With the rapid development of urban air mobility (UAM) and cold chain logistics, electric Vertical Take-Off and Landing (eVTOL) aircraft for low-altitude cargo transport present extreme demands on powertrain systems. These systems, acting as the "heart and muscles" of the aircraft, must provide highly efficient, reliable, and lightweight power conversion and motor drive for propulsion, avionics, and cryogenic temperature control units. The selection of power semiconductor devices (MOSFETs/IGBTs) is critical in determining system efficiency, power density, thermal performance, and ultimately, flight safety and mission reliability. Addressing the stringent requirements of eVTOLs for high thrust-to-weight ratio, extended range, operational safety in varied environments, and system robustness, this article develops a practical, scenario-optimized selection strategy.
I. Core Selection Principles and Scenario Adaptation Logic
(A) Core Selection Principles: Multi-Dimensional Co-Design
Device selection requires a holistic approach across key dimensions—voltage rating, switching/conductive loss, package thermal & parasitic characteristics, and aerospace-grade reliability—ensuring perfect matching with harsh operational profiles.
High Voltage Margin & Ruggedness: For high-voltage propulsion buses (e.g., 400V, 800V), prioritize devices with sufficient voltage derating (≥30-50%) to withstand transients, regenerative braking spikes, and altitude-related stress. Avalanche/SCWT ruggedness is crucial.
Ultra-Low Loss for Efficiency & Range: Minimizing total loss (Rds(on)/VCEsat for conduction, Qg/Qrr for switching) is paramount for maximizing battery energy utilization, extending range, and reducing thermal management burden.
Package for Power Density & Cooling: Select packages (e.g., TO247, DFN) offering an optimal balance of high current capability, low thermal resistance (RthJC), and low parasitic inductance. Compatibility with advanced cooling solutions (cold plates, forced air) is essential.
Aerospace-Grade Reliability: Devices must operate reliably across wide temperature ranges (-55°C to 175°C+), withstand high vibration, and offer proven longevity. Focus on parameters like MTTF, HTRB, and Rg immunity.
(B) Scenario Adaptation Logic: Categorization by Powertrain Segment
Divide applications into three core segments: First, High-Power Propulsion Motor Drives (thrust core), requiring very high current, efficiency, and ruggedness. Second, Auxiliary & Cryogenic System Power Control (mission-critical support), requiring medium power, fast switching, and precise control for compressors/peltiers. Third, High-Voltage Distribution & Protection (safety backbone), requiring high-voltage blocking capability and robust isolation.
II. Detailed Device Selection Scheme by Scenario
(A) Scenario 1: High-Power Propulsion Motor Inverter (50kW-200kW per motor) – Thrust Core Device
Propulsion motors demand handling extremely high continuous and peak phase currents with high switching frequency for field-oriented control (FOC), necessitating the lowest possible loss and highest power density.
Recommended Model: VBGP1805 (Single N-MOSFET, 80V, 120A, TO247)
Parameter Advantages: SGT (Shielded Gate Trench) technology achieves an ultra-low Rds(on) of 4.6mΩ at 10V. A continuous current of 120A (with high peak capability) is suitable for high-current phase legs in 400V+ battery systems (using multi-level topologies or paralleling). The TO247 package offers excellent thermal interface for heatsinking.
Adaptation Value: Drastically reduces conduction loss in inverter bridges. For a 100kW motor at 400V DC, phase current ~180A RMS, using paralleled devices can keep conduction losses minimal, pushing inverter efficiency above 98.5%. High current capability supports high torque demands during take-off and climb.
Selection Notes: Must be used in parallel configurations for high-power motors. Careful attention to dynamic current sharing via matched Rg and layout symmetry is required. Requires direct liquid cooling or high-performance heatsinks. Must be paired with rugged, high-speed gate drivers with desaturation protection.
(B) Scenario 2: Cryogenic System & Auxiliary Load Controller (1kW-10kW) – Mission Support Device
Thermoelectric coolers (Peltiers), compressor drivers, and avionics DC-DC converters require efficient switching, compact size, and reliability for continuous temperature management.
Recommended Model: VBN1202M (Single N-MOSFET, 200V, 10A, TO262)
Parameter Advantages: 200V rating provides ample margin for 48V or 100V auxiliary buses. A low Rds(on) of 250mΩ at 10V ensures low conduction loss. The TO262 package offers a good balance of power handling and footprint. A moderate Vth of 3V provides good noise immunity.
Adaptation Value: Ideal for the high-side/low-side switches in half/full-bridge DC-DC converters powering Peltier modules or compressor motor drives. Enables high-frequency PWM (50-100kHz) for precise temperature control, crucial for cargo integrity. Its voltage rating also suits active clamp or snubber circuits in auxiliary power supplies.
Selection Notes: Ensure switching frequency is optimized to balance loss and control bandwidth. Requires a dedicated gate driver. Implement local decoupling and thermal vias under the package. Consider paralleling for higher current auxiliary loads like hydraulic pumps.
