A Comparison of Individual and Collective Pitch Model Predictive Controllers for Wind Turbines

Model predictive control (MPC) has been gaining attention in the wind energy field for its ability to optimize performance while taking into account constraints and preview disturbance measurements such as those that can be provided by lidar scanners. While a growing body of research exists showing the benefits of MPC over baseline controllers, little work has been done to compare competing MPC formulations. This paper compares the performance of collective and individual pitch enabled linear-quadratic MPCs both to each other and to their baseline counterparts. Realistic lidar measurements are used to provide preview information. Our results show that collective pitch MPC can lead to reductions in both rotor speed deviations and tower damage equivalent loads with little increase in pitch activity. Moreover, we find that the individual pitch MPC can reduce blade loads further than a baseline individual pitch controller with less actuation, although as with all individual pitch controllers, there is a significant increase in pitch activity compared to collective pitch controllers.