Abstract: A rotor for a wind turbine, to a rotor blade for a wind turbine, to a blade-fastening element for the fastening of a rotor blade, to a wind turbine, and to a method for mounting a rotor. A rotor for a wind turbine, comprising at least one rotor blade which extends from a blade tip to a face side, a hub having a blade-fastening element which, at the rotor-blade side thereof, has a blind hole for receiving a longitudinal bolt for the fastening of a rotor blade to the blade-fastening element, wherein the rotor blade has a fastening region which is of tubular form and which is arranged adjoining the face side, wherein the fastening region has at its outer circumferential surface and/or at its inner circumferential surface at least one thickened portion.

Abstract: A method for, in particular completely or partially, disassembling a tower of a wind power plant, comprising the following steps: selecting suitable disassembly measures as a function of the tower location and the tower characteristics; preparing the disassembly, in particular of the tower and optionally the surroundings; carrying out the disassembly; and transporting the disassembled tower away.

Abstract: A flange connection for a wind turbine, in particular a blade flange connection, having—a first flange part, in particular a blade receptacle of a rotor blade hub, a second flange part, in particular a rotor blade flange, and multiple bolts which hold the second component against the first flange part in a connected state, wherein the bolts are each screwed to the first flange part. It is proposed that the at least two bolts are in each case connected to one another by a tension means, a sensor arrangement, which detects a change in a tensile force transmitted by the tension means, being actively connected to the tension means. A wind turbine and a method for monitoring the flange connection of the wind turbine are also proposed.

Abstract: An airflow guiding device for the sound- and pressure-optimized supply of an airflow to an inlet nozzle of a fan, in particular a radial fan, wherein the inlet nozzle has a nozzle input opening with an incident flow angle, the airflow guiding device having: a frame device which extends along a longitudinal axis in an axial direction with a height between an inlet opening, through which the airflow flows into the frame device in an operating state, and an outlet opening, through which the airflow flows out of the frame device in the operating state, wherein the inlet opening has an inlet cross section with a minimum inlet cross-sectional width, and the outlet opening has an outlet cross section with a minimum outlet cross-sectional width which corresponds to the minimum inlet cross-sectional width or which is smaller than the minimum inlet cross-sectional width, and the frame device comprises a flow duct which connects the inlet opening and the outlet opening in terms of flow, wherein the outlet opening is con

Abstract: A method for operating a wind farm having a first wind power installation and a second wind power installation, to an associated wind power installation and to an associated wind farm. The second wind power installation is located in the wake of the first wind power installation in at least one wake wind direction. A tip-speed coefficient is determined from the ratio of a second tip-speed ratio of the second wind power installation and a first tip-speed ratio of the first wind power installation and a pitch-angle coefficient is determined from the ratio of a second pitch angle of the second wind power installation and a first pitch angle of the first wind power installation.

Abstract: Provided is a method for controlling a wind power installation, the wind power installation having a generator for the generation of electric current, the generator having an air gap with a variable air gap thickness, the wind power installation being controlled in a part load range by means of a control regulation, the wind power installation being controlled in a manner which is dependent on the air gap thickness, the control regulation being selected or set in a manner which is dependent on the air gap width.

Abstract: A method for controlling a wind power installation having a rotor operated with variable speed and having rotor blades that are adjustable in their blade angle. The installation is controlled in a partial-load range by an open-loop operating-characteristic control, which uses an operating characteristic. The operating characteristic presets a relationship between the rotational speed and a generator state variable to be set that is a generator power or torque. A value of the generator state variable preset by the operating characteristic is set in dependence on a detected speed. The installation is controlled in a full-load range by a closed-loop pitch control, in which the rotational speed is controlled to a speed setpoint value by adjusting the blade angles. In a presettable range of the partial-load range and/or in a transitional range from the partial-load range to the full-load range, the installation is controlled by a speed-power control.

Abstract: A method for providing a requested real power including receiving the requested real power at a transmission feed-in point; using a real power band with an upper band limit and a lower band limit, each of which is disposed with an offset from the requested real power. The real power band furthermore comprises at least one control threshold value between the upper band limit and the lower band limit. The method includes controlling at least one regenerative energy generator depending on the at least one control threshold value, in particular in order to provide the requested real power as transmission power at the transmission feed-in point.

Abstract: Provided is a method for controlling at least two frequency-converter-based infeeders. The method includes specifying a first droop for a first frequency-converter-based infeeder and specifying a second droop for a second frequency-converter-based infeeder, where the second droop is different from the first droop. The method includes, controlling the first frequency-converter-based infeeder in dependence on the first droop, and controlling the second frequency-converter-based infeeder in dependence on the second droop.

Abstract: Provided is a method for controlling, by means of field-oriented closed-loop control, an active rectifier which is electrically connected to a stator of a generator of a wind turbine. The generator has a rotor which is mounted so as to be rotatable about the stator and comprises the steps of determining a mechanical position of the rotor with respect to the stator, predefining DC components of rotor-fixed d and q coordinates for at least one 3-phase stator current, determining an AC component for the q coordinate at least as a function of the mechanical position of the rotor, modulating the determined AC component of the q coordinate onto the predefined DC component of the q coordinate, so that a modulated q coordinate is produced which has a DC component and an AC component, and controlling the active rectifier at least as a function of the modulated q coordinate and preferably as a function of the d coordinate.