(C) Scenario 3: High-Voltage Distribution & Protection Switching (800V System) – Safety Backbone Device
Battery disconnect units (BDU), pre-charge circuits, and high-voltage DC link protection require devices capable of blocking system voltage reliably and handling inrush/ short-circuit events.
Recommended Model: VBMB17R15S (Single N-MOSFET, 700V, 15A, TO220F)
Parameter Advantages: Super-Junction (SJ) Multi-EPI technology provides a high 700V VDS rating with a relatively low Rds(on) of 340mΩ. The 15A continuous current is suitable for distribution paths. The TO220F (fully isolated) package simplifies heatsinking and improves isolation safety.
Adaptation Value: Provides a robust and efficient solution for solid-state power switching in the BDU, replacing bulky contactors. Its fast switching allows for active pre-charge control. The high voltage rating is essential for 800V architecture reliability, providing buffer against voltage surges.
Selection Notes: Typically operates in hard-switched, low-frequency on/off mode. Focus on avalanche energy rating for fault conditions. Must be driven by an isolated gate driver with sufficient voltage offset. Incorporate comprehensive overcurrent and overtemperature sensing.
III. System-Level Design Implementation Points
(A) Drive Circuit Design: Matching High-dv/dt Environment
VBGP1805: Pair with high-current, high-speed gate drivers (e.g., isolated IGBT drivers) featuring strong pull-up/pull-down (≥4A). Use Kelvin source connection for stability. Implement active miller clamp and desaturation detection.
VBN1202M: Use optimized medium-power gate drivers. Attention to loop inductance minimization is key for fast switching in DC-DC stages.
VBMB17R15S: Use reinforced isolated gate drivers rated for full system voltage. Include robust RC snubbers across drain-source to manage voltage ringing during switching.
(B) Thermal Management Design: Mission-Critical Cooling
VBGP1805 (Propulsion): Implement direct liquid cooling cold plates attached to the baseplate. Use thermal interface materials (TIM) with high conductivity. Monitor junction temperature via NTC or model-based estimators.
VBN1202M (Auxiliary): Mount on a dedicated PCB heatsink with forced air cooling from cabin/avionics airflow. Ensure sufficient copper area and thermal vias.
VBMB17R15S (HV Distribution): Mount on a main chassis-cooled heatsink. Leverage the isolated package for easier thermal mounting.
(C) EMC & Reliability Assurance for Airborne Systems
EMC Suppression: Implement strict PCB zoning (high-power, low-power, sensitive). Use common-mode chokes on all motor phases and DC input. Add RC snubbers across all high-speed switches. Shield all critical signal lines.
Reliability Protection:
Derating: Apply stringent derating rules (e.g., voltage ≤70%, current ≤60% at max junction temperature).
Fault Protection: Implement redundant current sensing (shunt + Hall), hardware desaturation trip, and software overcurrent limits. Use drivers with integrated fault reporting.
Environmental Hardening: Conformal coat PCBs. Select components rated for the required temperature and vibration profiles. Add TVS diodes and varistors at all external interfaces and power inputs.
IV. Scheme Core Value and Optimization Suggestions
(A) Core Value
Maximized Powertrain Efficiency & Range: Ultra-low loss devices directly contribute to higher overall system efficiency, reducing battery drain and enabling longer payload range.
Enhanced Power Density & Weight Savings: Selection of high-performance SGT and SJ devices in optimal packages reduces the size and weight of the power electronics bay, crucial for eVTOL payload capacity.
Aerospace-Oriented Reliability: The chosen devices, with robust packages and ratings, form a foundation for building systems that meet the rigorous reliability and safety standards of aviation.
(B) Optimization Suggestions
Higher Power Propulsion: For higher voltage (>800V) or power levels, consider VBMB18R07S (800V, 7A, SJ) for breakdown margin or evaluate IGBTs like VBP16I20 (650V, 20A, FS-IGBT) for very high power, lower frequency inverters where conduction loss dominates.
Integration & Sensing: For auxiliary systems, consider dual MOSFETs like VBK362KS (Dual-N, 60V) for compact half-bridge designs. For current monitoring, look for variants with integrated sense FETs.
Low-Voltage High-Current: For very high current 48V distribution or motor drives, VBGQA1810 (80V, 58A, DFN8) offers exceptional power density in a small footprint.
Specialized Functions: Use VBF2317 (P-MOS, -30V, -40A) for specific high-side switch applications where simplified drive is needed in lower voltage auxiliary rails.
Conclusion
The strategic selection of power semiconductor devices is pivotal to realizing the demanding performance, reliability, and safety targets of cryogenic cargo eVTOL powertrains. This scenario-based methodology, focusing on the propulsion core, mission support systems, and high-voltage safety backbone, provides a clear framework for optimized design. Future development will involve the adoption of Wide Bandgap (SiC, GaN) devices for the highest efficiency segments and the integration of functionalities into Intelligent Power Modules (IPMs), further advancing the frontier of electric aviation for sustainable logistics.

Detailed Topology Diagrams