threshold of the pre-charging operation, the voltage slope of the soft start operation, and the current limiting threshold of the surge suppression, generating control parameters adapted to the current mission payload, and executing the corresponding control parameters during the current power-on process.

[0139] Before a flight mission, based on the type and rated parameters of the currently mounted mission payload, the optimal control parameters are automatically tuned to suit the current payload through a pre-trained machine learning model. This achieves adaptive control with a set of optimal control parameters for each payload, further optimizing the power-on soft start effect and surge suppression capability of different payloads.

[0140] The microcontroller computing unit, aircraft payload management system, CAN communication interface, and onboard storage unit are implemented based on the power distribution board. The microcontroller has a built-in pre-trained machine learning model and historical operation database, and the onboard storage unit is used to store historical operation data and model weight parameters of different types of payloads.

[0141] For example, the provided embodiments can be implemented through the following steps: The first step is that before the low-altitude aircraft performs a flight mission, the aircraft's payload management system completes the identification of the mission payloads. The microcontroller of the power distribution board obtains the type information and rated parameter information of all currently mounted mission payloads from the payload management system via the CAN bus. The type information includes optoelectronic pods, surveying and mapping sensing equipment, communication relay equipment, and emergency rescue payloads. The rated parameter information includes rated operating voltage, rated operating current, rated power, and capacitive load ratio.

[0142] The second step involves the microcontroller accessing the historical operation database within the onboard storage unit. This database stores historical power-on data, surge suppression data, and optimal control parameters for each type of task load, including the optimal values ​​for the pre-charge current threshold, soft-start voltage slope, and surge suppression current limiting threshold for different loads.

[0143] Third, the microcontroller takes the type information and rated parameter information of the currently mounted task load as input features and inputs them into the pre-trained machine learning model. In this embodiment, the machine learning model adopts a pre-trained backpropagation neural network model. The input layer of the model is the type and rated parameter features of the load, and the output layer is the optimal values ​​of the current threshold for pre-charging operation, the voltage slope for soft start operation, and the current limiting threshold for surge suppression.

[0144] Fourth, after the machine learning model outputs the optimal control parameters adapted to the current mission payload, the microcontroller updates the control parameters of the power-on process of this flight mission to the optimal parameters output by the model, and executes the corresponding control parameters during the power-on process.

[0145] Fifth, after the flight mission is completed, the microcontroller will store the power-on data, surge suppression data, and operating status data of the power supply system during the mission into the historical operation database for subsequent iterative optimization of the machine learning model, continuously improving the self-tuning accuracy of the model.

[0146] The backpropagation neural network model is pre-trained on a ground-based host computer. The training dataset consists of operational data of different types of payloads collected during historical flight missions. After training, the model's weight parameters are embedded into the microcontroller on the power distribution board. The airborne microcontroller only performs forward inference operations on the model and does not need to perform training during flight. The duration of a single inference operation is less than 10 milliseconds, which fully meets the real-time requirements of power-on control.

[0147] The machine learning model enables adaptive self-tuning of control parameters, which can automatically match the optimal control parameters for different types and parameters of task loads. This solves the problem that fixed control parameters cannot adapt to all loads and further optimizes the power-on soft start effect and surge suppression capability for different loads. At the same time, through the continuous accumulation of historical data, the model accuracy can be continuously optimized to adapt to more and more load types, making it extremely versatile and adaptable.

[0148] In some embodiments, the method further includes: during the flight of the low-altitude aircraft, receiving mission load action commands sent by the flight control system in real time, predicting the load change trend within a preset time period through a preset load prediction model, adjusting the current limiting threshold and output adjustment parameters of the corresponding branch in advance according to the predicted load change trend, completing the pre-adjustment of control parameters before the load changes abruptly, and suppressing the surge current caused by the load change abruptly.

[0149] The system utilizes a microcontroller based on a power distribution board, a high-speed CAN communication interface with the flight control system, and onboard storage of a load prediction model. The microcontroller maintains a high-speed communication frequency of 100 Hz with the flight control system, enabling it to receive load action commands from the flight control system in real time and quickly perform pre-adjustments of control parameters.

[0150] For example, the provided embodiments can be implemented through the following steps: The first step is that during the flight of the low-altitude aircraft, the microcontroller of the power distribution board maintains real-time high-speed communication with the flight control system, receiving mission payload action commands sent by the flight control system in real time at a communication frequency of 100 Hz. The action commands include payload power-on, payload power-off, payload function activation, and payload power switching. The commands include the execution time of the action, the payload branch corresponding to the action, and the expected power change corresponding to the action.

