Abstract: The invention relates to a wind turbine (2) comprising: a nacelle (8) provided on the top of a tower (12), a rotor including a hub (6) and a number of blades (4), a main shaft (16) configured to be driven by the rotor about a main axis and supported on the nacelle (8), a generator (28) having a generator rotor and generator stator, and a gear system (25) arranged to increase the rotational speed between said rotor and said generator rotor.

Abstract: A method of yawing a nacelle in a wind turbine having a yawing assembly comprising a drive-ring and a plurality of drives configured to exert a torque during movement along the drive-ring and thereby move the nacelle relative to the tower. The drive-ring is made of drive-ring segments joined in intersections. The method comprises defining a location for each intersection, defining a reference torque exerted by the drives when moving along the drive-ring, defining a reduced torque being lower than the reference torque, determining when a crossing drive moves across the location of an intersection, and to increase the lifetime, exerting the reduced torque by the crossing drive.

Abstract: Techniques for controlling the yaw of a wind turbine system by controlling a plurality of yaw drive actuators. When the yaw drive actuators are applying the same torque to all the motors, this can lead to some motors overspeeding, if the motor is not engaged when the yaw system is activated. Therefore, if the actual motor speed reference of a yaw drive actuator is higher than a specific motor speed reference, then an output signal to reduce the actual motor speed reference is applied to the yaw drive actuators with an actual motor speed reference higher than the specific motor speed reference.

Abstract: The present invention relates to a partly assembled structure in the form of a structure comprising a wind turbine tower, a nacelle arranged thereon and a vibration damper attached to the nacelle for damping vibrations of the combined wind turbine tower and nacelle within a selected frequency range, wherein the vibration damper is operatively connected to a main shaft of the nacelle, or wherein the vibration damper is attached to the nacelle via a nacelle transportation interface. The present invention further relates to a method of constructing a wind turbine and a method for damping Vortex induced vibrations of the combined wind turbine tower and nacelle within the selected frequency range.

Abstract: An electrical power generating assembly for a wind turbine. The electrical power generating assembly comprises a gearbox comprising a gearbox output shaft, a generator comprising a rotor that is coupled to the gearbox output shaft; and a current measuring module located between the gearbox and the generator. The current measuring module comprises: an electrical pickup mounted to the electrical power generating assembly, wherein the electrical pickup includes an electrical contact that engages with a slip ring associated with the rotor. The current measuring module further comprises: a first current measuring device mounted with respect to the electrical pickup to detect current flowing at least through the electrical pickup; and a second current measuring device mounted with respect to the electrical pickup to detect current flowing through at least a component associated with the gearbox output shaft.

Abstract: The invention relates to a spreader bar (1) for distributing a lifting force from a crane (2) onto a two lifting regions (3,4) f a load (5) to be lifted. The spreader bar comprises a frame (6) and first and second systems (7,8). Each system comprises a lifting pulley (9), a connector (10) for connecting the spreader bar to the respective lifting region via a main wire (11) guided by the lifting pulley, an actuator (15) for vertically moving the connector via an actuator wire (16), and a movably arranged suspension element (19) connecting the actuator wire and the main wire. A compensator (20) compensates for possible fluctuations in the vertical distance between the respective lifting region of the load and the spreader bar. Such fluctuations can be due to the crane or the load being located on a floating vessel. When the suspension element is engaged with a blocking element (23), the lifting force from the crane can be transferred to the main wire in order to lift the load.

Abstract: A jacking tool (70, 162, 174) for a wind turbine component (60) having an outer housing (62) and an internal rotatable member (64) disposed in the outer housing (62) and rotatable about a rotational axis (66) is disclosed. The jacking tool (70, 162, 174) includes a support pin (74, 164, 176) having a proximal end and a distal end that includes a bearing (112). The support pin (74, 164, 176) is configured to be selectively movable relative to the outer housing (62). The bearing (112) is configured to contact the internal rotatable member (64) to support the internal rotatable member (64) relative to the outer housing (62), and to allow the internal rotatable member (64) to rotate within the outer housing (62) while being supported by the jacking tool (70, 162, 174).

