Environmental Engineering Reference
In-Depth Information
Fig. 6.4 Floating wind
turbine [
12
]
Table 6.1 Basic
facts
of
Rated power
5 MW
NREL's OC3 turbine
Rated wind speed
11.6 m/s
Rated rotor speed
12.1 RPM
Rotor radius
63 m
Hub hight
90 m
flexibility. Nine DOFs for the blades, that is; three for blade flapwise tip motion for
the first mode, three for tip displacement for each blade for the second flapwise
mode, and another three for the blade edgewise tip displacement for the first
edgewise mode. The last two DOFs are for rotor- and tail furl. In total, this adds up
to 24 DOFs.
In order to utilize linear control techniques, a linear model is needed. The linear
model is also obtained form FAST. A model with a low number of DOFs is
preferred for the controller design, otherwise the model is simply too complicated
in order to get a feasible solution. Three DOFs are selected for the linear model,
they are; platform pitch (1 DOF) and drive train (2 DOFs). The drive train includes
