@MASTERSTHESIS\{IMM2006-04813,
    author       = "S. C. Thomsen",
    title        = "Nonlinear Control of a Wind Turbine",
    year         = "2006",
    school       = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    type         = "",
    note         = "Supervised by Niels K. Poulsen, {IMM}.",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/4813-full.html",
    abstract     = "This thesis describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind conditions are considered, in which the rotational speed of the rotor and the generated power need to be stabilized at nominal values.

The methods investigated include gain scheduling, feedback linearization, sliding mode control and nonlinear inverse control. The gain scheduled controller has served as a basis of performance for the pure nonlinear methods.

Incomplete state knowledge and noisy measurements have been introduced in the simulation model. To provide state estimates, an extended Kalman filter has therefore been designed. The feedback linearization controller and the sliding mode controller, both proved advantageous compared to the gain scheduled controller. The sliding mode control law, however, resulted in the actuator limits being exceeded. Therefore, only feedback linearization, resulted in a control law, which could surpass the performance achieved with the gain scheduled controller."
}