[0151] The second step is for the microcontroller to take the received task load action command, the current operating status of the corresponding branch, and the current load current value as input features and input them into the preset load prediction model. In this embodiment, the load prediction model adopts a pre-trained long short-term memory network model. The output of the model is the load change trend of the corresponding branch within a preset time period in the future, including the time point of load change, the magnitude of load change, and the expected peak current.

[0152] Third, in this embodiment, the preset prediction time is set to 200 milliseconds. After the model outputs the load change trend within the next 200 milliseconds, the microcontroller adjusts the current limiting threshold and output adjustment parameters of the corresponding branch in advance according to the predicted load change trend: if the predicted load will increase significantly, the duty cycle of the corresponding branch is reduced in advance, and the current limiting threshold is lowered to prepare for current limiting in advance; if the predicted load will decrease significantly, the voltage stability adjustment parameters of the corresponding branch are increased in advance to avoid output voltage overshoot.

[0153] The fourth step is for the microcontroller to pre-adjust all control parameters before the load changes. At the same time as the load changes, the microcontroller executes the pre-adjusted control logic to suppress the surge current caused by the load change from the source and prevent the surge current from exceeding the safety threshold.

[0154] Fifth, after the load change is completed, the microcontroller continuously monitors the operating status of the corresponding branch. Once the output voltage and output current of the branch stabilize, the control parameters are restored to the normal operating set value. At the same time, the actual data and predicted data of this load change are stored in the onboard database for iterative optimization of the load prediction model.

[0155] The load prediction model is pre-trained on the ground host computer. After training, the model is lightweighted and embedded into the microcontroller of the power distribution board. The model's single inference time is less than 10 milliseconds, which fully meets the real-time requirement of 200 milliseconds prediction time, ensuring that the pre-adjustment operation can be completed before load changes.

[0156] By using a load prediction model and feedforward control, surge current suppression is achieved in advance, solving the lag problem of traditional feedback control. This reduces the peak surge current caused by load changes at the source, significantly improving the surge suppression effect. At the same time, it can adapt to load changes in advance, avoiding large fluctuations in output voltage during load changes, and ensuring the power supply stability of the mission payload under dynamic conditions. It is especially suitable for flight missions with frequent payload actions, such as surveying and mapping and emergency rescue.

[0157] In some embodiments, the method further includes: acquiring power-on data, surge suppression data, and fault data of the power supply system during each flight mission; constructing a full lifecycle operation database of the power supply system; training and analyzing the data in the database using a deep learning model to obtain the performance aging trend of the power supply system; and periodically updating the control parameters for pre-charging, soft start-up, and surge suppression according to the performance aging trend to maintain stable operation of the power supply system throughout its entire lifecycle.

[0158] The system utilizes an onboard storage unit, wireless communication module, and microcontroller based on a power distribution board, in conjunction with a ground data processing platform. The onboard storage unit stores operational data throughout the entire lifecycle, while the wireless communication module enables data interaction and parameter distribution between the airborne equipment and the ground data processing platform.

[0159] For example, the provided embodiments can be implemented through the following steps: The first step is for the microcontroller on the power distribution board to collect and record all the operating data of the power supply system in real time during each flight mission. This includes the pre-charging time, peak inrush current, and soft start time during the power-on process, surge suppression data, current limiting adjustment response speed, and the number, type, and time of faults during operation. This process builds a full lifecycle operating database for the power supply system, and the database stores all data in the order of the flight mission time.

[0160] The second step is that after completing a preset number of flight missions (in this embodiment, the preset number is 10 flight missions), the microcontroller transmits the data from the full lifecycle operation database to the ground data processing platform via a wireless communication link. The ground data processing platform has a pre-trained deep learning model built in.

[0161] Third, the ground data processing platform takes the historical operation data in the full life cycle operation database as input and inputs it into the pre-trained deep learning model. In this embodiment, the deep learning model adopts a combination model of one-dimensional convolutional neural network and long short-term memory network. Through time series analysis of historical data, the model extracts the performance change characteristics of power switching devices, energy storage capacitors and power modules in the power supply system, and outputs the performance aging trend of the power supply system, including quantitative data on device on-resistance changes, capacitor value decay and power module conversion efficiency changes.

