Experimental study of using a PEM fuel cell/battery hybrid system to power small UAVs

Abstract

Present fuel cell systems have demonstrated a high degree of efficiency for automotive applications and currently the technology is under consideration for use as the potential power source for Unmanned Aerial Vehicles (UAVs). This paper presents an experimental study that was carried out in order to investigate the performance of the Nexa hybrid system (FC/battery) as the main power source for the PiperCub J3 aircraft. A flight scenario was used to investigate the feasibility of using the Nexa FC/battery hybrid system to satisfy the power requirements of the aircraft, including take-off, climb, cruise, descent and landing. In this study, the electric hybrid system consists of a 1.2kW proton exchange membrane FC, a unidirectional step-down DC/DC converter and two 12V batteries driving an electrical engine. The power delivered to the electrical motor will be from both the FC and battery or from only one of them depending on the power demands. If the battery voltage drops, the FC charges up the batteries at the same time as it delivers power to the motor via converter.