Performance assessment of wake mitigation strategies

Many control strategies have emerged in the field of wind energy to address wake interaction effects and try to maximize wind farm power production. They rely either on wake redirection or on induction control. While wake redirection is easily performed by yawing the turbine, efficient and practically deployable induction control is not as straightforward. Recent studies paved the way with periodic dynamic induction control (PDIC), a strategy that generates pulsatile patterns in the wake and increases wake remixing. This study aims at further investigating the physics behind PDIC through large eddy simulations at high resolution. Results show the wake shear layer destabilization leading to the pulsatile wake. This paper also presents a comprehensive comparison between greedy control, PDIC and static yaw. It focuses both on power and loads at the scale of a pair of in-line turbines. It shows that PDIC significantly increases fatigue loads and leads to moderate power gains, while properly oriented yaw leads to fatigue load reduction on the upstream turbine and noticeable increase of the power production.