Optimal Energy Management Strategies and Mission Profiles for a generic Hybrid Aircraft

Abstract

The present paper shows the main characteristic of a numerical
simulation tool, developed in the framework of the European H2020
project MAHEPA, to estimate optimal flight performance of a generic
aircraft featuring a Hybrid powertrain. The purpose of the study is to
determine optimal flight trajectories together with optimal power
controls when a powertrain with multi-energy or multi-power sources (as
the case of a generic hybrid one) is considered. For this purpose a
complete new software has been developed, which is composed by three
main parts: a mission performance “analyser” where the system dynamics
of the problem is determined and it solves the aircraft Equation of
Motion; a powertrain simulator that determines the operating conditions
of the powertrain components and it ultimately computes the consumption
of each energy source; a numerical algorithm that optimizes the aircraft
control variables to determine both the optimum flight trajectory and
the power management according to a certain objective functions and a
variety of constraints. Different study cases are discussed when two
existing flying hybrid aircraft are considered: a Hybrid-Electric (HE)
Pipistrel Panthera aircraft and a Fuel-Cell hybrid (FCH) Pipistrel HY4.
Results are presented also depending on the capability to simulate the
entire mission as a whole (Single-Phase approach) as well as through the
distinction of different flight segments as in the case of the
Multi-Phase approach. In addition, two different resolution algorithms
are tested in order to evaluate what are the aspects that might dictate
the selection of the most suitable one.