Effect of Coordination on Transient Response of a Hybrid Electric Propulsion System

Abstract

Thanks to its typical limited speeds and altitudes, Urban Air Mobility represents an interesting application for electric and hybrid-electric power systems. In addition, short-range requirements are compatible with the limited performance of today’s batteries, conversely to their current inapplicability for commercial aviation purposes. For the present study, a parallel Hybrid Electric Propulsion System for a coaxial-rotor Air Taxi has been implemented in Simulink and tested on four different sets of operating conditions, with a transient signal as input for the Power Lever Angle command. The goal of this investigation is to analyze the transient behavior of the hybrid-electric propulsion system in question, to underline the role of electric motors in assisting thermal engine during transients, and, in particular, focuses on the benefits deriving from the adoption of a coordination block which adapts torque split between the two power sources on the basis of actual engine response.