Wind turbine wake control strategies: A review and concept proposal

Abstract A wind farm’s overall power production is significantly less than its nominal power, defined as the sum of the wind turbines’ rated outputs. The primary cause for this significant loss is the exposure of downstream wind turbines to the aerodynamic wake of their upstream counterparts. Wind farm layout optimization aims at minimizing such adverse effects by finding optimal wind turbine positions that are less exposed to the upstream wake. Over the past few years, researchers have extended their fight against adverse wake effects beyond the layout optimization, i.e., the design process, onto the control and operation process. Several active wake control strategies have been proposed and studied to decrease the power loss of downstream wind turbines by steering or weakening the upstream wakes. First, the article reviews these strategies, including yaw control, pitch control, torque control, tilt control, and finally, cone angle control. Then, it proposes a novel wake steering technique where passive stationary vanes redirect the upstream wake. The authors conducted scaled wind tunnel experiments to investigate the performance of the proposed concept. Using a 3D-printed wake deflector between two in-line turbines increased the downstream turbine’s power production by more than 15%, which is significant compared to the existing wake control strategies. The article concludes by comparing the proposed technology’s effectiveness against existing wake control techniques.