Power Generation for a 2D Tethered Wing Model with a Variable Tether Length

Airborne wind energy systems consist of a lifting body and a tether. Several airborne wind energy systems have been created by others, but the most promising consists of a wing which translates through the air in a crosswind motion. Two computational models of a translating wing system were used to study the dynamics and performance of these systems. The rst model that was examined consists of a rigid connecting arm between a rotating base station and a wing. A study of this model showed that one can increase the power production of the system by changing the wing angle relative to the connecting arm during motion. Using a variable relative wing angle, an average power of 7:7W is generated which is an increase of 30% over the xed wing angle system. A second model was examined which used a exible tether that could change in length. For this system, power is generated as the tether is reeled o a drum at the base station when tether tension is high. The tether tension can be maximized by the optimal usage of the control parameters such as the reel-in and the bridle orientation of the kite-system. A study of this model showed that the system is capable of asymptotically stable periodic motions with a simple controller for tether length. In addition, this simple controller is able to achieve positive power production of 1:05kW in a 10m=s windspeed. The simple model demonstrates the concept that, for these types of systems, it may be possible to generate higher average cycle powersby strategically using energy to quickly accelerate the system at the ends of the stroke