  The extreme loads experienced by the wind turbine in the extreme wind events
are critical for the evaluation of structural reliability. Hence, the load
alleviation control methods need to be designed and deployed to reduce the
adverse effects of extreme wind events. This work demonstrates that the extreme
loads are highly correlated to wind conditions such as turbulence-induced wind
shears. Based on this insight, this work proposes a turbulence-based load
alleviation control strategy for adapting the controller to changes in wind
condition. The estimation of the rotor averaged wind shear based on the rotor
loads is illustrated, and is herein used to statistically characterize the
extreme wind events for control purpose. To demonstrates the benefits,
simulations are carried out using high-fidelity aero-elastic tool and the DTU
10 MW reference turbine in normal and extreme turbulence wind conditions. The
results indicate that the proposed method can effectively decrease the
exceedance probability of the extreme loads. Meanwhile, the method can minimize
the loss of annual energy production in normal operating condition.
