Fatigue loading parameter identification of a wind turbine operating in complex terrain

An analytic tool is introduced for the evaluation of the fatigue loading of a wind turbine operating in complex terrain, from large scale experimental data. The fatigue loading magnitudes quantified by the equivalent load ranges of the different wind turbine components, namely blade, main shaft and tower, are modelled using multiple regression analysis in order to identify the fatigue inducing wind parameters. The set of independent parameters used in the multiple regression describe the deterministic and the stochastic character of the incoming flow. The results of the application of the proposed methodology indicate that wind turbulence structure is the main fatigue causing parameter for all wind turbine components. Furthermore, the fatigue loading in complex terrain is increased and in some cases this increase exceeds 30%, compared with flat terrain operation.