Power managements of a hybrid electric propulsion system powered by solar cells, fuel cells, and batteries for uavs

Abstract

This chapter describes the power management of a UAV hybrid electric propulsion system. Three electric propulsion systems with different power sources, i.e., solar cells, fuel cells, and batteries, are considered. The power sources are designed and constructed to share the same operation voltage range and connect to the power bus without the need for additional converters or controllers. Each power source is modeled in MATLAB/Simulink, and the component models are verified with published data from the manufacturers as well as flight test data. Furthermore, the component models are integrated into one power system. The integrated power system model is used to simulate the electric propulsion system. For fuel cells and batteries, the simulation process is verified via comparison between the simulation results and available UAV flight test results. Subsequently, two types of power control logic are investigated: passive and active. The passive power management simulation shows that the behavior of each power source and its integrated system are adequate for the overall UAV flight envelope. In addition, the active power management simulation demonstrates that active power management yields more efficient power distribution and better system safety than passive power management. Also, power simulation of a hybrid electric power system allows for estimation of the output behavior of the power source. Therefore, it can be a valuable tool for development of a power control logic that ensures efficient power distribution.