MOSFET Selection Strategy and Device Adaptation Handbook for Intercity eVTOL Airbuses (6-Seater Version) with Extreme Efficiency and Reliability Requirements

 With the rapid development of urban air mobility (UAM) and the urgent demand for sustainable transportation, intercity electric Vertical Take-Off and Landing (eVTOL) airbuses have emerged as a transformative solution. The propulsion, power distribution, and auxiliary systems, serving as the "heart and arteries" of the aircraft, require power semiconductors capable of delivering robust, efficient, and ultra-reliable performance under stringent conditions. The selection of Power MOSFETs and IGBTs directly dictates system efficiency, power-to-weight ratio, thermal management, and operational safety. Addressing the critical demands of eVTOLs for high power density, fault tolerance, wide temperature operation, and lightweight design, this article develops a scenario-optimized device selection strategy.

 

 

图1: 城际 eVTOL 空中巴士（6 座版）方案与适用功率器件型号分析推荐VBBD7322与VBP165R20SE与VBM1401与VBM165R15SE与VBMB15R07S与VBP112MI75产品应用拓扑图_en_01_total

 

I. Core Selection Principles and Scenario Adaptation Logic

(A) Core Selection Principles: Multi-Dimensional Co-optimization

Device selection requires a balanced optimization across voltage rating, specific losses, package thermal/weight performance, and mission-critical reliability:

High Voltage & Robustness: For propulsion inverters typically operating from high-voltage DC buses (400V-800V), select devices with a voltage rating exceeding the maximum bus voltage by a significant margin (≥50-100%) to withstand transients, regenerative braking spikes, and ensure safe operation at altitude.

Ultra-Low Loss for Efficiency & Range: Prioritize extremely low conduction (Rds(on)/Vce(sat)) and switching losses (Qg, Coss/Eoff). This maximizes propulsion efficiency, extends flight range, reduces thermal load, and is critical for battery energy utilization.

Package for Power Density & Cooling: Choose packages like TO-247 or advanced low-inductance types that balance high current capability, excellent thermal impedance (RthJC), and compatibility with direct cooling methods (e.g., cold plates). Weight minimization is also a key consideration.

Aerospace-Grade Reliability: Devices must operate flawlessly across a wide temperature range (-55°C to >150°C), withstand high vibration, and offer proven long-term reliability. Parameters like avalanche energy rating and short-circuit withstand capability are crucial.

(B) Scenario Adaptation Logic: Categorization by Flight-Critical Function

Divide applications into three core domains: First, the Main Propulsion Motor Drive (high-power core), requiring highest efficiency and reliability. Second, High-Current Power Distribution & Management (energy routing), requiring very low conduction loss and robust switching. Third, Auxiliary & Redundant System Drives (support & safety), requiring a balance of performance, compactness, and fault tolerance.

II. Detailed Device Selection Scheme by Scenario

(A) Scenario 1: Main Propulsion Motor Drive Inverter (High-Power)

This application demands high voltage (650V+), high continuous and peak current, ultra-low switching loss for high frequency operation, and superb thermal performance.

Recommended Model: VBP165R20SE (N-MOS, 650V, 20A, TO-247)

 

 

图2: 城际 eVTOL 空中巴士（6 座版）方案与适用功率器件型号分析推荐VBBD7322与VBP165R20SE与VBM1401与VBM165R15SE与VBMB15R07S与VBP112MI75产品应用拓扑图_en_02_propulsion

 

Parameter Advantages: Utilizes Super-Junction Deep-Trench technology, achieving a low Rds(on) of 150mΩ at 10V. The 650V rating provides ample margin for 400V bus systems. TO-247 package offers low thermal resistance for effective heat sinking via cold plates.

Adaptation Value: Enables high-efficiency inverter design for propulsion motors. Low switching loss allows higher PWM frequencies, reducing motor audible noise and torque ripple. High voltage rating ensures robustness against bus voltage spikes during dynamic flight maneuvers.

Selection Notes: Operate in multi-phase parallel configurations to achieve required current levels (e.g., 100A+). Requires gate drivers with high current capability (>2A) and robust isolation. Careful layout to minimize power loop inductance is essential.

(B) Scenario 2: High-Current Power Distribution & Solid-State Switching

Manages battery output, connects to essential busbars, and controls high-power ancillary loads (e.g., avionics cooling, de-icing). Requires extremely low conduction loss to minimize voltage drop and heating.

Recommended Model: VBM1401 (N-MOS, 40V, 280A, TO-220)

Parameter Advantages: Features an exceptionally low Rds(on) of 1mΩ at 10V, enabling minimal conduction loss. Very high continuous current rating of 280A handles main power paths. Trench technology ensures fast switching.

Adaptation Value: When used in battery disconnect or main distribution circuits, drastically reduces I²R losses, improving overall system efficiency and thermal management. Can serve as a high-power solid-state relay for heavy auxiliary loads.

Selection Notes: Ensure proper heat sinking as even small Rds(on) leads to significant heat at hundreds of amps. Gate drive must be robust to fully enhance the device and avoid partial turn-on. Implement current sensing and protection circuits.

