|Variable speed drives in modern wind turbines are used to maximize wind turbine efficiency when the turbine is running below rated power and to reduce loading on the drive-train.|
In addition, there is something called a pitch control of the blades which is usually used to limit the energy captured when the turbine is operation above rated wind speed.
The benefits of a more complex variable-speed drive, variable-pitch control of wind turbines is offset by control flexibility. That is, higher efficiency, better power quality, in addition to a longer useful life of the wind turbine.
Reliable high-performance controllers are essential in making wind turbine technology competitive. However, there is an immediate impact for pitch control on the overall cost of wind energy.
It is emphasized that the control of the wind energy conversion systems can be done through the application of linear parameter varying (LPV) gain scheduling techniques.
A straight forward design procedure and simple controller implementation can be used via the classical gain scheduling.
If the Advanced Control System of wind turbines is of interest, then it is recommended that you grab the Wind Turbine Control Systems: Principles, Modeling and Gain Scheduling Design by Fernando D. Bianchi, Ricardo J. Mantz, Hernan De Battista
Advanced Control System for Wind Turbines