Environmental Engineering Reference
In-Depth Information
Chapter 5
Design of Robust Controllers for Load
Reduction in Wind Turbines
Asier Díaz de Corcuera, Aron Pujana-Arrese, Jose M. Ezquerra,
Aitor Milo and Joseba Landaluze
Abstract This chapter proposes a methodology to design robust control strategies
for wind turbines. The designed controllers are robust, multivariable and multi-
objective to guarantee the required levels of stability and performance considering
the coupling of the wind turbine. The proposed robust controllers generate col-
lective pitch angle, individual pitch angle and generator torque control signals to
regulate the electrical power production in the above rated power production zone
and to mitigate the loads in the components of the wind turbines, like the drive
train, tower, hub or blades, to increase their lifetime. The synthesis of these
controllers is based on the H
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norm reduction and gain scheduling control tech-
niques via Linear Matrix Inequalities. A wind turbine non-linear model has been
developed in the GH Bladed software package and it is based on a 5 MW wind
turbine defined in the Upwind European project. The family of linear models
extracted from the linearization process of the non-linear model is used to design
the proposed robust controllers. The designed controllers have been validated in
GH Bladed and an exhaustive analysis has been carried out to calculate fatigue
load reduction on wind turbine components, as well as to analyze load mitigation
in some extreme cases.
