Investigation of the maximum load alleviation potential using trailing edge flaps controlled by inflow data

The maximum fatigue load reduction potential when using trailing edge flaps on mega-watt wind turbines was explored. For this purpose an ideal feed forward control algorithm using the relative velocity and angle of attack at the blade to control the loads was implemented. The algorithm was applied to time series from computations with the aeroelastic code HAWC2 and to measured time series. The fatigue loads could be reduced by 36% in the computations if the in flow sensor was at the same position as the blade load. The decrease of the load reduction potential when the sensor was at a distance from the blade load location was investigated. When the algorithm was applied to measured time series a load reduction of 23% was achieved which is still promissing, but significantly lower than the value achieved in computations.