Abstract: The present invention relates to a wind turbine and a method of operating a wind turbine for reducing edgewise vibrations, wherein the wind turbine comprises a wind turbine control system having at least one vibration sensor for measuring the edgewise vibrations and a controller for receiving the vibration signal from the vibration sensor. The sensor unit is preferably an accelerometer arranged in a stationary frame of reference. The controller determines at least one whirling mode frequency and the vibration level thereof. The controller initiates a corrective action if the measured vibration level exceeds a threshold value. The corrective action is preferably an adjustment of the pitch angle of the wind turbine blades which in turn dampens the edgewise vibrations.

Abstract: The invention relates to a wind turbine with a generator and a method of assembling a generator thereof, wherein the generator comprises a rotor rotatably arranged relative to a stator. The rotor comprises a plurality of superconducting pole units arranged on a back iron which is spaced apart from a rotor structure by a number of thermally insulating plates or beams. Said plates or beams are located between either ends of the rotor and orientated relative to the rotational direction of the rotor. Each plate has a first end firmly connected to another first beam extending in an axial direction and a second end firmly connected to another second beam also extending the axial direction. The first beams are further firmly connected to the back iron while the second beams are further firmly connected to the rotor structure. The thermally insulating plates or beams provide a flexible and cheap support interface that is able to adapt to the tolerances of the individual components.

Abstract: The present invention relates to a method of correcting rotor imbalance and a wind turbine thereof. The correction method comprises measuring the vibrations within at least one time window and determining an imbalance factor and an imbalance phase. The values of the parameters in the equation for calculating the correction action are then updated based on the imbalance factor and an imbalance phase. A correction angle for each of the wind turbine blades is calculated using these adjusted parameters. The correction angle is used to aerodynamically balance the rotor, and a model may be used to determine the initial values of the parameters. Another imbalance factor and imbalance phase is determined based on another set of measurements. This imbalance factor is then used to calculate a mass moment for correcting the mass imbalance in the wind turbine blades. The weight and location of a balancing mass is finally calculated based on this mass moment and installed in the respective wind turbine blades.

Abstract: The present invention relates to a control method and a wind turbine configured to determine a load signal of at least one component of the wind turbine, and to calculate a damage rate based on this load signal. The control method calculates and monitors the damage rate in real-time, wherein the damage rate is normalised by using a first function defining a first transition phase. A second function is afterwards applied to the normalised damage rate which defines a second transition phase. These transition phases allows for a smooth transition between different operating modes of the wind turbine. The control method may further change the power output of the wind turbine relative to the nominal power output when the output signal of the second function is determined to be stable over at least one time period.

Abstract: The invention relates to a wind turbine comprising a plurality of individual yaw bearing units and a method of replacing a pad of such a yaw bearing unit. The yaw bearing unit comprises a caliper structure divided into an upper portion and a lower portion, wherein the lower portion can be dismounted without also dismounting the upper portion. An upper pad is provided between a flange providing support for a nacelle and a mainframe of the nacelle. A radial pad is arranged on a radial surface of the upper portion and contacts a stop element located at either ends of the upper portion. An adjustable lower pad is arranged in a through hole in the lower portion and can be replaced via a lower opening in the lower portion. The radial pad can be replaced in a sideward direction by removing one of the stop elements or replacing it in an axial direction by removing the lower portion.

Abstract: The present invention relates to a synchronous superconductive rotary machine with a superconductive rotor, a wind turbine, an assembly method and a repair method thereof. The rotor comprises a back iron connected to a thermally insulating support structure which is further connected to a base element. A coupling element is arranged on a peripheral surface of the base element for coupling to a matching coupling element located on a peripheral surface of a pole unit. The pole unit comprises a core element on which the coupling element is located and superconductive coils are wound on the core element. The pole unit is slid into position in an axial direction and fixed relative to the back iron by using fastening means. The base element, support structure and pole unit are wrapped in a thermal insulating laminate. This provides a simple and easy assembly and repair process that does require the rotor to be separated from the stator in order to replace a pole unit.

