Implementation of a new energy storage system for a high altitude long endurance aircraft
Author: Stefanie Dagner
Year: 2015
Supervisor: Ágúst Valfells
Abstract
In future solar powered high altitude long endurance (HALE) aircrafts shall be used to replace satellites. They could fulfill the same tasks satellites have to fulfill nowadays, just that HALE aircrafts are lighter and cheaper.
In this project a high altitude long endurance aircraft and its energy source are examined. By using solar panels, it collects the energy over the day - for immediate use and to store the surplus in batteries for the night flight. The battery system with just a short lifetime contributes a lot to the endurance of the flight, so there is space for improvement.
After sizing a proper original model, consisting of Lithium-ion batteries as energy storage system, there are introduced several new energy storage models to replace the original model. The total aircraft weight, power demand of the aircraft, designs of the solar cell system and the energy storage system and lifetimes of the different models are determined. After that, a recommendation for a replacement for the original energy storage model is given.
The recommendation is to use a combination of proton exchange membrane fuel cells and super capacitors as energy storage system. The energy storage system consists of 60% of proton exchange membrane fuel cells and 40% of super capacitors. Here the best results for lifetime of the energy storage system as well as the storage system's weight and the total weight of the aircraft are achieved.
Link to publication.