Abstract: A wind turbine nacelle configured for mounting on a wind turbine tower and for supporting a rotor-supporting assembly, the nacelle comprising a main unit, and at least one auxiliary unit. The auxiliary unit accommodates a at least one component, e.g. a converter or transformer. To provide efficient transportation, lower costs and easier assembly, the operative component is suspended directly on the main unit.

Abstract: A method of handling a wind turbine component (54) for assembly or maintenance, comprises coupling one or more unmanned air vehicles (20) with the wind turbine component (54) so that at least a portion of the weight of the wind turbine component (54) can be supported and lifted by the one or more unmanned air vehicles (20). The method further comprises coupling one or more cranes (50) with the wind turbine component (54) so that at least a portion of the weight of the wind turbine component (54) can be supported and lifted by the one or more cranes (50). The method further comprises controlling the one or more unmanned air vehicle (20) and crane (50) in coordination to lift the wind turbine component (54) and manoeuvre said component (54) with respect to a wind turbine (52).

Abstract: There is presented a method for damping an edgewise vibration of a rotor blade of a wind turbine, wherein the method comprises measuring at the rotor blade a motion parameter of the edgewise rotor blade vibration, generating based on said motion parameter a blade pitch angle control signal, and damping the edgewise vibration of the rotor blade by pitching the rotor blade according to the blade pitch angle control signal, wherein the blade pitch angle control signal is arranged so that a resulting force on a rotor blade pitched according to the blade pitch angle control signal, in a direction of the edgewise vibration of the rotor blade in a coordinate system, which rotates with a rotor of the wind turbine, is opposite and proportional to the edgewise rotor blade vibration velocity.

Abstract: A method of determining an orientation of a nacelle of a wind turbine, wherein the nacelle carries a Global Navigation Satellite System (GNSS) sensor, the method comprising: yawing the nacelle between a series of orientations; obtaining locus data based on a series of calibration positions measured by the GNSS sensor, wherein each calibration position is measured by the GNSS sensor when the nacelle is in a respective orientation of the series of orientations; storing the locus data; after storing the locus data, measuring a new position with the GNSS sensor; and determining the orientation of the nacelle on the basis of the stored locus data and the new position.

Abstract: The present invention relates to an Electro-Thermal Heating element for a wind turbine blade comprising an electrically conductive resistive material; two active busbars for supplying electrical power to the electrically conductive resistive material; and at least one dummy busbar at a predetermined spacing between the two active busbars on the electrically conductive resistive material. The present invention is also directed to a method of repair of the Electro-Thermal Heating Element.

Abstract: A wind park with wind turbines and airborne wind energy systems where a first zone and a second zone is defined for at least one of the airborne wind energy systems such that the risk of collision between apart of that airborne wind energy systems and a part of one of the wind turbines is higher when the airborne unit of that airborne wind energy system is in the second zone than when it is in the first zone, and different control parameters are applied to the control of at least one of the wind turbine and the airborne wind energy system depending on the position of the airborne unit relative to the defined zones.

Abstract: In a first aspect of the invention there is provided a method of making a wind turbine component, the method comprising supporting a layup (14) of fibrous reinforcing material in a mould (12); providing a supply of resin (16); providing a supply of hardener (20) comprising at least a first hardener (20a) and a second hardener (20b), the second hardener being faster than the first hardener; mixing resin with the first and/or second hardener to create a resin mixture (24); supplying the resin mixture (24) to the layup (14) during an infusion process; monitoring one or more process parameters of the infusion process; and controlling the speed of the hardener (20) by varying the relative proportions of the first and second hardeners (20a, 20b) in the resin mixture (24) during the course of the infusion process in dependence upon the one or more process parameters.

Abstract: A method for controlling wind turbines of a wind farm is disclosed. The wind farm is positioned at a site which includes one or more turbulence generating structures, such as hills, valleys, trees or buildings. A wind direction at the site of the wind farm is detected, and one or more upstream wind turbines and one or more downstream wind turbines are identified, based on the detected wind direction, where each of the upstream wind turbines is arranged in front of one or more of the downstream wind turbines, as seen in the wind direction. If it is detected that turbulent wind conditions are occurring, based on measurements performed by the wind turbines of the wind farm, then at least one of the upstream wind turbines is controlled based on measurements performed by at least one wind turbine which is a downstream wind turbine relative to the upstream wind turbine.

Abstract: The invention relates to a method for controlling a wind turbine as virtual synchronous machine by determining the synchronous machine rotational speed rotational speed and the synchronous machine angle. The virtual synchronous machine rotational speed is determined based on a combination of a feedback of a damping power, a power reference for a desired power output of the wind turbine, a grid power supplied by the wind turbine to a power grid and a chopper power dissipated by the chopper and an inertial integration model, the synchronous machine angle is determined based on an integration of the synchronous machine rotational speed, and the damping power is determined based on the virtual synchronous machine rotational speed.

Abstract: Control of a wind turbine in a stop process where a stop controller is used to pitch the blades at a number of pre-set pitch rates including a first pitch rate and a second pitch rate. The stop controller is arranged to access desired pitch angles of the stopping process and add an envelope band to the desired pitch angles. In the stop process, pitching at a selected pitch rate among the number of pre-set pitch rates is performed, and the pitch rate is changed according to criteria to keep the pitch value within the envelope band.

