A method of forming a balanced rotor blade assembly includes measuring a weight of a plurality of sub-components of the rotor blade assembly excluding a core. A configuration of a core of the rotor blade assembly is determined. In combination, the core and the plurality of sub-components achieve a target weight distribution and moment. The core is then fabricated and assembled with the plurality of sub-components to form a rotor blade sub-assembly.

A method of forming a balanced rotor blade assembly includes measuring a weight of a plurality of sub-components of the rotor blade assembly excluding a core. A configuration of a core of the rotor blade assembly is determined. In combination, the core and the plurality of sub-components achieve a target weight distribution and moment. The core is then fabricated and assembled with the plurality of sub-components to form a rotor blade sub-assembly.

A method of forming a balanced rotor blade assembly includes measuring a weight of a plurality of sub-components of the rotor blade assembly excluding a core. A configuration of a core of the rotor blade assembly is determined. In combination, the core and the plurality of sub-components achieve a target weight distribution and moment. The core is then fabricated and assembled with the plurality of sub-components to form a rotor blade sub-assembly.

A method of forming a balanced rotor blade assembly includes measuring a weight of a plurality of sub-components of the rotor blade assembly excluding a core. A configuration of a core of the rotor blade assembly is determined. In combination, the core and the plurality of sub-components achieve a target weight distribution and moment. The core is then fabricated and assembled with the plurality of sub-components to form a rotor blade sub-assembly.

There is disclosed a method of balancing a set of first and second modular blade sections for a set of blades of a rotor of a wind turbine. The method comprises determining a mass moment of the first and second blade sections, the mass moment being determined about an axis equivalent to an axis of rotation of a hub of the turbine when the blade section is assembled onto the hub. A plurality of blade section groups 10 are defined, each comprising a first blade section of the set and at least one second blade section of the set, each blade section group having a blade section group mass moment about the axis. The first blade section and the at least one second blade section in each group are selected so as to satisfy a minimised total ballast condition, to minimise balancing ballast to be added to the set as a whole, or a minimised 15 ballasting difference condition, to minimise the difference in balancing ballast added to different blades, or both.

There is disclosed a method of balancing a set of first and second modular blade sections for a set of blades of a rotor of a wind turbine. The method comprises determining a mass moment of the first and second blade sections, the mass moment being determined about an axis equivalent to an axis of rotation of a hub of the turbine when the blade section is assembled onto the hub. A plurality of blade section groups 10 are defined, each comprising a first blade section of the set and at least one second blade section of the set, each blade section group having a blade section group mass moment about the axis. The first blade section and the at least one second blade section in each group are selected so as to satisfy a minimised total ballast condition, to minimise balancing ballast to be added to the set as a whole, or a minimised 15 ballasting difference condition, to minimise the difference in balancing ballast added to different blades, or both.

A method of erecting a wind turbine on a wind turbine site, the wind turbine comprising a turbine tower and a nacelle. The method comprises the following steps: providing a plurality of tower sections being arrangeable upon each other in a vertical orientation in a tower structure to form the turbine tower; providing at least one damper unit configured to dampen oscillations of the turbine tower; attaching a damper unit to one of the plurality of the tower sections on an outside thereof, and subsequently arranging the tower section in the tower structure, and arranging the nacelle on top of the tower structure while the damper unit is attached to a tower section in the tower structure.

A method of erecting a wind turbine on a wind turbine site, the wind turbine comprising a turbine tower and a nacelle. The method comprises the following steps: providing a plurality of tower sections being arrangeable upon each other in a vertical orientation in a tower structure to form the turbine tower; providing at least one damper unit configured to dampen oscillations of the turbine tower; attaching a damper unit to one of the plurality of the tower sections on an outside thereof, and subsequently arranging the tower section in the tower structure, and arranging the nacelle on top of the tower structure while the damper unit is attached to a tower section in the tower structure.

There is provided a method (40) of correcting blade pitch in a wind turbine (10) having a tower (12) and a plurality of rotor blades (18). The method (40) comprises: receiving (410) sensor output data from one or more wind turbine sensors (141), the sensor output data including data indicative of excitation of the tower (12) for a plurality of different pitch angles of a particular one of the blades (18); determining (420) a corrected pitch reference of the particular blade (18), the corrected pitch reference corresponding to a minimum tower excitation based on the received sensor output data; and, sending (430) the corrected pitch reference to a pitch actuator system (24) of the particular blade (18).

The present invention relates to a wind turbine rotor balancing method which compensates imbalances between the centres of gravity of the wind turbine blades, in both magnitude and position along said blades, so that the amount of mass needed to carry out this balancing method is minimized, while reducing the loads and vibrations associated with a position of the centre of gravity of the rotor not aligned with the axis of rotation thereof, wherein the invention further relates to the wind turbine rotor balancing system and the wind turbine balanced with the above method.