Implementation of Advanced Wind Turbine Controllers for Scaled Turbine Testing in a Wind Tunnel

Based on a series of two experimental campaigns testing advanced controllers on a scaled wind turbine operating in a wind tunnel, this contribution describes the overall experimental method, challenges faced, lessons learned, and opportunities for future work. The two campaigns, run in Fall 2018 and Fall 2019, tested unconstrained and constrained optimal blade pitch controllers, respectively, using preview disturbance measurements of the oncoming wind. Specifically, the first study considered an extension to the linear-quadratic regulator to include feedforward action, while the second deployed model predictive control to incorporate actuator constraints into the optimal control problem. The results of the campaigns have already been published in technical conference and journal papers on control systems; however, detail on how the controllers were implemented was not included in those works. We aim to fill that gap with this contribution, which is targeted at the wind energy community. We describe several aspects of the experimental setup, in particular providing details of the software and hardware used for the controller; share insight on several aspects of the procedure that were difficult and how we overcame those challenges; and summarize the key differences between simulation-based studies and physical testing. By doing so, we hope to share what we learned during our experimental campaigns and provide a point of reference for others looking to carry out experiments on scaled wind turbines operating in wind tunnel facilities.