Abstract: A method for operating a wind power installation for the purpose of generating electrical power from wind, wherein the wind power installation has an aerodynamic rotor having rotor blades that can be adjusted in their blade angle, and the rotor is operated at a settable rated rotor speed, wherein a turbulence class at a site of the wind power installation is determined, and the rated rotor speed is defined in dependence on the determined turbulence class.

Abstract: Thus there is provided a method of installing rotor blades of a wind turbine to a rotor hub of the wind turbine. The wind turbine has a tower having a tower longitudinal axis. The rotor hub has a first, a second and a third rotor blade connection. The rotor hub is rotated until the first rotor blade connection is at an angle of 90° or 270° with respect to the tower longitudinal axis. The first rotor blade is lifted substantially horizontally and fixed to the rotor blade connection. The rotor hub is rotated so that the second rotor blade connection is at an angle of 90° or 270° with respect to the tower longitudinal axis. The second rotor blade is lifted substantially horizontally and fixed to the second rotor blade connection. The rotor hub is further rotated until the third rotor blade connection is at an angle of 60° or 300° with respect to the tower longitudinal axis. The third rotor blade is lifted at an angle of ?=30° with respect to a horizontal and fixed to the third rotor blade connection.

Abstract: A method for pretensioning a tower of a wind power installation, comprising the steps: providing a tensioning device having an adapter element and/or a foundation arrangement and a tensioning element, and/or an adapter element and/or a foundation arrangement, fastening a lower end of a tensioning element a fastening means of the adapter element, fastening an upper end of a tensioning element to an upper end of the tower, tensioning the tensioning element at the lower end of the tensioning element and/or at the upper end of the tensioning element, wherein the tensioning of the tensioning element is effected by reduction of a clearance between the foundation and the adapter element.

Abstract: A method of repairing a wind turbine rotor blade, in particular an existing wind turbine rotor blade, that has erosion damage or transport damage. A first region is ablated into a surface or a surface coating of the rotor blade. An adhesive is applied to the ablated region, an erosion protection film is placed on the adhesive and the adhesive is cured.

Abstract: Provided is a method for controlling a wind power installation and/or a wind farm having at least one wind power installation, particularly in the case of asymmetrical network voltages, comprising: measuring a first voltage of a first phase, a second voltage of a second phase and a third voltage of a third phase of a three-phase electrical system, calculating a symmetrical negative-sequence voltage system from the measured voltages including a first negative-sequence voltage, a second negative-sequence voltage and a third negative-sequence voltage, predefining setpoints for a negative-sequence current system depending on the calculated, symmetrical negative-sequence voltage system including a first negative-sequence current component, a second negative-sequence current component and a third negative-sequence current component, wherein the setpoints are defined such that a balancing of the measured voltages is achieved, feeding an asymmetrical three-phase AC current into a wind farm network or an electrical su

Abstract: Rotor blade for a wind power installation, rotor for a wind power installation, and wind power installation. The disclosure relates in particular to a rotor blade for a wind power installation, having a rotor blade length, having a profile depth established between a leading edge and a trailing edge, and having a profile thickness established between a suction side and a pressure side, wherein the rotor blade has a trailing edge region, which adjoins the trailing edge and extends with a region extent of less than 20%, in particular less than 10%, of the profile depth in the direction of the leading edge, wherein the trailing edge region has at least one acoustic opening.

Abstract: A wind-power-installation tower segment, a wind-power-installation tower, a wind power installation, a use of a holding arrangement, a use of a first transport device and of a second transport device, and to methods for assembling a wind-power-installation tower segment and for assembling a wind-power-installation tower section.

Abstract: Provided is a method for feeding electrical power into an electrical supply network using a converter-controlled infeed apparatus. The apparatus feeds into a local network section of the electrical supply network at a network connection point. The network has further infeed apparatuses and consumers for consuming electrical power. The local section has a ratio of power able to be fed in using converters to a total power able to be fed in by all infeed apparatuses of at least 50%. A controller controls the infeed of the electrical power depending on a network state of the network. The controller has control behavior that depends on a network characteristic of the local section. The network characteristic is dependent on at least one property of the local section and at least one property of a further network section of the network or a determination that no further network section is present.

Abstract: Provided is a method for controlling a wind power system, that is to say a wind power installation or a wind farm comprising a plurality of installations, for feeding electrical power from wind into an electrical supply grid, and for damping low-frequency oscillations, in particular subsynchronous resonances, in the grid, wherein the grid has a line voltage with a nominal line frequency, wherein a damping control with a closed control circuit is used for damping the low-frequency oscillations, and the damping control for damping the low-frequency oscillations controls a feed-in of electrical power into the grid using a wind system control, the damping control is designed for a controlled system comprising the grid, the wind power system, and the wind system control, or parts thereof, wherein the damping control is designed such that it prevents and/or damps weakly damped modes in the closed control circuit.

Abstract: A method for detecting low-frequency oscillations, in particular subsynchronous resonances, in a grid is provided. The method includes recording a series of measurements, having measurement points, of a grid variable over a measurement time period, for performing a frequency analysis and multiplying the series a time-dependent sinusoidal test function for the same measurement time period. The test function is characterized by a test frequency and a test angle as phase angle. The series for each measurement point is multiplied by the test function in order to obtain a test product for each measurement point. The method includes adding the test products taking into consideration the mathematical sign thereof to give a product sum, and evaluating, depending on the product sum, whether the series of measurements has a low-frequency oscillation having a frequency in the region of the test frequency and a phase angle in the region of the test angle.