Aerospace airborne high‑voltage power supplies serve as core power components for military fighters, civil airliners, helicopters, UAVs, launch vehicles, satellites and space stations. They deliver stable high‑voltage bias and drive power for airborne radars, electro‑optical pods, electronic warfare systems, navigation & communication equipment, satellite attitude control systems, space detectors and ignition actuators. Converting power from airborne generators, lithium batteries and solar arrays into regulated high‑voltage DC, their wide temperature adaptability, vibration resistance, reliability, miniaturization, lightweight design and low EMI directly determine flight safety, operational performance, mission effectiveness and overall aerospace success. Aerospace applications impose extreme requirements far beyond conventional industrial standards: 1. Ultra‑wide temperature resilience. Civil aircraft face −55 ℃ at 12,000 m altitude; fighter equipment bays reach +70 ℃ during low‑altitude flight; UAVs operate across −40 ℃ to +60 ℃; launch vehicles and satellites endure −180 ℃ to +125 ℃ with thermal shock rates exceeding 10 ℃/min. Conventional components suffer severe parameter drift, insulation embrittlement and magnetic instability. Power supplies must maintain stable startup and operation from −55 ℃ to +125 ℃, with space‑grade units covering −180 ℃ to +150 ℃, output drift below ±0.5 % across the full range with no irreversible degradation. 2. Extreme mechanical ruggedness. Vehicles experience continuous vibration, random shock, sinusoidal excitation and high acceleration during takeoff, flight, landing, launch and staging. Fighter maneuverability exceeds 9 g; rocket shock reaches 1,000 g across 10 Hz–2,000 Hz, alongside acoustic vibration and thermal vacuum deformation, risking cracked pins, detached solder joints and structural failure. Compliance with GJB 150, GJB 181 and MIL‑STD‑810 is mandatory, enduring 1,000 g shock, 20 g random vibration and 20 g steady acceleration. 3. Ultimate miniaturization, lightweight design and high power density. Every gram increases fuel consumption and launch costs; onboard space is extremely limited. Power density ≥ 300 W/in³ and weight‑to‑power ratio ≤ 0.5 kg/kW are required with highly integrated modular construction. 4. Ultra‑high reliability and long service life. Onboard power failure causes catastrophic accidents; satellites cannot be maintained post‑launch. MTBF ≥ 1×10⁶ hours and space‑grade design life ≥ 15 years are required with comprehensive redundancy and autonomous fault tolerance. 5. Stringent electromagnetic compatibility. Sensitive radar, navigation and communication systems are easily disrupted by switching noise. Designs must satisfy GJB 151B and MIL‑STD‑461 with ultra‑low conducted/radiated interference and strong immunity to complex airborne electromagnetic environments. 6. Wide input tolerance and high efficiency. Generator voltage varies 18–36 V or 270 V ±40 %; solar arrays fluctuate 50–150 % nominal. Input coverage of 50–150 % nominal ensures stable startup under depleted conditions; overall efficiency ≥ 94 % minimizes heat and thermal management burden. 7. Special environmental resilience. High‑altitude low pressure reduces air insulation strength, triggering corona and breakdown; vacuum eliminates convection cooling; space radiation induces component drift; salt fog and mold degrade materials. Designs require low‑pressure insulation reinforcement, vacuum thermal control, radiation hardening and full environmental protection. This methodology establishes a complete framework covering wide‑temperature topology optimization, full‑range performance tuning, vibration hardening, miniaturized integration, aerospace‑grade reliability and special environmental protection. It standardizes high‑voltage power supply design for fighters, airliners, UAVs, launch vehicles, satellites and space stations, supporting domestic core component advancement. Addressing wide temperature extremes, severe mechanical stress, compact sizing and ultra‑long life, the universal architecture adopts full‑bridge LLC resonant soft‑switch topology + modular integration + fully digital wide‑temperature adaptive control, enhanced by mechanical reinforcement, aerospace component grading and multi‑layer reliability engineering. It overcomes traditional limitations of poor thermal resilience, weak vibration tolerance, low density and insufficient reliability. The full‑bridge LLC achieves zero‑voltage switching (ZVS) on primary switches and zero‑current switching (ZCS) on rectifiers across wide input and load ranges, minimizing losses and EMI while remaining stable despite temperature‑induced parameter drift—ideal for aerospace high‑efficiency, low‑noise demands. Modular integration enables extreme compactness and lightweight performance. Eight core design principles are defined: 1. Wide‑temperature optimized LLC topology. Resonant parameters are robustly tuned for −55 ℃ to +125 ℃ with normalized gain 0.8–1.4 and Q factor 0.4–0.8 to maintain inductive operation and stable ZVS/ZCS despite component drift. Switching frequencies of 100–300 kHz for airborne and 50–200 kHz for space applications balance density, loss and thermal stability. Mixed frequency/phase control extends input voltage coverage to 50–150 % nominal. Auxiliary active circuits maintain soft switching at extreme temperatures; SiC MOSFETs minimize thermal drift in switching and conduction losses. 