Abstract: A method of determining an orientation of a nacelle of a wind turbine, wherein the nacelle carries a Global Navigation Satellite System (GNSS) sensor, the method comprising: yawing the nacelle between a series of orientations; obtaining locus data based on a series of calibration positions measured by the GNSS sensor, wherein each calibration position is measured by the GNSS sensor when the nacelle is in a respective orientation of the series of orientations; storing the locus data; after storing the locus data, measuring a new position with the GNSS sensor; and determining the orientation of the nacelle on the basis of the stored locus data and the new position.

Abstract: Aspects of the present invention relate to a method of voltage control for at least one wind turbine generator configured to absorb and supply reactive power on demand, the method comprises: receiving a dispatch signal from a power plant controller indicating a reactive power set point; determining a terminal voltage level of the at least one wind turbine generator; generating a reactive power correction value based on a deviation of the terminal voltage level from a voltage set point; adjusting the reactive power set point by the reactive power correction value; and controlling the at least one wind turbine generator according to the adjusted reactive power set point.

Abstract: A method for operating a cluster of a plurality of wind turbines is disclosed. For each of the wind turbines, one or more parameter values of a parameter being indicative for a condition occurring at the wind turbine are derived, based the measurements obtained by the wind turbine. In the case that a derived parameter value for a specific wind turbine exceeds a trigger value, measures for mitigating an effect of the condition at the specific wind turbine are initiated. The derived parameter values for the wind turbines of the cluster of wind turbines are compared to an expected distribution of the parameter values. In the case that a distribution of the derived parameter values differs from the expected distribution of the parameter values, the trigger value is adjusted, and the adjusted trigger value is subsequently applied when comparing the derived parameter values to the trigger value.

Abstract: The invention provides a wind turbine blade body manufacturing method, the method comprising the steps of: providing a mould (40) having an elongated mould surface (43), placing a movable insert (50) on the mould surface, in a first position, forming, with the insert in the first position, a first blade body having a first length (L1), placing the insert (50) on the mould surface, in a second position, and forming, with the insert in the second position, a second blade body having a second length (L2) which is different from the first length.

Abstract: A power plant comprising: a plurality of photovoltaic (PV) modules arranged in a first and a second region of the power plant, wherein the PV modules in the same region are electrically connected with each other and wherein the PV modules of the first region are electrically connected to a local grid of the power plant via a first converter, and the PV modules of the second region are electrically connected to the local grid via a second converter; and a wind turbine generator (WTG) which is arranged such that the WTG is able to cast a shadow over at least one of the PV modules; wherein the first region and the second region extend in a substantially radial direction away from the WTG such that at most one of the two regions is at least partially covered by the shadow of the WTG at any time.

Abstract: A wind turbine nacelle configured for mounting on a wind turbine tower and for supporting a rotor-supporting assembly, the nacelle comprising a main unit, and at least one auxiliary unit. To increase flexibility and improve assembly and maintenance procedures of the wind turbine, the auxiliary unit comprises at least two sub units each accommodating at least one wind turbine component, e.g. a converter or a transformer. The sub units are attached individually to the main unit or they are joined and attached as one component to the main unit.

Abstract: The present invention relates to control of a wind turbine in a stop process in response to a rotor stop signal. The rotor stop process comprises the steps of prior to receipt of the rotor stop signal, generating a stored pitch angle signal by storing pitch angle signals for at least a fraction of a rotor revolution, and determining at least one periodic component of the stored signal. The rotor blades of the wind turbine are controlled towards a feathering position using a pitch control signal containing the at least one periodic component.

Abstract: A wind turbine blade comprising a blade shell that extends in a spanwise direction from a root end of the blade to a tip end of the blade, the blade shell defining an internal blade volume within which at least one blade feature is located, the blade being provided with an RF position-identification means configured for detection by an RF detection means external to the blade to enable determination of a reference position for the blade and/or the blade feature. Aspects of the invention also relate to a method of detecting a reference position for a wind turbine blade.

Abstract: A method of installing a wind turbine (10) at an offshore location. The wind turbine (10) includes a tower (18) and an energy generating unit (16). The tower (18) is configured to be secured to a transition piece (12, 42). Prior to shipping, the method includes electrically coupling electrical devices and/or systems (52) by cables (54) to energy generating unit (16) or wind turbine tower (18) or a test dummy therefor. The electrical devices and/or systems (52) are configured to be attached to transition piece (12, 42) once the tower (18) is installed. The method includes testing and commissioning the electrical devices and/or systems (52) while electrically coupled to the cables (54). Prior to shipping and after testing and commissioning, the method includes storing the electrical devices and/or systems (52) and attached cables (54) inside the tower (18).

Abstract: The present invention relates to a method for stabilizing a rotor of a wind turbine during a time period following an abnormal grid event, the method comprising the steps of detecting an occurrence of the abnormal grid event, reducing an allowable rotor thrust from a first thrust limit to a second thrust limit, detecting that the abnormal grid event has ended, and maintaining the second thrust limit a selected time period after the abnormal grid event has ended. The present invention further relates to a wind turbine controller and a computer program product for performing this method.