Provided is a method for operating a wind turbine, an associated wind turbine and a wind park. The method comprises a) providing an indicator for the occurrence of a flow separation on a pressure side of a rotor blade of a rotor of the wind turbine, and b) changing an operational management of the wind turbine using the indicator, wherein the indicator comprises a pitch angle of the rotor blade. By using the pitch angle as an indicator, a flow separation on the pressure side of the rotor blade can be effectively prevented.

A method for protecting a wind turbine from an extreme change in wind direction includes receiving a wind direction and/or a wind speed at the wind turbine. When a change in the wind direction or the wind speed exceeds a predetermined threshold, the method includes determining a margin to stall and/or zero lift of the at least one rotor blade of the wind turbine as a function of an angle of attack or change in the angle of attack at a blade span location of at least one rotor blade of the wind turbine. The method also includes implementing a corrective action for the wind turbine (without shutting down the wind turbine) when the margin to stall and/or zero lift exceeds a predetermined value so as to avoid stall and/or negative lift on the at least one rotor blade during operation of the wind turbine.

A method for operating a wind turbine includes determining at least one wind condition of the wind turbine for a plurality of time intervals. The method also includes determining a status of the wind turbine at the beginning of each of the plurality of time intervals. Further, the method includes determining at least one vibration parameter of the wind turbine for one or more preceding time intervals of the plurality of time intervals. Moreover, the method includes predicting whether a trip event is imminent based on the at least one wind condition, the status of the wind turbine at the beginning of each of the plurality of time intervals, and the vibration parameter. Thus, the method further includes implementing a control action for the wind turbine so as to prevent the trip event.

A method of retrofitting vortex generators on a wind turbine blade is disclosed, the wind turbine blade being mounted on a wind turbine hub and extending in a longitudinal direction and having a tip end and a root end, the wind turbine blade further comprising a profiled contour including a pressure side and a suction side, as well as a leading edge and a trailing edge with a chord having a chord length extending there between, the profiled contour, when being impacted by an incident airflow, generating a lift. The method comprises identifying a separation line on the suction side of the wind turbine blade, and mounting one or more vortex panels including a first vortex panel comprising at least one vortex generator on the suction side of the wind turbine blade between the separation line and the leading edge of the wind turbine blade.

A rotor for a wind turbine, in particular a wind turbine, having a power of more than 1 MW, to a hub for a rotor of a wind turbine and to a wind turbine. A rotor for a wind turbine, in particular a wind turbine having a power of more than 1 MW, comprising a primary rotor blade, wherein the primary rotor blade extends from a first root region to a first blade tip having a first longitudinal extension, a secondary rotor blade, wherein the secondary rotor blade extends from a second root region to a second blade tip having a second longitudinal extension, the first longitudinal extension being larger than the second longitudinal extension.

This application provides a control method and device for avoiding run-away, and a wind turbine. The method may include: determining whether a brake system of the wind turbine has failed; if the brake system has failed, calculating an initial crosswind position based on a current wind direction angle, and enabling a yaw system of the wind turbine to perform a crosswind operation based on the initial crosswind position; performing a long-period and short-period filter processing on wind direction data acquired during a crosswind process to obtain an average and instantaneous wind direction angle respectively; determining whether a wind direction has a sudden change based on the average and instantaneous wind direction angle; and if the wind direction has a sudden change, calculating a new crosswind position based on the average wind direction angle, and enabling the yaw system to perform a crosswind operation based on the new crosswind position.

A method for controlling a wind power plant is described. The method comprises measuring a sound emission by means of at least one pressure sensor secured to the rotor blade; detecting a characteristic aeroacoustic sound for at least one stall based on the sound emission; and controlling or regulating one or several components of the wind power plant based on the detection of the characteristic aeroacoustic sound of the stall.

Methods of measuring a stall condition of a rotor of a wind turbine are disclosed. In one aspect a stall parameter is obtained on the basis of the power parameter and a thrust parameter; and the stall parameter compared with a threshold to determine a stall condition of the rotor.

Provided is a blade for a wind turbine, the blade including a joint section configured to connect the blade to a hub of the wind turbine; an active add-on member which is actuated by a corresponding trim actuator to alter aerodynamic properties of the blade; and a channel configured to supply a medium from the joint section to the active add-on member. A wind turbine and a method of preventing icing of the blade is also provided.

A sensor device for measuring flow-separation on an aerodynamic element, including a number of compliant elements with aerodynamic and/or structural properties designed to allow flow-induced vibrational motion in an air current and a sensor-element designed to measure vibrations of the number of compliant elements is provided. Further provided is an aerodynamic element, e.g. a wind turbine blade or an airfoil, with such sensor device, a method for controlling the angle of attack of an aerodynamic element, a controlling device and a wind turbine.