Load Analysis of Look-ahead Collective Pitch Control Using Lidar

Nacelle based LIDAR (Light detection and ranging) systems provide preview information of wind disturbances at various distances in front of a wind turbine. Preliminary work towards this objective [1] has shown that the predictive knowledge of the rotor effective wind speed can be used to improve the speed regulation by a predictive feedforward update to the collective pitch feedback controller, which indicates load reduction of tower and blades. This paper presents a fatigue load analysis to concretize the improvement of look-ahead collective pitch control of a 5MW turbine [2], using realistic LIDAR simulations and comparing the results to the UpWind controller [3]. In this paper the basic idea of the look-ahead controller is presented in Section 2. In Section 3 the optimization of the controller parameter is elaborated and the implementation is described in Section 4. Section 5 shows the results and Section 6 concludes the presented work.