Aerospace Adaptation Design of Electron Beam Additive High-Voltage Power Supply

1. Introduction
In the aerospace field, electron beam additive manufacturing technology can realize the integrated forming of complex configuration aerospace components (such as engine combustion chambers and fuel tanks). As the core of the electron beam generating device, the high-voltage power supply needs to adapt to the special aerospace working conditions (extreme temperature, strong vibration, space radiation), and at the same time meet the design requirements of lightweight, high reliability, and long service life. The traditional ground-based electron beam high-voltage power supply cannot be directly applied to aerospace scenarios due to its large volume and weak resistance to harsh environments. Therefore, carrying out targeted aerospace adaptation design has important engineering value.
2. Key Points of Core Adaptation Design
(1) Adaptation Design for Extreme Temperature Environment
The operating environment temperature range of aerospace equipment is wide (-55℃~+85℃), and the key components of the high-voltage power supply need to have wide-temperature working capabilities. In terms of component selection, silicon carbide (SiC) devices with resistance to extreme temperatures are used for power semiconductor devices, whose operating temperature range can reach -55℃~+175℃, and they have low switching losses, making them suitable for high-voltage and high-current scenarios; tantalum polymer capacitors are used as filter capacitors. Compared with traditional aluminum electrolytic capacitors, their capacity attenuation rate at low temperatures is reduced to within 5%, and the leakage current at high temperatures is smaller; metal film resistors are used, with a temperature coefficient controlled within ±100ppm/℃ to ensure parameter stability.
In terms of structural thermal design, an integrated heat dissipation structure is adopted, where the power module is directly attached to the metal heat dissipation shell, and the gap is filled with a thermal conductive silicone pad with a high thermal conductivity (≥200W/(m·K)) to improve heat dissipation efficiency; at the same time, a temperature compensation circuit is set inside the power supply. When the ambient temperature changes, the reference voltage and current are automatically adjusted to offset the impact of component parameter drift on the output performance. For example, in a low-temperature environment of -55℃, through the temperature compensation circuit, the output voltage deviation of the high-voltage power supply is controlled within ±0.5%, meeting the requirement of stable electron beam emission.
(2) Adaptation Design for Strong Vibration Environment
During the launch and on-orbit operation of aerospace equipment, the equipment will bear multi-directional and wide-band vibration loads (vibration frequency 20Hz~2000Hz, acceleration up to 20g), so structural optimization is needed to improve the vibration resistance of the high-voltage power supply. Firstly, a modular design is adopted, dividing the power supply into a high-voltage generation unit, a control unit, and a filtering unit. Each module is connected to the shell through a shock absorption bracket (made of nitrile rubber with a damping coefficient of 0.3~0.5) to reduce vibration transmission; secondly, the internal components are reinforced, power devices are fixed with bolts, and leads are made of flexible wires with appropriate lengths reserved to avoid lead breakage caused by vibration; in addition, in the PCB design, reinforcing ribs are added, thick copper foil (thickness ≥35μm) is used to improve the bending resistance of the PCB, and the component layout is optimized to make the center of gravity evenly distributed, reducing the vibration eccentric load.
Through vibration test verification, the high-voltage power supply after this adaptation design has an output voltage ripple coefficient variation of ≤0.2% under the conditions of 20Hz~2000Hz vibration frequency and 20g acceleration, and no loosening or damage of internal components, meeting the aerospace vibration environment requirements.
(3) Adaptation Design for Space Radiation Environment
Space radiation (such as high-energy particles and γ-rays) can cause single event effects (SEU) and total ionizing dose (TID) effects in the components of the high-voltage power supply, affecting the normal operation of the equipment. In terms of radiation resistance design, a dual strategy of "hardware reinforcement + software fault tolerance" is adopted: in terms of hardware, components with a radiation resistance level of TID ≥100krad(Si) and SEU threshold ≥80MeV·cm²/mg are selected, such as radiation-resistant microcontrollers and memories; the PCB is copper-clad and grounded to reduce radiation-induced current; a radiation shielding layer is set at the high-voltage output end, using lead alloy material, and the thickness is determined according to the radiation dose calculation (usually 1mm~2mm).
In terms of software, a cyclic redundancy check (CRC) algorithm is added to the control program to perform real-time verification of key data. When data errors occur due to single event upsets, a data recovery mechanism is automatically triggered; at the same time, a watchdog timer is set. If the program falls into an infinite loop due to radiation interference, the timer can trigger system reset within 100ms to ensure the power supply returns to normal operation.
(4) Lightweight and Miniaturized Design
Aerospace equipment has strict requirements on weight and volume, so the high-voltage power supply needs to be lightweight while ensuring performance. In terms of structural design, an integrated aluminum alloy shell is adopted, which reduces the weight by 30% compared with the traditional sheet metal shell and improves the strength by 20%; the internal circuit layout is optimized, and a three-dimensional stacking design is adopted to arrange large-volume components such as high-voltage transformers and filter inductors vertically, reducing the plane occupied area, and reducing the volume of the power supply by 40% compared with the traditional ground power supply.
In terms of power density improvement, through the optimization of the topology structure, a phase-shifted full-bridge topology is adopted. Compared with the traditional forward topology, the switching loss is reduced by 50%, and the volume of the heat dissipation structure can be reduced under the same power output; at the same time, a high-frequency design is adopted to increase the switching frequency to 100kHz, reducing the volume of the high-voltage transformer core by 60% and further realizing miniaturization.
3. Application Verification and Effects
The aerospace-adapted electron beam additive high-voltage power supply has performed excellently in ground-based simulated aerospace environment tests: after the -55℃~+85℃ temperature cycle test, the output voltage accuracy remains within ±0.3%; after the 20g acceleration vibration test and 100krad(Si) total dose radiation test, the power supply has a fault-free operation time of more than 1000 hours, meeting the long-life requirements of aerospace equipment. At present, this power supply has been applied to an experimental device for electron beam additive manufacturing of aerospace components, successfully realizing the 3D printing of titanium alloy aerospace components, with the dimensional accuracy error of the printed parts ≤0.1mm, and the mechanical performance indicators (tensile strength, elongation) meeting the aerospace component standards.
4. Conclusion
The aerospace adaptation design of the electron beam additive high-voltage power supply solves the application bottleneck of traditional power supplies in aerospace scenarios through the optimization of extreme environment adaptability, lightweight and miniaturized design, and radiation resistance reinforcement. This design scheme provides key equipment support for the development of aerospace electron beam additive manufacturing technology. In the future, the power density and radiation resistance level can be further optimized to adapt to the needs of more complex deep-space exploration missions.