Abstract: A wind turbine rotor blade spar cap, the spar cap having a length and comprising: a stack comprising a plurality of layers of conductive material and at least one intermediate layer, wherein the layers of conductive material each have a length along the length of the spar cap in a first direction, wherein the intermediate layer is arranged between adjacent layers of the conductive material, wherein the intermediate layer includes a fibre fabric material having: a first edge extending in the first direction, a conductive portion having conductive fibres oriented in the first direction, a first border portion between the first edge and the conductive portion, the first border portion having a plurality of non-conductive fibres oriented in the first direction and no conductive fibres oriented in the first direction, and cross fibres oriented to cross the conductive fibres and the non-conductive fibres, and wherein the intermediate layer is bonded with the adjacent layers of the conductive material and is electri

Abstract: Embodiments herein describe operating wind turbines in an offshore park to provide auxiliary power to a local AC grid or to an onshore grid during a grid malfunction. In one embodiment, the offshore park is coupled via a HVDC link to an onshore grid. When the HVDC link is down, a substation in the park includes a backup generator for creating a weak grid for powering auxiliary systems in a pilot turbine. The wind turbines in the park can switch to an auxiliary control system help power the auxiliary systems in the substation and in other turbines. In another embodiment, the offshore park is AC coupled to an onshore grid using a transformer in the substation. The wind turbines can participate in a brown or black start following a grid fault by switching to operating using the auxiliary control system.

Abstract: Wind Turbine Blade (12) Leading Edge (24, 30, 88) Protection Method In a first aspect of the invention there is provided a method of applying an erosion shield (22) to a leading edge region (30) of a wind turbine blade (12). The method comprises providing a wind turbine blade (12) comprising a blade shell (26) having an aerodynamic profile and defining a leading edge region (30); providing an erosion shield (22) made of a polymer material, the erosion shield (22) having an inner surface (36) to be bonded to the leading edge region (30) of the blade shell (26), and an outer surface (38, 84, 98) to be exposed in use; activating (44) the inner surface (36) of the erosion shield (22), and cleaning (42) the inner surface (36) of the erosion shield (22) using a solvent.

Abstract: A method of forming a foundation (26) of a wind turbine (10) including a tower (12) having a base tower section (24), comprising: mounting a levelling apparatus (56) to an anchor cage (30), the anchor cage (30) including a plurality of anchor bolts (36) extending between an upper flange (34) and a lower flange (38), the levelling apparatus (56) being arranged between the upper and the lower flanges (34, 38); arranging the anchor cage (30) in an excavation pit (94); directing a cementitious material into the excavation pit (94) so that the upper flange (34) becomes at least partially embedded within the first cementitious material; allowing the cementitious material to cure to form a rigid body (28, 90); actuating the levelling apparatus (56) to raise the upper flange (34) from the rigid body (28, 90) into a levelled position; directing a grout material (32) into a space beneath the raised upper flange (34); and allowing the grout material (32) to cure to form a support layer.

Abstract: Techniques for determining the presence of ice at a wind farm with a number of wind turbines. The controller receives a current ambient temperature of the wind farm. The controller also receives a measured current wind speed from wind speed sensors of the wind turbines. The controller also receives an estimated current wind speed of each of the wind turbines that is based on measured performance parameters of the associated wind turbine. The controller determines a current wind speed difference between the measured current wind speed and the estimated current wind speed for each of the wind turbines, and determines a current delta distribution based on the current wind speed differences. The controller also determines whether an ice event has occurred, the determination being in dependence on the current ambient temperature and in dependence on the current delta distribution, and then outputs an outcome of the ice event determination.

