An important design criterion for large wind turbines is to reduce fatigue and extreme loads on the support structure and blades by control. This is a challenging task, because transients such as gusts represent an unknown disturbance to the control system. Conventional feedback controllers can compensate such excitations only with a delay since the disturbance has to pass the entire wind turbine and actuator dynamics before showing its effects in the controller outputs. This usually results in additional loads for the wind turbine and requires high actuator rates. LIDAR (Light detection and ranging) systems are able to provide preview information of wind disturbances at various distances in front of wind turbines. This information can be used to improve control of wind turbines not only to reduce the loads but also to increase their power output.
Stuttgart Wind Energy (at) Institute of Aircraft Design