[0162] The fourth step involves the ground data processing platform optimizing and adjusting the control parameters for pre-charging, soft start, and surge suppression based on the performance aging trend output by the model: adjusting the pre-charging current threshold and pre-charging duration to address capacitor capacitance decay; adjusting the soft start voltage slope and current limiting threshold to address the increase in on-resistance of power switching devices; and adjusting the surge suppression adjustment step size and safe current limiting threshold to address the decrease in power module conversion efficiency, thereby generating optimized control parameters.

[0163] Fifth, the ground data processing platform sends the optimized control parameters to the microcontroller on the power distribution board via a wireless communication link. The microcontroller updates the onboard control parameters to the optimized parameters and executes the updated control parameters in subsequent flight missions.

[0164] The sixth step involves the microcontroller continuously collecting operational data from subsequent flight missions and storing it in the full lifecycle operational database. Every 10 flight missions completed, the data analysis and parameter optimization are repeated to achieve adaptive iteration of control parameters throughout their entire lifecycle.

[0165] If, during a flight mission, the microcontroller detects that the peak power-on inrush current or surge current exceeds the preset warning threshold, it immediately determines that the device performance has significantly aged. After the flight mission is completed, it immediately triggers a full data analysis and parameter optimization, without waiting for 10 flight missions to be completed, to promptly adapt to changes in device performance and ensure system safety.

[0166] By analyzing the full lifecycle operation data through deep learning models, the performance aging trend of power supply system components can be accurately quantified, and control parameters can be adaptively optimized periodically. This solves the problem of reduced power-on and surge suppression effects caused by component aging, and maintains stable operation of the power supply system throughout its entire lifecycle. At the same time, it can predict the performance degradation of components in advance, adjust parameters in advance, avoid failures caused by component aging, and significantly extend the service life and maintenance cycle of airborne power supply systems, adapting to the long-term use needs of commercial operation of low-altitude aircraft.

[0167] Please see Figure 5 As shown, Figure 5 This is a schematic diagram of the power-on soft start and surge suppression system 200 for low-altitude aircraft mission payloads provided in this application embodiment. The power-on soft start and surge suppression system 200 for low-altitude aircraft mission payloads is used to execute the steps of the power-on soft start and surge suppression methods for low-altitude aircraft mission payloads shown in the above embodiments. The power-on soft start and surge suppression system 200 for low-altitude aircraft mission payloads can be a single server or a server cluster, or it can be a terminal, such as a handheld terminal, a laptop computer, a wearable device, or a robot.

[0168] like Figure 5 As shown, the power-on soft start and surge suppression system 200 for low-altitude aircraft mission payloads includes: The instruction receiving unit 201 is used to, upon receiving a power-on instruction, first perform a pre-charging operation on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches a preset pre-charging completion threshold, thereby completing the pre-charging. The voltage boosting unit 202 is used to output multiple 48V DC voltages after precharging, and then start the DC-DC conversion module to output 24V DC voltage. During the output of 48V DC voltage and 24V DC voltage, a soft start operation is performed to gradually increase the output voltage to the rated operating voltage. The power supply maintenance unit 203 is used to monitor the load current of each branch in real time during operation with 48V DC voltage and 24V DC voltage output. When the surge current exceeds the preset threshold, it performs current limiting regulation to limit the surge current within a safe range. When an abnormal input voltage or an overcurrent fault is detected in a branch, it cuts off the output of the corresponding branch and maintains the normal power supply of the non-faulty branches.

[0169] In some embodiments, after receiving the power-on command, a pre-charging operation is first performed on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches a preset pre-charging completion threshold, thus completing the pre-charging. This includes: after receiving the power-on command, performing a constant current pre-charging operation on the energy storage capacitor with a first preset current threshold, and collecting the voltage value across the energy storage capacitor in real time; when the voltage value across the energy storage capacitor reaches the first preset voltage threshold, adjusting the current limiting threshold to a second preset current threshold, and continuing to perform the constant current pre-charging operation until the voltage value across the energy storage capacitor reaches the preset pre-charging completion threshold, thus stopping the pre-charging operation; wherein the second preset current threshold is greater than the first preset current threshold, and the first preset voltage threshold is less than the pre-charging completion threshold.

