A NOVEL WAKE CONTROL APPROACH FOR POWER GENERATION IMPROVEMENT OF THREE WIND TURBINES IN A WIND FARM

The total power generation of a wind farm is significantly affected by the adverse wake generation of upstream wind turbines on the aerodynamic performance of the downstream wind turbines. This paper aims to provide a novel hybrid wake control strategy to improve the power generation of horizontal-axis wind turbines in a wind-farm layout. A numerical simulation based on the actuator line method with large eddy simulation (ALM-LES) is performed to investigate the airflow around three-dimensional NREL 5MW turbines in a three-by-one layout. The yaw angle (theta) and tilt angle (phi) of the wind turbines are in the range of (-30 degrees < theta < 30 degrees) and (0 < phi < 35 degrees), respectively. Firstly, the combined effects of yaw-control and tilt-control methods on the velocity profile, vorticity generation and turbulent kinetic energy in the wake region of the multiscale wind farm are investigated. Afterwards, the total power generation of the wind farm is compared with previous wake control methods of wind turbines. It was observed that the proposed hybrid wake control method could improve the total power generation by 9.94% compared to the previous wind turbine wake control techniques. The hybrid control strategy can deviate the wake much better than typical single-control methods. An optimization analysis is also provided to find the most appropriate yaw angles and tilt angles of the wind turbines subject to varying wind speeds.