Operational Regions of a Multi-Kite AWE System

Abstract

Multiple-kite airborne wind energy systems (MAWES) aim to efficiently harvest the stronger, less-intermittent winds at high altitude without material-intensive towers. Solving a series of optimal control problems for two-kite MAWES, we show that pumping-cycle MAWES have three distinct operational regions: Region I, where power is consumed to stay aloft; Region II, where the power harvesting factor grows until the design wind speed; and Region III, where the power extraction is curtailed so as to respect the physical limitations of the system. The actuator disk (AD) method is arguably the simplest tool to model aerodynamic induction effects, though its validity is limited. In this paper, we show that AD is not valid for Region I.