[0170] In some embodiments, after the pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-to-DC converter module is started to output 24V DC voltage. This includes: after the pre-charging is completed, each 48V DC voltage output branch is started sequentially at a preset time interval; after each 48V DC voltage output branch is started and the output voltage is stable, the next 48V DC voltage output branch is started; after all 48V DC voltage output branches have stably output the rated voltage, the DC-to-DC converter module is started, and then each 24V DC voltage output branch is started sequentially at a preset time interval.

[0171] In some embodiments, the step of performing a soft-start operation during the output of 48V DC voltage and 24V DC voltage, gradually increasing the output voltage to the rated operating voltage, includes: during the startup process of each DC voltage output branch, gradually increasing the output voltage of the corresponding branch according to a preset fixed slope, and collecting the output voltage value and output current value of the corresponding branch in real time; when the output current value exceeds the preset soft-start current limiting threshold, pausing the output voltage increase operation, and continuing to increase the output voltage according to the preset slope after the output current value falls back to within the soft-start current limiting threshold, until the output voltage reaches the rated operating voltage.

[0172] In some embodiments, the real-time detection of the load current of each branch during the operation of the 48V DC voltage and 24V DC voltage output includes: continuously sampling the output current of each branch at a fixed sampling frequency during the normal operation of each DC voltage output branch; performing sliding filtering on the multiple continuously collected current sampling values ​​to obtain the real-time load current value of the corresponding branch; and synchronously sampling and filtering the input voltage of each branch to obtain the real-time input voltage value of the corresponding branch.

[0173] In some embodiments, when the surge current is detected to exceed a preset threshold, a current limiting adjustment operation is performed to limit the surge current within a safe range. This includes: when the real-time load current value exceeds the preset surge current threshold, immediately performing a current limiting adjustment operation, gradually reducing the output conduction capability of the corresponding branch according to a preset adjustment step size, and limiting the output current of the corresponding branch to within a preset safe current limiting threshold; when the real-time load current value falls back to within the surge current threshold, gradually restoring the output conduction capability of the corresponding branch to maintain the stability of the output voltage.

[0174] In some embodiments, the step of cutting off the output of the corresponding branch and maintaining the normal power supply of the non-faulty branches when an abnormal input voltage or an overcurrent fault is detected includes: when the real-time input voltage value exceeds a preset normal voltage range, it is determined that the input voltage is abnormal, and the power supply of all output branches is immediately cut off; when the real-time load current value of a single branch continuously exceeds a preset overcurrent threshold for a preset duration, it is determined that an overcurrent fault has occurred in the corresponding branch, the output of the corresponding faulty branch is immediately cut off, while maintaining the normal power supply of the remaining non-faulty branches, and recording the fault information of the corresponding faulty branch.

[0175] In some embodiments, the method further includes: before the low-altitude aircraft performs a flight mission, obtaining the type information and rated parameter information of the currently mounted mission payload, calling the pre-stored historical operation data of the corresponding payload type, using a machine learning model to self-tune the current threshold of the pre-charging operation, the voltage slope of the soft start operation, and the current limiting threshold of the surge suppression, generating control parameters adapted to the current mission payload, and executing the corresponding control parameters during the current power-on process.

[0176] In some embodiments, the method further includes: during the flight of the low-altitude aircraft, receiving mission load action commands sent by the flight control system in real time, predicting the load change trend within a preset time period through a preset load prediction model, adjusting the current limiting threshold and output adjustment parameters of the corresponding branch in advance according to the predicted load change trend, completing the pre-adjustment of control parameters before the load changes abruptly, and suppressing the surge current caused by the load change abruptly.

[0177] In some embodiments, the method further includes: acquiring power-on data, surge suppression data, and fault data of the power supply system during each flight mission; constructing a full lifecycle operation database of the power supply system; training and analyzing the data in the database using a deep learning model to obtain the performance aging trend of the power supply system; and periodically updating the control parameters for pre-charging, soft start-up, and surge suppression according to the performance aging trend to maintain stable operation of the power supply system throughout its entire lifecycle.

[0178] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the power-on soft start and surge suppression system and its modules for low-altitude aircraft mission payloads described above can be found in the corresponding contents of the various embodiments of the power-on soft start and surge suppression method for low-altitude aircraft mission payloads, and will not be repeated here.

