Preview-based Asymmetric Load Reduction of Wind Turbines

Fatigue loads on wind turbines caused by an asymmetric wind field become an increasing concern when the scale of wind turbines increases. This paper presents a model based predictive approach to reduce asymmetric loads by using Light Detection And Ranging (LIDAR) measurements. The Model Predictive Controller (MPC) developed is based on a model with individual blade pitching to utilize the LIDAR measurements. The MPC must also maintain a given power reference while satisfying a set of actuator constraints. The designed controller was tested on a 5 MW wind turbine in the FAST simulator and compared to the same controller without LIDAR data. The results showed that the MPC with LIDAR was able to reduce the asymmetric loads compared to the MPC without LIDAR while still maintaining the power reference.