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.

The present invention provides a method of erecting a wind turbine on a wind turbine site. The wind turbine comprises 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 two damper units configured to dampen oscillations of the turbine tower, attaching one of the at least two damper units to one of the plurality of the tower sections on an outside thereof, and subsequently arranging said tower section in the tower structure, attaching a subsequent one of the at least two damper units to another one of the plurality of the tower sections on an outside thereof, and subsequently arranging said tower section in the tower structure, while the previous one of the at least two damper units is still attached to the previous one of the plurality of tower sections.

The present invention provides a method of erecting a wind turbine on a wind turbine site. The wind turbine comprises 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 two damper units configured to dampen oscillations of the turbine tower, attaching one of the at least two damper units to one of the plurality of the tower sections on an outside thereof, and subsequently arranging said tower section in the tower structure, attaching a subsequent one of the at least two damper units to another one of the plurality of the tower sections on an outside thereof, and subsequently arranging said tower section in the tower structure, while the previous one of the at least two damper units is still attached to the previous one of the plurality of tower sections.

Provided is a weighing device for determining a property of a rotor blade of a wind turbine. The weighing device includes a first seat for receiving the rotor blade at a first radial position of the rotator blade, a second seat for receiving the rotor blade at a second radial position of the rotor blade, a first weight cell for quantifying a first weight which is acting on the first weight cell, a second weight cell for quantifying a second weight which is acting on the second weight cell, and a first counterweight which is configured to alleviate the first weight. Notably, the first counterweight is lifted up from the ground when the rotor blade is received by the first seat of the weighing device. Furthermore, a method of determining the weight, the mass or the torque of a rotor blade of a wind turbine is also provided.

Provided is a weighing device for determining a property of a rotor blade of a wind turbine. The weighing device includes a first seat for receiving the rotor blade at a first radial position of the rotator blade, a second seat for receiving the rotor blade at a second radial position of the rotor blade, a first weight cell for quantifying a first weight which is acting on the first weight cell, a second weight cell for quantifying a second weight which is acting on the second weight cell, and a first counterweight which is configured to alleviate the first weight. Notably, the first counterweight is lifted up from the ground when the rotor blade is received by the first seat of the weighing device. Furthermore, a method of determining the weight, the mass or the torque of a rotor blade of a wind turbine is also provided.

A rotor blade of a wind turbine with a particle damping device having at least one cavity (3) with inner walls (4) delimiting an interior and with a medium arranged in the interior so as to be movable with respect to the inner walls (4). Additionally, a rotor blade is provided with a vibration-damping mechanism, and a method for manufacture of such a rotor blade.

The present invention relates to control of a wind turbine where nacelle vibration is reduced by use of blade pitching or generator torque modulation. The nacelle vibrations are reduced based on a position signal of the nacelle. An actuator signal is determined based on the position signal and applied to the actuator capable of reducing nacelle vibration. The actuator signal is gain adjusted based on a separation between the rotor frequency and tower vibration frequency.

The present invention relates to control of a wind turbine where nacelle vibration is reduced by use of blade pitching or generator torque modulation. The nacelle vibrations are reduced based on a position signal of the nacelle. An actuator signal is determined based on the position signal and applied to the actuator capable of reducing nacelle vibration. The actuator signal is gain adjusted based on a separation between the rotor frequency and tower vibration frequency.

A wind turbine blade comprising a blade shell that extends in a spanwise direction from a root end of the blade to a tip end of the blade, the blade shell defining an internal blade volume within which at least one blade feature is located, the blade being provided with an RF position-identification means configured for detection by an RF detection means external to the blade to enable determination of a reference position for the blade and/or the blade feature. Aspects of the invention also relate to a method of detecting a reference position for a wind turbine blade.

A wind turbine blade comprising a blade shell that extends in a spanwise direction from a root end of the blade to a tip end of the blade, the blade shell defining an internal blade volume within which at least one blade feature is located, the blade being provided with an RF position-identification means configured for detection by an RF detection means external to the blade to enable determination of a reference position for the blade and/or the blade feature. Aspects of the invention also relate to a method of detecting a reference position for a wind turbine blade.