Lifting device for wind turbine components

1. A lifting device for a wind turbine component comprising:

a yoke for connecting the wind turbine component to a crane, the yoke including at least one sensor for measuring at least one of the position, the speed, and the acceleration of the wind turbine component at least during a lifting operation of the component,

wherein the yoke further includes a pitching device for rotating the wind turbine component around a pitching axis when the wind turbine component is connected to the yoke,

wherein the lifting device further includes a controller for controlling the rotation of the pitching device around the pitching axis as a function of the measurement of the at least one sensor;

wherein the wind turbine component is a blade for a wind turbine, and

wherein the pitching device is configured for rotating the blade between a first position wherein the suction and pressure sides of the blade are vertically oriented and a second position wherein the suction and pressure sides of the blade are horizontally oriented as the blade is lifted.

2. The lifting device according to claim 1 , wherein the at least one sensor is positioned and oriented on the yoke, in order to measure the position and/or the speed and/or the acceleration of the yoke along a lifting direction and/or a plane orthogonal to the lifting direction.

3. The lifting device according to claim 1 , wherein the yoke is dimensioned and configured in such a way that the pitching axis is inclined of an angle comprised between 0 and 60 degrees with respect to a horizontal direction.

4. The lifting device according to claim 3 , wherein the yoke is dimensioned and configured in such a way that the pitching axis is horizontally oriented.

5. The lifting device according to claim 1 , wherein the yoke including a plurality of sensors for measuring at least one of a position, a speed and, the acceleration of at least two points of the wind turbine component.

6. A method for lifting a component, wherein the component is a blade for a wind turbine, the method comprising the steps of:

providing a lifting device for the component, the lifting device having a yoke for connecting the component to a crane, the yoke including at least one sensor for measuring at least one of the position, the speed, and the acceleration of the component at least during a lifting operation of the component, wherein the yoke further includes a pitching device for rotating the component around a pitching axis when the component is connected to the yoke, wherein the lifting device further includes a controller for controlling the rotation of the pitching device around the pitching axis as a function of the measurement of the at least one sensor, wherein the pitching device is configured for rotating the blade between a first position wherein the suction and pressure sides of the blade are vertically oriented and a second position wherein the suction and pressure sides of the blade are horizontally oriented as the blade is lifted;

lifting the component,

measuring the position and/or the speed and/or the acceleration of the component during the lifting step, and

rotating the component around the pitching axis depending on the position and/or the speed and/or the acceleration detected in the step of measuring.

7. The method according to claim 6 , wherein in the step of rotating the component a suction or a pressure side of the blade is exposed to the wind.

8. The method according to claim 6 , wherein in the step of rotating the component a leading or a trailing edge of the blade is exposed to the wind.

9. The method of claim 6 , wherein when the blade moves more than a predefined threshold in a horizontal plane, the component is rotated to pitch the component to generate more aerodynamic load.

10. The method of claim 6 , wherein wherein when the blade moves more than a predefined threshold in a vertical plane, the component is rotated to pitch the component to generate less aerodynamic load.