Integration of a Microtubular Solid Oxide Fuel Cell into a Mini-UAV: Design and Simulation of Power System Architecture 2010-01-1776
Mini UAVs in the ≺20 kg category are widely operated by military
and civilian organizations, usually for surveillance purposes, and
many are electrically powered for low acoustic and infra-red
observability. Despite recent improvements in Lithium Polymer
battery technology, endurance is still usually limited to around 1
hour for fixed wing vehicles. For operational reasons, it is
desirable to increase endurance and fuel cells can provide the high
energy density necessary to do this.
Many examples of PEMFC (Polymer Electrolyte Membrane Fuel
Cell)-powered UAVs have been flown in recent years, all relying on
a supply of hydrogen on board the UAV, giving the usual safety and
weight concerns surrounding hydrogen storage. Solid oxide fuel
cells (SOFCs) operate at a sufficiently high temperature to allow
some flexibility in fuel source; in particular microtubular solid
oxide fuel cell (mSOFC) stacks have been developed that run on
methane and propane, gases that are easier to store and more
readily available than hydrogen. mSOFC technology also offers the
potential for higher efficiencies than PEMFCs.
Some examples of mSOFC-powered UAVs do exist, but these are
aircraft developed and flown in an R&D context, not operational
vehicles. This project aims to surmount and document the issues
surrounding integration of an mSOFC power system into an existing
UAV used in its operational environment. It also serves to provide
a stimulus for the further development of mSOFC technology, which
shows good potential but currently lags PEMFC technology by a
number of years.
This paper presents initial modeling results from a 3-year
project to integrate a propane-powered microtubular solid oxide
fuel cell power system into an existing (and operational)
electrically powered mini UAV.