[0179] The aforementioned power-on soft start and surge suppression method for low-altitude aircraft mission payloads can be implemented as a computer program, which can be used in, for example... Figure 5 It runs on the device shown.

[0180] Please see Figure 6 , Figure 6 This is a schematic block diagram of the structure of a low-altitude aircraft provided in an embodiment of this application. The low-altitude aircraft includes a processor, a memory, and a network interface connected via a device bus, wherein the memory may include a storage medium and internal memory.

[0181] The storage medium can store operating devices and computer programs. The computer program includes program instructions that, when executed, cause the processor to perform any power-on soft start and surge suppression method for low-altitude aircraft mission payloads.

[0182] The processor provides computing and control capabilities to support the operation of the entire low-altitude aircraft.

[0183] Internal memory provides an environment for the execution of computer programs in non-volatile storage media. When the computer program is executed by the processor, it enables the processor to perform any power-on soft start and surge suppression method for low-altitude aircraft mission payloads.

[0184] This network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the terminal to which the present application is applied. Specific low-altitude aircraft may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0185] It should be understood that the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among these, a general-purpose processor can be a microprocessor or any conventional processor.

[0186] In one embodiment, the processor is configured to run a computer program stored in memory to perform the following steps: Upon receiving the power-on command, a pre-charging operation is first performed on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches the preset pre-charging completion threshold, thus completing the pre-charging. After pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-DC conversion module is started to output 24V DC voltage. A soft start operation is performed during the output of 48V DC voltage and 24V DC voltage, gradually increasing the output voltage to the rated operating voltage. During operation with 48V DC and 24V DC output, the load current of each branch is monitored in real time. When the surge current exceeds the preset threshold, current limiting adjustment is performed to limit the surge current within a safe range. When an abnormal input voltage or an overcurrent fault is detected in a branch, the output of the corresponding branch is cut off, and the normal power supply to the non-faulty branches is maintained.

[0187] In some embodiments, after receiving the power-on command, a pre-charging operation is first performed on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches a preset pre-charging completion threshold, thus completing the pre-charging. This includes: after receiving the power-on command, performing a constant current pre-charging operation on the energy storage capacitor with a first preset current threshold, and collecting the voltage value across the energy storage capacitor in real time; when the voltage value across the energy storage capacitor reaches the first preset voltage threshold, adjusting the current limiting threshold to a second preset current threshold, and continuing to perform the constant current pre-charging operation until the voltage value across the energy storage capacitor reaches the preset pre-charging completion threshold, thus stopping the pre-charging operation; wherein the second preset current threshold is greater than the first preset current threshold, and the first preset voltage threshold is less than the pre-charging completion threshold.

[0188] In some embodiments, after the pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-to-DC converter module is started to output 24V DC voltage. This includes: after the pre-charging is completed, each 48V DC voltage output branch is started sequentially at a preset time interval; after each 48V DC voltage output branch is started and the output voltage is stable, the next 48V DC voltage output branch is started; after all 48V DC voltage output branches have stably output the rated voltage, the DC-to-DC converter module is started, and then each 24V DC voltage output branch is started sequentially at a preset time interval.

[0189] In some embodiments, the step of performing a soft-start operation during the output of 48V DC voltage and 24V DC voltage, gradually increasing the output voltage to the rated operating voltage, includes: during the startup process of each DC voltage output branch, gradually increasing the output voltage of the corresponding branch according to a preset fixed slope, and collecting the output voltage value and output current value of the corresponding branch in real time; when the output current value exceeds the preset soft-start current limiting threshold, pausing the output voltage increase operation, and continuing to increase the output voltage according to the preset slope after the output current value falls back to within the soft-start current limiting threshold, until the output voltage reaches the rated operating voltage.

[0190] In some embodiments, the real-time detection of the load current of each branch during the operation of the 48V DC voltage and 24V DC voltage output includes: continuously sampling the output current of each branch at a fixed sampling frequency during the normal operation of each DC voltage output branch; performing sliding filtering on the multiple continuously collected current sampling values ​​to obtain the real-time load current value of the corresponding branch; and synchronously sampling and filtering the input voltage of each branch to obtain the real-time input voltage value of the corresponding branch.

