On real-time optimization of airborne wind energy generators

Airborne wind energy generators aim to produce renewable energy by means of aerodynamic lift from tethered wings controlled to fly crosswind paths. The problem of optimizing the operation of such a generator in presence of limited information on wind speed and direction is considered, aiming to maximize the average power developed. First, a study of the traction force is presented for a general path parametrization. Then, the results of this analysis are exploited to design an algorithm to maximize the force, hence the power, in real-time. The algorithm uses only the measured traction force on the tether, and it is able to adapt the system´s operation to maximize the average force with uncertain and time-varying wind. Numerical simulations are presented to highlight the effectiveness of the approach.