Abstract: Control methods and systems of a wind turbine belonging to an off-shore wind park that use, in case of malfunction of the load measuring system, one of the following pitch vectors for the calculation of the individual pitch command of each blade: the pitch vector being applied at the same time in one wind turbine of the wind park where the load measuring system works properly a mean value of the pitch vectors being applied at the same time in a group of wind turbines of the wind park where the load measuring system works properly; the pitch vector resulting from a control law, obtained from historic records of the wind turbine when the load measuring system worked properly, defining the pitch vector as a function of at least the wind speed V, if the former pitch vectors are not available.

Abstract: The invention provides a wind turbine having a system for positioning the rotor in an azimuthal reference position Azref and for maintaining it therein for a predetermined period of time, the wind turbine being arranged in test mode. Said rotor positioning system comprises a first controller (31) configured to generate a generator speed reference ?ref from the difference between the rotor azimuthal reference position Azref and the rotor azimuthal measured position Azmeas and a second controller (35) configured to generate a generator torque reference Tref from the difference between said generator speed reference ?ref and the generator speed measured ?meas.

Abstract: The invention provides a wind turbine having a system for positioning the rotor in an azimuthal reference position Azref and for maintaining it therein for a predetermined period of time, the wind turbine being arranged in test mode. Said rotor positioning system comprises a first controller (31) configured to generate a generator speed reference ?ref from the difference between the rotor azimuthal reference position Azref and the rotor azimuthal measured position Azmeas and a second controller (35) configured to generate a generator torque reference Tref from the difference between said generator speed reference ?ref and the generator speed measured ?meas.