[0191] In some embodiments, when the surge current is detected to exceed a preset threshold, a current limiting adjustment operation is performed to limit the surge current within a safe range. This includes: when the real-time load current value exceeds the preset surge current threshold, immediately performing a current limiting adjustment operation, gradually reducing the output conduction capability of the corresponding branch according to a preset adjustment step size, and limiting the output current of the corresponding branch to within a preset safe current limiting threshold; when the real-time load current value falls back to within the surge current threshold, gradually restoring the output conduction capability of the corresponding branch to maintain the stability of the output voltage.

[0192] In some embodiments, the step of cutting off the output of the corresponding branch and maintaining the normal power supply of the non-faulty branches when an abnormal input voltage or an overcurrent fault is detected includes: when the real-time input voltage value exceeds a preset normal voltage range, it is determined that the input voltage is abnormal, and the power supply of all output branches is immediately cut off; when the real-time load current value of a single branch continuously exceeds a preset overcurrent threshold for a preset duration, it is determined that an overcurrent fault has occurred in the corresponding branch, the output of the corresponding faulty branch is immediately cut off, while maintaining the normal power supply of the remaining non-faulty branches, and recording the fault information of the corresponding faulty branch.

[0193] In some embodiments, the method further includes: before the low-altitude aircraft performs a flight mission, obtaining the type information and rated parameter information of the currently mounted mission payload, calling the pre-stored historical operation data of the corresponding payload type, using a machine learning model to self-tune the current threshold of the pre-charging operation, the voltage slope of the soft start operation, and the current limiting threshold of the surge suppression, generating control parameters adapted to the current mission payload, and executing the corresponding control parameters during the current power-on process.

[0194] In some embodiments, the method further includes: during the flight of the low-altitude aircraft, receiving mission load action commands sent by the flight control system in real time, predicting the load change trend within a preset time period through a preset load prediction model, adjusting the current limiting threshold and output adjustment parameters of the corresponding branch in advance according to the predicted load change trend, completing the pre-adjustment of control parameters before the load changes abruptly, and suppressing the surge current caused by the load change abruptly.

[0195] In some embodiments, the method further includes: acquiring power-on data, surge suppression data, and fault data of the power supply system during each flight mission; constructing a full lifecycle operation database of the power supply system; training and analyzing the data in the database using a deep learning model to obtain the performance aging trend of the power supply system; and periodically updating the control parameters for pre-charging, soft start-up, and surge suppression according to the performance aging trend to maintain stable operation of the power supply system throughout its entire lifecycle.

[0196] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to implement the steps of the power-on soft start and surge suppression method for low-altitude aircraft mission payloads provided in any embodiment of this application.

[0197] The computer-readable storage medium can be an internal storage unit of the low-altitude aircraft described in the foregoing embodiments, such as the hard drive or memory of the low-altitude aircraft. Alternatively, the computer-readable storage medium can be an external storage device of the low-altitude aircraft, such as a plug-in hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the low-altitude aircraft.

[0198] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for low altitude aerial vehicle mission payload power-up slow start and surge suppression, applied to a low altitude aerial vehicle, a mission payload power supply system corresponding to the low altitude aerial vehicle is used to receive two 48-volt direct current inputs, and output multiple 48-volt direct current voltages and multiple 24-volt direct current voltages, characterized in that, include: Upon receiving the power-on command, a pre-charging operation is first performed on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches the preset pre-charging completion threshold, thus completing the pre-charging. After pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-DC conversion module is started to output 24V DC voltage. A soft start operation is performed during the output of 48V DC voltage and 24V DC voltage, gradually increasing the output voltage to the rated operating voltage. During operation with 48V DC and 24V DC output, the load current of each branch is monitored in real time. When the surge current exceeds the preset threshold, current limiting adjustment is performed to limit the surge current within a safe range. When an abnormal input voltage or an overcurrent fault is detected in a branch, the output of the corresponding branch is cut off, and the normal power supply to the non-faulty branches is maintained.

2. The method of claim 1, wherein, Upon receiving the power-on command, the system first performs a pre-charging operation on the energy storage capacitor on the input side of the power supply system, continuously limiting the maximum value of the input current until the voltage across the energy storage capacitor reaches a preset pre-charging completion threshold, thus completing the pre-charging process. This includes: Upon receiving the power-on command, a constant current pre-charging operation is first performed on the energy storage capacitor at the first preset current threshold, and the voltage value across the energy storage capacitor is collected in real time. When the voltage across the energy storage capacitor reaches the first preset voltage threshold, the current limiting threshold is adjusted to the second preset current threshold, and the constant current pre-charging operation continues until the voltage across the energy storage capacitor reaches the preset pre-charging completion threshold, at which point the pre-charging operation stops; wherein the second preset current threshold is greater than the first preset current threshold, and the first preset voltage threshold is less than the pre-charging completion threshold.