(C) Scenario 3: Auxiliary Motor & Redundant System Drives

Drives lower-power but critical systems such as flight control actuators, fuel/pump systems (in hybrid models), or backup ventilation. Requires good efficiency, compact solution, and high reliability.

Recommended Model: VBM165R15SE (N-MOS, 650V, 15A, TO-220)

Parameter Advantages: Super-Junction Deep-Trench technology offers a good balance of voltage rating (650V) and Rds(on) (220mΩ). TO-220 package provides a compact form factor with adequate thermal performance for medium-power loads.

Adaptation Value: Suitable for driving 400V-rated motors in auxiliary systems. Provides the necessary voltage robustness for connection to the high-voltage bus while maintaining good efficiency. Can be used in redundant or fail-over circuits due to its reliable performance.

Selection Notes: Ideal for motor drives in the 1-3kW range. Can be paired with smaller gate drivers. Thermal management via PCB copper area or a small heatsink is required for continuous operation.

III. System-Level Design Implementation Points

(A) Drive Circuit Design: Matched to Application

VBP165R20SE: Use isolated, high-current gate driver ICs (e.g., based on SiC/GaN drivers) with negative turn-off capability. Implement active Miller clamp functionality.

VBM1401: Requires a very low-impedance gate drive circuit, possibly with a dedicated driver stage, to ensure rapid and complete switching given its high intrinsic capacitance.

VBM165R15SE: Can be driven by standard industrial gate driver ICs. Include necessary isolation if referenced to different potentials.

(B) Thermal Management Design: Mission-Critical Cooling

VBP165R20SE (Propulsion): Mandatory use of insulated metal substrate (IMS) boards or direct bonding to liquid-cooled cold plates. Monitor junction temperature via NTC or estimator algorithms.

VBM1401 (Distribution): Connect TO-220 tab directly to a large busbar or dedicated heatsink. Thermal interface material (TIM) with high conductivity is critical.

VBM165R15SE (Auxiliary): Adequate PCB copper pour or a small extruded heatsink is sufficient. Ensure airflow in its compartment.

 

 

图3: 城际 eVTOL 空中巴士（6 座版）方案与适用功率器件型号分析推荐VBBD7322与VBP165R20SE与VBM1401与VBM165R15SE与VBMB15R07S与VBP112MI75产品应用拓扑图_en_03_distribution

 

Overall: Implement rigorous thermal derating per aerospace standards. Position devices to leverage any available convective cooling from onboard environmental systems.

(C) EMC, Protection, and Reliability Assurance

EMC Suppression: Utilize low-inductance DC-link capacitors near inverter phases. Add snubbers (RC/RCD) across devices if needed. Implement proper shielding and filtering for all gate drive and sensor wires.

Protection Circuits:

Overcurrent: Fast desaturation detection for IGBTs/VBP165R20SE, shunt resistors with high-bandwidth op-amps for VBM1401.

Overvoltage: TVS diodes or varistors at strategic locations, especially on gate drives and sensitive inputs.

Short-Circuit: Ensure driver ICs have configurable short-circuit protection and fast turn-off capability.

Redundancy: Design critical paths (e.g., power distribution) with parallel MOSFETs or completely redundant channels where applicable.

IV. Scheme Core Value and Optimization Suggestions

(A) Core Value

Maximized Efficiency for Extended Range: Ultra-low-loss devices directly contribute to reduced energy consumption per flight, a paramount metric for eVTOL operation.

High Power Density & Weight Savings: Selection of efficient devices in appropriate packages minimizes heatsink size and weight, contributing to overall aircraft weight reduction.

Enhanced Safety and Reliability: The chosen devices, with their high voltage margins and robust characteristics, form the foundation of a fault-tolerant electrical power system (EPS), essential for airworthiness.

Scalability: The device portfolio supports scaling from 6-seater to larger eVTOL configurations by paralleling or selecting higher-current variants.

(B) Optimization Suggestions

Higher Power Propulsion: For larger motors or higher bus voltages (e.g., 800V), consider the VBP112MI75 (1200V IGBT+FRD) for its very high voltage and current capability, albeit with trade-offs in switching frequency and loss.

Lightweight Integration: For non-isolated, low-voltage auxiliary converters, the VBBD7322 (30V, 16mΩ, DFN8) offers an extremely compact and efficient solution for point-of-load regulation.

Specialized Redundancy: For critical low-power signal or power isolation switches, devices like VBMB15R07S (500V, SJ) provide a good balance of performance and isolation capability in a TO-220F package.

Conclusion

 

 

图4: 城际 eVTOL 空中巴士（6 座版）方案与适用功率器件型号分析推荐VBBD7322与VBP165R20SE与VBM1401与VBM165R15SE与VBMB15R07S与VBP112MI75产品应用拓扑图_en_04_auxiliary

 

The strategic selection of power semiconductors is fundamental to realizing the performance, safety, and commercial viability of intercity eVTOL airbuses. This scenario-based selection strategy, focusing on the main propulsion, power distribution, and auxiliary systems, provides a practical framework for engineers. Future development will naturally evolve towards wider bandgap devices (SiC, GaN) to push the boundaries of efficiency and power density further, enabling the next generation of sustainable urban air transportation.