摘要
Airborne wind energy systems are an emerging technology to harvest wind energy at higher altitude. Renewable energy is produced by exploiting the aerodynamic lift exerted by a wing tethered to the ground and controlled to fly crosswind paths. System realizations with either on-board or ground-based generation are possible. The focus of this paper is on ground-based generation systems where a two phase cycle is carried out. In the traction phase, power is produced by reeling-out the tether, which is coiled around drums connected to generators; in the retraction phase, the tether is reeled-in after the maximum length has been reached. A new flight controller for the retraction phase, which is straightforward to implement and tune, is proposed and a theoretical analysis and simulation results are presented.