UC Berkeley

Next generation hybrid electric aircrafts rely on improvements in electric drivetrains. This work explores the advantages of incorporating high-density, high-efficiency dc-dc converters to enable flexible battery configurations, as well as increased dc bus voltages for reduced cable weight. A dc-dc frontend stage with wide operating range also enables a constant (and optimum) inverter input voltage, irrespective of battery state-of-charge, enabling increased inverter efficiency. Practical challenges such as gate drive power delivery, level shifting, commutation loop and converter start-up are addressed in this work to increase overall performance and reduce weight. Finally, this work demonstrates a high-voltage hardware prototype capable of achieving 99.3% peak efficiency and 28.2 kW/kg specific power density.