Active and Passive Methods for Load alleviation in Wind Turbines

Introduction and Motivation •Increasing wind turbine size •Increasing blade mass •Increasing blade root loads •Further blade increase limited by loads Introduction Sources of loads •Blade mass induced loads (1 perrevolution) •Wind velocity profile •Wind speed varies with position •Wind speed distribution varies periodically (1 per revolution) •Gusts & Turbulences •Local changes of angle of attack