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: A method for testing in field a wind turbine. The wind turbine being configured for providing power at a given rated voltage and at a rated frequency of 50 or 60 Hz; the method comprising connecting the wind turbine to an electric grid of a given rated voltage and of a rated frequency of 50 or 60 Hz through a conversion device that allows the adaptation of the features of the electric grid at the wind turbine side of said conversion device to the conditions requested by the tests to be performed to the wind turbine; that adaptation including the adaptation of the rated frequency of the electric grid to the rated frequency of the wind turbine, when they are different, so that identical tests to wind turbines configured for different rated frequencies can be performed in the same site.

Abstract: A planetary gear unit (21) of a gearbox of a wind turbine comprising a sun gear (27), planet gears (25, 25?), a ring gear (24), a planet carrier (29) and an outer casing (31); the ring gear (24) being mounted on the outer casing (31) ; the planet carrier (29) comprising a bogie plate (35) where planet gears (25, 25?) are rotatably mounted on planet shafts (41); the planet carrier (29) comprising a main body (51) and a backplate (53) which can be joined/disjoined to the main body (51) for facilitating the assembly/disassembly of the planetary gear unit (21); the planet carrier (29) being rotatably mounted on said outer casing (31) by means of a first bearing (72) in contact with said main body (51) at the rotor side and by means of a second bearing (73) in contact with said backplate (53) at the generator side.