2. Aerospace wide‑temperature component grading. All semiconductors adopt military/space grades supporting −55 ℃ to +125 ℃ (−180 ℃ to +150 ℃ for space use). SiC/GaN wide‑bandgap devices ensure stable high‑temperature performance with junction temperature ≥ 175 ℃. Control ICs, drivers and references feature low temperature drift (< 5 ppm/℃). Passive components eliminate electrolytic capacitors, using ceramic, PPS film and mica types for stable capacitance and low ESR. Precision metal‑foil resistors maintain accuracy; magnetic cores employ low‑loss nanocrystalline alloys with Curie temperature ≥ 300 ℃. High‑Tg polyimide PCBs, aerospace connectors and rugged PEEK/aluminum structures ensure mechanical integrity. All components undergo strict temperature cycling, thermal shock and vibration screening to eliminate early failure. 3. Fully digital wide‑temperature adaptive control. Redundant military‑grade DSP+FPGA monitor ambient, junction, transformer and capacitor temperatures, establishing full‑range drift models to dynamically adjust frequency, compensation, dead time and drive parameters. Output precision exceeds ±0.3 % with optimized soft‑switch efficiency above 94 %. Dual controller redundancy provides seamless 1 ms failover; multi‑level watchdog ensures automatic recovery from system lockup. Integrated 1553B, CAN, RS485 and SpaceWire isolated communication supports telemetry, remote configuration and in‑orbit upgrades. 4. Extreme mechanical vibration hardening. Integrated lightweight aluminum/titanium housings with reinforcing ribs optimize modal frequency to avoid resonance. PCBs are rigidly mounted at intervals ≤ 100 mm; all modules are bolted with anti‑loose fasteners. Heavy components such as transformers are fully potted; solder joints are reinforced with epoxy; cabling is secured with looms. Finite element vibration/shock simulation and full qualification per GJB 150/MIL‑STD‑810 guarantee structural integrity under severe dynamic loads. 5. High density miniaturization and lightweight integration. Elevated switching frequency reduces magnetic component size; planar magnetics integrate resonant and excitation inductances. Hybrid power modules shrink PCB area; multi‑layer stacking and double‑sided placement maximize volumetric efficiency, achieving > 300 W/in³. Low‑density aluminum, titanium and carbon composite structures reduce weight to ≤ 0.5 kg/kW. 6. Aerospace ultra‑high reliability and long life. Strict derating per GJB/Z 35 and ECSS limits voltage stress ≤ 50 %, current ≤ 40 % and temperature ≤ 60 % of ratings. Four‑level redundancy spans component parallelism, dual control circuits, N+1 modularity and full active/standby system hot swap with 1 ms switchover. Fanless long‑life designs eliminate wear parts, achieving ≥ 1×10⁶ hours MTBF and ≥ 15‑year lifespan. FPGA‑based health monitoring tracks real‑time parameters for lifetime prediction and onboard telemetry. 7. Special environmental protection. Low‑pressure insulation enlarges creepage distances and optimizes electric fields with rounded high‑voltage structures; full potting eliminates air gaps to prevent corona at 10 kPa altitude. Vacuum thermal design prioritizes conduction through high‑thermal‑conductivity interfaces with high‑emissivity coatings (ε ≥ 0.85) for radiative cooling. Space radiation hardening employs radiation‑qualified components (> 100 krad(Si) TID, LET ≥ 80 MeV·cm²/mg), triple modular redundancy and localized tungsten shielding. Full sealing achieves IP65 with conformal coating and corrosion protection for salt fog, humidity and mold resistance. 8. Aerospace EMC and safety protection. LLC soft switching reduces dv/dt and di/dt at the source; fully shielded metal enclosures provide ≥ 60 dB attenuation; multi‑stage EMI filters with feedthrough capacitors satisfy GJB 151B/MIL‑STD‑461. Isolated star grounding eliminates loop interference. Comprehensive non‑bypassable hardware protection (< 1 μs response) covers overvoltage, overcurrent, short circuit, overtemperature, arcing and reverse polarity, with hardwired aircraft safety interlocks. Output filtering ensures ripple < 0.1 %, load regulation ±0.2 %, line regulation ±0.1 % and dynamic response < 50 μs for precision radar and navigation feeds. This framework resolves critical weaknesses including poor thermal stability, low vibration tolerance, insufficient density and limited lifespan. Wide‑temperature LLC with SiC maintains efficient soft switching from −55 ℃ to +125 ℃; full mechanical hardening withstands 1,000 g shock; high‑frequency integration delivers extreme compactness; multi‑layer reliability ensures 15‑year operational life. Widely applicable to fighters, airliners, UAVs, launch vehicles, satellites and space stations, it provides core technical support for domestic aerospace high‑voltage power supply localization and performance breakthroughs.