Sizing and Performance of an Electrically-Augmented Gearbox Concept for Electrified Aircraft Propulsion Applications

In this paper, we consider the design optimization of electrically-augmented gearbox concepts for different electrified aircraft propulsion applications. Two systems are considered: one with two independent electric machines coupled through a separate drive trains to the low-and high-pressure spools of a turbofan engine, the other the Versatile Electrically Augmented Turbine Engine (VEATE) gearbox, including an additional electric machine and coupling of the two shafts through a variable-speed epicyclic gear train. Design of the systems is formulated as a numerical optimization, with different sets of input parameters for different applications of the system, including electrical power boost, power extraction, and turbine electrified energy management (TEEM). The results shows the masses of the designs considered range from 0.97%–3.1% of total engine mass, depending on the application of interest. The results also show the electrical components account for more than half the total system mass, which is most sensitive to efficiency and power density of these components, as well as the maximum power and torque requirements of the system.