Abstract: A system for measuring displacements of a blade root of a rotor blade of a wind turbine includes a hub, and a rotor blade coupled to the hub by a pitch bearing. The system further comprises a reference plane and at least one displacement sensor. The reference plane is configured to move with the rotor blade as the rotor blade moves relative to the hub while the displacement sensor is fixed to the hub and the displacement sensor is configured to detect a displacement of the reference plane relative to the hub without physical contact. Alternatively, the reference plane has a fixed position with respect to the hub while the displacement sensor is fixed to the rotor blade and the displacement sensor is configured to detect a displacement of the reference plane relative to the rotor blade without physical contact.

Abstract: The present disclosure relates to wind turbine blades, devices and methods for reducing vibrations in wind turbines, particularly during installation. In an aspect, a device for mitigating vibrations of a blade of a wind turbine during standstill is provided. The device comprises a flexible base having a first connection area and a second connection area, the first connection area being configured to be attached to the second connection area to form a removable attachment. The device further comprises one or more airflow modifying elements attached to the flexible base. The flexible base is configured to fit around a portion of the rotor blade such that the removable attachment is positioned substantially at a leading edge of the blade. The present disclosure further relates to methods for mitigating vibrations in a parked wind turbine blade and to sleeves for wrapping around a portion of a wind turbine blade.

Abstract: A rotor blade for a wind turbine includes at least one blade segment with at least one shell member defining an airfoil surface. The shell member(s) includes a sandwich panel configuration having one or more inner skin layers, a core material, and one or more outer skin layers. The outer skin layer(s) includes one or more first fibers, whereas the inner skin layer(s) includes one or more different second fibers. Further, the first fiber(s) of the outer skin layer(s) have a higher elastic modulus than the second fiber(s) of the inner skin layer(s).

Abstract: A system for measuring displacements of a blade root of a rotor blade of a wind turbine is disclosed. The system comprises a hub, a rotor blade coupled to the hub by a pitch bearing. The system further comprises a reference plane and at least one displacement sensor. The reference plane is configured to move with the rotor blade as the rotor blade moves relative to the hub while the displacement sensor is fixed to the hub and the displacement sensor is configured to detect a displacement of the reference plane relative to the hub without physical contact. Alternatively, the reference plane has a fixed position with respect to the hub while the displacement sensor is fixed to the rotor blade and the displacement sensor is configured to detect a displacement of the reference plane relative to the rotor blade without physical contact.

Abstract: A method for retrofitting a wind turbine blade with a replacement blade tip segment includes producing a replacement blade tip segment with an internal beam receiver section, and producing a beam structure. The existing blade tip segment is cut away from the wind turbine blade, wherein the cut defines a chord-wise joint line at the remaining blade root segment of the wind turbine blade. The beam structure is fixed into spar structure of the blade root segment. The replacement blade tip segment is aligned and connected with the blade root segment in a span-wise direction so that the beam structure moves into the beam receiver section. A finish surface can be provided to the blade shell components of the blade root segment and the replacement tip segment at the joint line.

Abstract: The present disclosure is directed to a lift system for a rotor blade of a wind turbine. The lift system includes a lifting device having at least one cradle. The cradle has a profile that corresponds to at least one of the exterior surfaces of the rotor blade so as to support at least a portion of the rotor blade. Further, the lift system includes a positioning assembly having at least one distance sensor mounted to the hub and at least one visual sensor mounted to the lifting device. Thus, the distance sensor is configured to identify a distance from the hub to the lifting device and the visual sensor is configured to identify a position of the rotor blade in the cradle.

Abstract: A method for retrofitting a wind turbine blade with a replacement blade tip segment includes producing a replacement blade tip segment with an internal beam receiver section, and producing a beam structure. The existing blade tip segment is cut away from the wind turbine blade, wherein the cut defines a chord-wise joint line at the remaining blade root segment of the wind turbine blade. The beam structure is fixed into spar structure of the blade root segment. The replacement blade tip segment is aligned and connected with the blade root segment in a span-wise direction so that the beam structure moves into the beam receiver section. A finish surface can be provided to the blade shell components of the blade root segment and the replacement tip segment at the joint line.

Abstract: The present disclosure is directed to a lift system for a rotor blade of a wind turbine. The lift system includes a lifting device having at least one cradle. The cradle has a profile that corresponds to at least one of the exterior surfaces of the rotor blade so as to support at least a portion of the rotor blade. Further, the lift system includes a positioning assembly having at least one distance sensor mounted to the hub and at least one visual sensor mounted to the lifting device. Thus, the distance sensor is configured to identify a distance from the hub to the lifting device and the visual sensor is configured to identify a position of the rotor blade in the cradle.

Abstract: A system and method for mounting a component to an internal web of a wind turbine blade includes, at a first mounting location on the internal web, at least one through-hole defined through the internal web. A bushing is located within the through-hole and is encased within an adhesive applied between the bushing and a wall of the through-hole. A plate is attached to each of the opposite panels of the internal web at the mounting location against an end face of the bushing, with each plate having a hole therein that is aligned with the through-hole. For mounting the component at the mounting location, a bolt is passed completely through the plates and bushing for attachment of a frame of the component to one of the plates.

Abstract: A system and method for mounting a component to an internal web of a wind turbine blade includes, at a first mounting location on the internal web, at least one through-hole defined through the internal web. A bushing is located within the through-hole and is encased within an adhesive applied between the bushing and a wall of the through-hole. A plate is attached to each of the opposite panels of the internal web at the mounting location against an end face of the bushing, with each plate having a hole therein that is aligned with the through-hole. For mounting the component at the mounting location, a bolt is passed completely through the plates and bushing for attachment of a frame of the component to one of the plates.

Abstract: A root extender for coupling a rotor blade to a hub of a wind turbine is disclosed. The root extender may generally include a body defining a longitudinal axis between a first end and a second end. The first end may define a first planar surface configured to be positioned adjacent to the hub and the second end may define a second planar surface configured to be positioned adjacent to the rotor blade. The second planar surface may be oriented at a cone angle relative to the first planar surface. In addition, the longitudinal axis may be oriented at a non-perpendicular angle relative to the first planar surface.

Abstract: A wind turbine blade is presented. The blade includes an upper shell member having a spar cap disposed on an internal surface of the upper shell, and a lower shell member having a spar cap disposed on an internal surface of the lower shell. The spar cap of the upper shell member, the spar cap of the lower shell member or both the spar caps include at least one cavity structure along a longitudinal length of the blade. A shear web extends between the spar caps along the longitudinal length of the blade, with a transverse end of the shear web positioned in a cavity of the at least one cavity structure, wherein a ratio of a width of the shear web to a bond thickness of the shear web with a side wall of the cavity structure is between about 1:1 and about 15:1.

Abstract: A system and method for deicing a wind turbine rotor blade includes simultaneously directing heated air through an internal leading edge circulation loop and a separate internal trailing edge circulation loop within the rotor blade.

Abstract: A root extender for coupling a rotor blade to a hub of a wind turbine is disclosed. The root extender may generally include a body defining a longitudinal axis between a first end and a second end. The first end may define a first planar surface configured to be positioned adjacent to the hub and the second end may define a second planar surface configured to be positioned adjacent to the rotor blade. The second planar surface may be oriented at a cone angle relative to the first planar surface. In addition, the longitudinal axis may be oriented at a non-perpendicular angle relative to the first planar surface.