Numerical study of the effect of individual pitch control and yaw dynamics on wind turbines wakes and loads

With the growing number of wind turbines, the interest on how to optimize the power production at the wind farm level is rising. Several techniques have already been identified to be effective, such as wake redirection or wake mitigation. One drawback of such strategies is the increased loads it induces. Control strategies such as Individual Pitch Control (IPC) have shown great potential at reducing the loads. In this Master's Thesis we investigate power optimization strategies based on yaw, along with the effect of combining them with load reducing IPC. The investigations are carried out through numerical simulations with an accurate LES Vortex Particle-Mesh code. The study focuses on the loads, the power output, the wake, and the potential power gain downstream. First, static yaw misalignment to redirect the wake is addressed. Second, a passive dynamic yaw strategy is considered, named free yaw, intended to lead to enhanced wake dissipation. We have observed that IPC has a quite positive impact on static yaw misalignment, while it tends to significantly reduce the wake dissipation effect for the free yaw. Among the different strategies studied, the best one is finally identified for two inline wind turbines.