3. The method of claim 1, wherein, After the pre-charging is completed, multiple 48V DC voltages are output first, and then the DC-to-DC converter module is activated to output 24V DC voltage, including: After pre-charging is completed, each 48V DC output branch is started sequentially according to a preset time interval. After each 48V DC output branch is started and the output voltage is stable, the next 48V DC output branch is started. After all 48V DC output branches have stably output their rated voltage, the DC-to-DC converter module is started, and then each 24V DC output branch is started sequentially according to the preset time interval.

4. The method of claim 1, wherein, The operation of slow start is performed during the output of 48V DC and 24V DC, gradually increasing the output voltage to the rated operating voltage, including: During the startup process of each DC voltage output branch, the output voltage of the corresponding branch is gradually increased according to a preset fixed slope, and the output voltage and output current values ​​of the corresponding branch are collected in real time. When the output current exceeds the preset soft-start current limiting threshold, the output voltage increase operation is paused. After the output current drops back to within the soft-start current limiting threshold, the output voltage continues to increase at the preset slope until the output voltage reaches the rated operating voltage.

5. The method of claim 1, wherein, During operation at 48V DC and 24V DC output voltages, the load current of each branch is monitored in real time, including: During the normal operation of each DC voltage output branch, the output current of each branch is continuously sampled at a fixed sampling frequency. The multiple current sampling values ​​collected are then subjected to sliding filtering to obtain the real-time load current value of the corresponding branch. The input voltage of each branch is synchronously sampled and filtered to obtain the real-time input voltage value of the corresponding branch.

6. The method of claim 5, wherein, When the detected surge current exceeds a preset threshold, a current limiting adjustment operation is performed to limit the surge current within a safe range, including: When the real-time load current value exceeds the preset surge current threshold, the current limiting adjustment operation is immediately executed. The output conduction capability of the corresponding branch is gradually reduced according to the preset adjustment step size, and the output current of the corresponding branch is limited to within the preset safe current limiting threshold. Once the real-time load current value falls below the surge current threshold, the output conduction capability of the corresponding branch is gradually restored to maintain the stability of the output voltage.

7. The method of claim 5, wherein, The step of cutting off the output of the corresponding branch and maintaining normal power supply to non-faulty branches when an abnormal input voltage or overcurrent fault is detected includes: when When the real-time input voltage value exceeds the preset normal voltage range, it is determined that the input voltage is abnormal and the power supply to all output branches is immediately cut off. When the real-time load current value of a single branch continuously exceeds the preset overcurrent threshold for a preset duration, it is determined that an overcurrent fault has occurred in the corresponding branch. The output of the corresponding faulty branch is immediately cut off, while the normal power supply to the other non-faulty branches is maintained, and the fault information of the corresponding faulty branch is recorded.

8. The method of claim 1, wherein, The method further includes: Before a low-altitude aircraft performs a flight mission, it acquires the type and rated parameter information of the currently mounted mission payload, calls up the pre-stored historical operation data of the corresponding payload type, and uses a machine learning model to self-tune the current threshold of the pre-charging operation, the voltage slope of the soft start operation, and the current limiting threshold of the surge suppression, generating control parameters adapted to the current mission payload, and executing the corresponding control parameters during the power-on process.

9. The method of claim 1, wherein, The method further includes: During the flight of the low-altitude aircraft, the system receives mission load action commands from the flight control system in real time. It predicts the load change trend within a preset time period using a pre-set load prediction model. Based on the predicted load change trend, it adjusts the current limiting threshold and output adjustment parameters of the corresponding branch in advance, completing the pre-adjustment of control parameters before the load changes abruptly, thus suppressing the surge current caused by the load change.

10. The method of claim 1, wherein, The method further includes: Acquire power-on data, surge suppression data, and fault data of the power supply system during each flight mission, construct a full lifecycle operation database of the power supply system, and train and analyze the data in the database using a deep learning model to obtain the performance aging trend of the power supply system. The control parameters for pre-charging, soft start, and surge suppression are updated regularly based on performance aging trends to maintain stable operation of the power supply system throughout its entire lifecycle.

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