Abstract: The invention relates to a wind turbine with a generator and a method of assembling a generator thereof, wherein the generator comprises a rotor rotatably arranged relative to a stator. The rotor comprises a plurality of superconducting pole units arranged on a back iron which is spaced apart from a rotor structure by a number of thermally insulating plates or beams. Said plates or beams are located between either ends of the rotor and orientated relative to the rotational direction of the rotor. Each plate has a first end firmly connected to another first beam extending in an axial direction and a second end firmly connected to another second beam also extending the axial direction. The first beams are further firmly connected to the back iron while the second beams are further firmly connected to the rotor structure. The thermally insulating plates or beams provide a flexible and cheap support interface that is able to adapt to the tolerances of the individual components.

Abstract: A lifting device and method is provided for lifting and turning a rotor during the erection process of wind turbine structure. The lifting device comprises a base unit with a mounting adapted to be mounted to an outer surface of the hub. The lifting device is able to turn the rotor using a pivotal lifting arm arranged between two end plates or a moveable trolley assembly arranged on a track of the base unit. A power pack unit or another power unit is used to power the turning unit which turns the rotor around a turning point into an installation position. The lifting point is preferably aligned with the center of gravity of the rotor for providing a balanced lift.

Abstract: Wind turbine having a wind turbine tower, a nacelle provided on the wind turbine tower, a rotor hub rotatably mounted to the nacelle, and one or more wind turbine blades having a root end to be mounted to the rotor hub, a tip end, and pressure and suction sides connected to each other via a leading edge and a trailing edge. The wind turbine blade has a plurality of cross-sectional profiles arranged according to the surface of the suction side so that the surface of the suction side forms a line having a predetermined curvature which curves towards the pressure side of the wind turbine blade and/or forms an approximately straight line along at least part of the relative length. The line crosses each cross-sectional profile in that point on the pressure side where the maximum relative thickness of that profile perpendicular relative to its chord line is measured.

Abstract: A wind turbine blade vortex generator unit and a method for installing it, where a wind turbine blade has at least one series of vortex generator units formed of fins extending substantially perpendicular to the surface of the airfoil and substantially in a direction from the leading edge towards the trailing edge of the wind turbine blade. The vortex generator units each comprises a fin connected to an outer side of the fin base, and where the fin is delta shaped tapering from a trailing edge towards a leading edge and where each of the vortex generator units has a layer of adhesive on an inner side of the base that extends to an outermost periphery of the base. The vortex generator unit has exactly one fin, and the base has an airfoil shaped periphery with a rounded leading edge and a trailing edge.

Abstract: A wind turbine with a wind turbine tower, a nacelle on the tower, a rotor hub rotatably mounted to the nacelle, and at least one wind turbine blade having a blade root mounted to the rotor hub, a tip end, a pressure side and a suction side connected to each other via a leading edge and a trailing edge, a first shell part having inner and outer surfaces and a second shell part having inner and outer surfaces, the shell parts having flanges that extend outwards from the trailing edge of the shell parts and away from the outer surface with gluing surfaces which are glued together when the two shell parts are placed on top of each other. This allows the glue line to be moved out of the inner area defined by the shell parts so that the glue process can be controlled more effectively.

Abstract: The present invention relates a wind turbine comprising a wind turbine tower with a nacelle provided on the top to which a rotor hub with one or more wind turbine blades is rotatably mounted so that they form a rotor plane. A floating foundation having a upper section is mounted to the bottom of the wind turbine tower, wherein the foundation has a buoyant body configured to be installed at an offshore position having a water depth of about 40 m or more. The wind turbine blade comprises an inner blade section coupled to an outer blade section by a pitch junction in which a pitch mechanism is coupled to a pitch control system configured to regulate the pitch of the outer blade section relative to the inner blade section at wind speeds above a first wind speed. This allows the pitching to be used to counteract the tilting of the wind turbine caused by the different thrusts acting on the structure.

Abstract: The present invention relates to an installation tool for assembling a main rotor shaft unit and an assembly method thereof. The installation tool comprises a first element for supporting the generator end of the rotor shaft and a rotatable support plate is coupled to a second element of the installation tool via engaging coupling elements. The rotor shaft is rotated by a single crane unit via lifting elements mounted to the generator end, and then lifted out of the installation tool and placed on a floor. The bearing units are then mounted to the outer surface of the rotor shaft. The rotor shaft is afterwards lifted onto the installation tool so that the coupling element is brought into engagement and the rotor shaft is rotated on to the first element. This provides an installation tool that eliminates the need for two crane units to rotate the rotor shaft and reduces the amount of man-hours needed to assemble the rotor shaft unit by up to six hours.