Abstract: Controlling a wind turbine including measuring a wind speed for a location upwind of a wind turbine. Using the measured wind speed, a changed steady-state deflection of a structure of the wind turbine is predicted. The predicted changed steady-state deflection corresponds to a time when wind from the location is incident on the wind turbine. Oscillations of the structure are damped relative to the changed steady-state deflection. By damping the oscillations relative to the changed steady-state deflection, movements of the structure may be minimized when there is no predicted change in steady-state deflection, while permitting more rapid movements during transitions from one steady-state deflection to the predicted steady-state deflection, allowing more of the available power to be captured by the wind turbine.

Abstract: The present invention provides a method and controller for controlling noise emissions from individual blades (18) of a wind turbine (10), the method (60) comprising defining (720) a wind turbine model (321) describing dynamics of the wind turbine (10), the wind turbine model (321) including a description of intensity and direction of noise emissions from each individual blade (18) as a function of azimuthal angle (312); and applying (730) a model-based control algorithm (32) using the wind turbine model (321) to determine at least one control output (331), and using (740) the at least one control output (331) to control noise emissions from each individual blade (18).

Abstract: Operating a renewable energy power plant connected to a power network at a point of interconnection. The plant includes: one or more renewable energy generators connected to a collection point of the renewable energy power plant, and a connecting network connecting the collection point to the point of interconnection. One method includes: receiving one or more measurement signals indicative of measured power characteristics of the renewable energy power plant at the point of interconnection; determining a dynamic short circuit ratio (DSCR) at the point of interconnection based on the one or more measurement signals; determining an equivalent dynamic short circuit ratio (EDSCR) at the collection point based on the determined DSCR at the point of interconnection and one or more components of an impedance of the connecting network; and controlling the one or more renewable energy generators by determining and dispatching active power set points based on the determined EDSCR.

Abstract: A wind turbine rotor blade spar cap includes a stack of layers of conductive material. An intermediate layer is bonded between adjacent layers of the conductive material. The intermediate layer includes a portion of conductive material which is electrically coupled to the adjacent layers of conductive material so as to equipotentially bond the adjacent layers of the conductive material via the intermediate layer.

Abstract: There is provided a method of avoiding edgewise vibrations during a non-operational period of a wind turbine. The method comprises defining a non-operational period for a wind turbine arranged at a specific site, determining expected wind conditions at the specific site during the non-operational period and defining a plurality of potential yaw orientations for the wind turbine. The method further comprises determining the relative probability of edgewise vibrations occurring during the non-operational period for each potential yaw orientation based upon the expected wind conditions during the non-operational period, determining one or more preferred yaw orientations, which are the yaw orientations in which the probability of edgewise vibrations occurring is lowest, and arranging the wind turbine in one of the preferred yaw orientations during the non-operational period.

Abstract: A method of retrofitting a wind turbine (10) having a wind turbine tower (12) and a first energy generating unit (14) includes rotating at least a portion of the wind turbine tower (12). The wind turbine tower (12) is secured to a foundation (16) and has a first position on the foundation (16). The method includes rotating at least a portion of the wind turbine tower (12) from the first position to a second position. In the second position, the portion experiences less stress when the wind turbine (10) is operated in the same prevailing wind. The wind turbine tower (12) may have at least two sections (12a, 12b, 12c) and wherein rotating includes rotating one section relative to another section. One section may be secured to a foundation (16). In that case, rotating may or may not include rotating the section secured to the foundation (16).

Abstract: This disclosure proposes procedures and systems for discharging system capacitors and de-energizing power transmission systems having Modular Multilevel Converter (MMC) topologies by intelligent control of MMC cell components including configuration of bypass and insert switches using integrated DC choppers to effectively de-energize MMC cell capacitors and/or DC-link capacitors under operating conditions such as after a normal stop, for protection against over-voltages, dumping turbine energy, and under certain hardware fault conditions.

Abstract: There is provided a method of controlling power output of a wind turbine at below-rated wind speed, the method comprising: determining an indication of blade torsion of one or more rotor blades of the wind turbine in dependence on wind speed and/or rotor speed; determining a torsion-corrected blade pitch based on the indication of blade torsion; and using the torsion-corrected blade pitch to control pitch the one or more rotor blades.