A hub hydraulic assembly for a wind turbine rotor is provided that includes plural support structures distributed circumferentially about a rotation axis of the hub is provided. In a first angular section of the circumferential distribution, a first support structure is provided and in a second different angular section of the circumferential distribution, a second support structure is provided. The first support structure includes at least a first support cantilever having a mounting end configured to be mounted to the hub and a free end, wherein at least one hydraulic component of the hub hydraulic assembly is mounted to the first support cantilever. The second support structure includes at least a second support cantilever having a mounting end configured to be mounted to the hub and a free end, wherein at least one hydraulic component of the hub hydraulic assembly is mounted to the second support cantilever.

For installing a blade on a horizontal axis rotational hub of an offshore wind turbine, use is made of a blade installation device that is temporarily installed on the offshore wind turbine. A mounting part is mounted on the foundation of the offshore wind turbine and/or on a lower portion of the wind turbine mast. A crane mast is erected vertically and is supported by the mounting part. The crane mast has a track. A blade manipulator assembly includes a trolley moving over the track and one or more blade root engagement members that engage a root end of the blade. The blade installation device includes a hoist system with a crane boom that is mounted to a top end of the crane mast, a winch, and a winch driven cable. In the method, the trolley is brought in a lower position thereof and the blade root engagement members engage on the root end of the blade that is in the lower receiving position thereof. The cable of the hoist system is attached to the blade at a distance remote from the root end, preferably at a center of gravity of the blade. The method includes the lifting of the blade to the blade installation position by operating the winch of the hoist system and simultaneously moving the trolley along the track by the trolley drive.

A lifting yoke (30) supports and moves a wind turbine blade (20) during installation or service at a wind turbine (10). The lifting yoke (30) includes an elongate support beam (42) configured to be lifted and moved by a crane (32), a support element (96) connected to a first end (48) of the support beam (42), and a cradle support (58) connected to a second end (50) of the support beam (42). The support element (96) wraps around the blade (20) proximate a root end (22), while the cradle support (58) lifts and supports the blade (20) at a location between a center of gravity and a tip end (24) of the blade (20). The cradle support (58) includes a support bed (60) with an upper profiled surface (66) that contacts a downward-facing surface (44b) of the blade (20), and also includes a release device (72) and a brake device (76). The release device (72) disconnects one end (62) of the support bed (60) from the support beam (42) to allow the support bed (60) to pivot away from the blade (20), while the brake device (76) controls and slows the pivotal movement of the support bed (60) over a first portion of pivotal movement, thereby avoiding uncontrolled swinging that could impact the blade (20) again. The lifting yoke (30) is simplified in construction by having actively controlled elements only at the release device (72) and brake device (76), while providing improved lifting support for blades (20) that avoids localized points of high stress that can occur when lifting blades (20) with slings.

The present invention relates to a rotor blade (1) for a wind turbine (2), the rotor blade (1) comprising a first down conductor (6), extending from a tip section (3) to a root section (4), wherein the first down conductor (6) is electrically coupled with a root block (7) of the root section (4), wherein the root block (7) is electrically coupled with a second down conductor (8). The second down connector (8) is electrically coupled with a current distribution plate (9), wherein the current distribution plate (9) is attached to a fixation device (10) for fixing the rotor blade (1) to a first bearing ring (11a) of a bearing (11) of a hub (12). The invention also relates to a wind turbine (2) and to a method for assembling a rotor blade (1) to a hub (12) of a wind turbine (2) and establishing a conductive path between a first down connector (6) of the rotor blade (1) and the hub (12).

In a first aspect of the present invention there is provided a method of repowering a horizontal-axis wind turbine comprising a tower, a nacelle located rotatably at the apex of the tower, and a rotor having a hub and at least three used blades mounted pitchably to the hub and extending radially therefrom, the method comprising the steps of uninstall the at least three used blades from the hub, install at least three repower blades to the hub, each repower blade extending between a root and a tip, and each repower blade further comprising a connection point located between the root and the tip, install a plurality of blade connecting members, each blade connecting member being connected between corresponding connection points of a pair of repower blades; and install a tensioning system with the hub, the tensioning system being configured to adjust a tension in each blade connecting member.