Abstract: An electrical machine has a stator-rotor configuration in which the rotor has at least two poles. The poles are configured to rotate in an angle and to electromagnetically interact with one or more teeth that is a part of a stator adjoined in a fixed position to the electrical machine. The configuration forms a gap in the lateral direction between the poles and the teeth. At least one of the poles is formed of a permanent magnet material and a magnetic flux intensifier is arranged relative to at least one of the poles and one of the teeth. The magnetic flux intensifier is configured to concentrate the magnetic field lines between a pole and the teeth.

Abstract: A method for installing an inner blade part or a wind turbine blade and to a lifting bracket for use in performing said method, e.g., a inner blade part for a partial pitch wind turbine blade comprising an inner blade part and an outer blade part, said inner blade part comprising a first flange for connection to a hub flange at a wind turbine hub and a second flange for connection to an outer blade part, said flanges all comprising a number of bolts and/or bolt holes. The lifting bracket has a flange for connection to a suitable number of bolts and/or bolt holes at said second flange on the inner blade part, the flange having a first surface and an opposite second surface arranged for interfacing with the first flange, and further the lifting bracket also has at least one lifting lug and at least one counter weight.

Abstract: The present invention relates to a wind turbine having a wind turbine tower with a nacelle provided on the top to which a rotor hub with one or more wind turbine blades is rotatably mounted by a rotor shaft. A generator is arranged in the nacelle, wherein the superconducting rotor coils induce a current in the stator coils when the rotor is rotated, and wherein the stator coils are arranged in at least four phases. One or more converter modules convert the power output from the generator so that it matches the power of a power grid. The generator side of the converter modules comprises a number of rectifying circuits equal to the phases in the generator, while the power grid side comprises a number of inverting circuits equal to the phases of the power grid. This allows the transient of the electromagnetic brake torque relative to the nominal electromagnetic torque of the generator to be reduced.

Abstract: A wind turbine with two or more wind turbine blades having at least one continuous profile extending along the length of the blade. The continuous profile may be formed by a plurality of first and second projecting elements which extend in a chord-wise direction. The ratio between the height and length of the first and second element is at least 1:1. The height of the projecting elements may be tapered off from the trailing edge towards the leading edge and/or from the blade root towards the tip end. This allows the increase in strain forces generated in the wind turbine blade to be reduced by deforming the first and second elements in an edgewise direction. This also allows for a continuous reduction of the strain forces and a reduced thickness of the first and second elements which in turn saves material.

Abstract: A wind turbine and to a method for installing a generator for a wind turbine, in which a nacelle and a mainframe for installation of, e.g., a generator and a main shaft, is installed on top of a tower. The nacelle further has a nacelle cover extending over the main frame from the hub and to a rear end, covering components installed on the main frame. The nacelle cover has at least a first part and a second part, the first part having a interface for engagement with a corresponding interface on the second part, the second part of the nacelle cover housing a generator as one unit. By having the generator and the second part of the nacelle cover as a single unit, installation can be performed in one go and then only one hoist with a crane is needed.

Abstract: A method for assembly and installation of an offshore wind turbine, where components such as a nacelle, one or more tower sections and/or blades for at least one wind turbine is manufactured, assembled at or transported to a harbor area, where said components are loaded onto a transport and installation vessel and subsequently transported to an erection site. The method involves at least the steps of assembling at least one nacelle for a two-bladed wind turbine having hub with two sets of blade installation interfaces facing in a radial direction, the blade installation interfaces having a 180 degree angular distance therebetween, installing at least one, but preferably two inner blade parts to the hub, and arranging the at least one nacelle with the at least one inner blade part attached to the hub on the deck of a transport and installation vessel.

Abstract: The present invention relates to a method of controlling an idling wind turbine in which wind condition data and wind turbine position data are collected by a sensor system, a control system computes an optimal pitch angle for a rotor blade of the wind turbine, and a pitching system continuously turns the rotor blades in the same direction in multiples of 360 degrees. The present invention further relates to a wind turbine with a sensor system including a wind sensor that measures wind condition data in the vicinity of the wind turbine, and a control system including a computer that executes a control algorithm and processes sensor input from the sensor system to compute an optimal pitch angle value for a rotor blade on the hub. This allows pitching the rotor blade into angle in which the mechanical loads of that rotor blade are reduced to a minimum when idling.