Multiobjective coordinated scheduling of energy and flight for hybrid electric unmanned aircraft microgrids

Abstract

A hybrid electric unmanned aircraft (HEUA) uses the aerial thermal engine and energy storage system (ESS)-driven electric motor to meet the load demand, thus can be viewed as a "mobile multienergy microgrid." Conventionally, for a given flight mission, only the energy of an HEUA is optimized while the flight speed is fixed; thus, the overall energy efficiency may be limited. This paper aims to coordinately schedule the energy consumption and the flight speed of an HEUA toward optimal economic and environmental objectives. First, a coordinated optimization model is proposed to coordinately schedule the energy consumption (including the power output of the thermal engine and the ESS) and flight speed (i.e., the true air speed) of an HEUA for simultaneously minimizing the fuel consumption (FC) and polluted gas emission (PGE). Second, a decomposition-based solution method is developed to convert the original nonlinear multiobjective optimization model into a bilevel programming model which can be solved iteratively. Simulation results demonstrate that, compared with the conventional single energy scheduling, the proposed coordinated scheduling method can achieve much better performance in terms of FC and PGE.