System Identification of a Wind Turbine Array

Individual wind turbines, whether stand alone or in a wind farms, typically operate to maximize their own production without considering the impact of wake effects on nearby turbines. Investigation into wind turbine interaction within a wind farm has the potential to increase total power and reduce structural loads by properly coordinating the individual turbines that comprise the wind farm. To effectively design and analyze such coordinated controllers requires turbine wake models of sufficient accuracy. This paper develops a dynamic model, derived from experiments, to describe the aerodynamic interactions between two model turbines in a wind tunnel. Experiments were conducted in the atmospheric boundary layer wind tunnel at the Saint Anthony Falls Laboratory at the University of Minnesota and were performed by varying the voltage input to the upwind turbine. Particle Image Velocimetry (PIV) and voltage measurements were used to capture the physical evolution of the interactions of the turbines as well as measure the response of the turbines, respectively. A transfer function model relating the upwind turbine input to downwind turbine output was identified from the experimental data. Following a few modifications to the current setup, future work will include performing wind farm control using the dynamic model presented in this paper.