Gust load reduction concept in wind turbines

Abstract

AbstractA concept is presented of gust alleviation in wind turbines by using the blade aerodynamic torsional moment as an actuator for forcing the blade to feather in order to reduce aerodynamic loads. The pitching to feather is implemented through a temporary release of the blade‐hub torsional connection after that the blade rotates freely until it reaches the assumed pitch angle. To describe this process, a simple wind turbine model with three elastic blades is formulated and some numerical simulations are performed. The results of the simulations include, among others, the time‐history of the out‐of‐plane blade bending moment in response to the uniform gust, showing that, in this way, it is possible—at least theoretically—to reduce this moment by approximately 2/3 of its peak value. Moreover, the blade pitch angle changes faster than increased by a regular control actuator. Copyright © 2009 John Wiley & Sons, Ltd.