Patent ID: 8174137

Claim:
A method of controlling a buoyant wind turbine installation, comprising: providing the wind turbine installation; wherein the wind turbine installation comprises a buoyant body, a tower arranged over the buoyant body, a generator mounted on the tower that is rotatable in relation to the wind direction and fitted with a wind turbine, and an anchor line arrangement connected to anchors or foundations on a sea bed, wherein the generator is controlled in the constant power or RPM range by controlling the blade angle of the turbine blades by means of a blade angle controller; using a numerical model with the estimated incoming wind velocity as its input, to estimate the rotor velocity; and inputting the estimated rotor velocity into the blade angle controller, the blade angle controller controlling the blade angle based on the inputted estimated rotor velocity; whereby tower movements are not visible to the blade angle controller such that negative damping is not introduced into the installation.