Environmental Engineering Reference
In-Depth Information
Fig. 13.18 EOG load case: SA control via the 2VAR controller and comparison of the response
with the FB case
chain, perfectly worked in ''pushing down'' the peak values of stress demand,
forcing it to stay within the fixed limits.
Table
13.3
, as for the CLES controller examined above, shows the peak values
of base stress and top displacement for the FB and the 2VAR controlled cases. It
allows to conclude that the 2VAR control logic, in respect to the FB case, reduced
the peak base stress of 29 %, even at the cost of a 15 % increase of the peak top
displacement.
13.6.2 SA Control for the Parking Load Case
When a pitch-controlled wind turbine shuts down due to the high-velocity wind,
the loss of power leads to a sudden pitch of the rotor blades, leading to a ''sling-
shot'' effect, followed by a free-decay response. When parked, the wind turbine
