Experimental evaluation of a hybrid electric propulsion system for small UAVs

Abstract

Purpose This paper aims to experimentally evaluate the performance of a parallel hybrid propulsion system for use in small unmanned aerial vehicles (UAVs). Design/methodology/approach The objective is to combine all the individual components of the hybrid electric propulsion system (HEPS) into a modular test bench to characterize the performance of a parallel hybrid propulsion system, and to evaluate a rule-based controller based on the ideal operating line concept for the control of the power plant. Electric motor (EM) designed to supplement the power of the internal combustion engine (ICE) to reduce the overall fuel consumption, with the supervisory controller optimizing ICE torque. Findings The EM was able to supplement the power of the ICE to reduce fuel consumption, and proved the capability of acting as a generator to recharge the batteries drawing from ICE power. Furthermore, the controller showed that it is possible to reduce the fuel consumption with a HEPS when compared to its gasoline counterpart by running simulated representative UAV missions. The findings also highlighted the challenges to build and integrate the HEPS in small UAVs. Originality/value The modularity of the test bench allows each component to be changed to assess its impact on the performance of the system. This allows for further exploration and improvements of the HEPS in a controlled environment.