According to a first aspect of the present invention there is provided a method of repowering a horizontal-axis wind turbine The wind turbine comprises a rotor rotatably mounted to a nacelle, the rotor comprising a plurality of used first wind turbine blades connected to a hub, and each blade comprising a blade shell. Each blade extends in a radial direction from a blade root to a blade tip and in a chordwise direction between a leading edge and a trailing edge. The rotor defines a rotor axis and a first rotor diameter. The method comprises increasing the rotor diameter such that the rotor defines a second rotor diameter that is greater than the first rotor diameter. The method further comprises attaching a connecting fixture to each blade, each connecting fixture defining a connection point for connecting a blade connecting member to the blade. The method further comprises connecting a blade connecting member between corresponding connection points of a pair of wind turbine blades such that each blade is connected to at least one other blade by a blade connecting member.

A wind turbine rotor blade is provided including an inboard region and an outboard region including a spanwise section associated with the development of an unstable aeroelastic mode. The disclosed rotor blade includes a leading-edge corrective mass arranged within the spanwise section, which leading-edge corrective mass is adapted to move the center of mass of the spanwise section towards the leading edge in order to suppress the development of an unstable aeroelastic mode. A method of manufacturing a wind turbine rotor blade is also provided.

A method of disengaging a rotor-lock of a wind turbine, the rotor comprising one or more blades, which due to the gravitational pull, generates a rotor torque which is opposed by a rotor-lock counter-torque from the rotor-lock, the method comprising: a) determining a direction of the rotor torque with a sensor system; b) applying a rotor-drive counter-torque to the rotor with a rotor-drive system, wherein the rotor-drive counter-torque acts to oppose the determined rotor torque and causes the rotor-lock counter-torque to reduce; c) during or after the application of the rotor-drive counter-torque, disengaging the rotor-lock mechanism; wherein the step of determining a direction of the rotor torque comprises applying a torque restriction to the rotor-drive based on the determined direction of the rotor torque, the torque restriction preventing the application of torque to the rotor by the rotor-drive system in the same direction as the rotor torque.

According to the present invention there is provided a method of assembling a modular wind turbine blade comprising first and second blade modules connectable together at an interface to form at least part of the modular wind turbine blade. The method comprises providing a first blade module and a second blade module. Each blade module comprises an outer shell defining an outer surface of the blade module, a connecting region of the outer shell defining an interface end of the blade module, and a longitudinally-extending spar cap embedded in the outer shell. The spar cap has a tapered end portion in the connecting region in which the thickness of the spar cap decreases towards the interface end of the blade module such that a tapered recess is defined in the outer surface of the blade module. The method further comprises arranging the first and second blade modules end-to-end with the tapered recesses aligned to define a bridge recess. The tapered recess of the first blade module defines a first end of the bridge recess, and the tapered recess of the second blade module defines a second end of the bridge recess. The method further comprises arranging a stack of layers in the bridge recess and spanning the interface between the first and second blade modules. The stack of layers comprises a plurality of pre-cured layers interleaved with pre-preg interlayers. The pre-preg interlayers comprise fibrous material that is pre-impregnated with uncured resin. The method further comprises applying heat to the stack of layers in the bridge recess such that the resin in the pre-preg interlayers mobilises in the bridge recess. The method further comprises curing the resin to integrate the pre-cured layers with each other to form a spar bridge spanning the interface, the spar bridge serving to connect the spar caps of the first and second blade modules.

The present invention relates to a rotor blade (1) for a wind turbine (2), the rotor blade (1) comprising a first down conductor (6), extending from a tip section (3) to a root section (4), wherein the first down conductor (6) is electrically coupled with a root block (7) of the root section (4), wherein the root block (7) is electrically coupled with a second down conductor (8). The second down connector (8) is electrically coupled with a current distribution plate (9), wherein the current distribution plate (9) is attached to a fixation device (10) for fixing the rotor blade (1) to a first bearing ring (11a) of a bearing (11) of a hub (12). The invention also relates to a wind turbine (2) and to a method for assembling a rotor blade (1) to a hub (12) of a wind turbine (2) and establishing a conductive path between a first down connector (6) of the rotor blade (1) and the hub (12).