Techniques for controlling rotor speed of a wind turbine. One technique includes defining a system model describing resonance dynamics of a wind turbine component, such as a wind turbine tower, where the system model has a nonlinear input term, e.g. a periodic forcing term. A transform is applied to the system model to obtain a transformed model for response oscillation amplitude of the wind turbine component, where the transformed model has a linear input term. A wind turbine model describing dynamics of the wind turbine is then defined, and includes the transformed model. A model-based control algorithm, e.g. model predictive control, is applied using the wind turbine model to determine at least one control output, e.g. generator torque, and the control output is used to control rotor speed of the wind turbine.

The invention provides a method for monitoring health state of blade root fastener, comprising the following steps: obtaining a sequence of acceleration signals representing the lateral vibration of the nacelle and a sequence of rotational speed signals representing the rotational speed of the rotor; analyzing the sequence of acceleration signals and the sequence of rotational speed signals to determine the amplitude of the nacelle at 2-time-frequncy of the rotational speed of the rotor; and determining the health state of the blade root fastener based on the amplitude. The invention also provides a system for monitoring the health state of the blade root fastener. Through the present invention, the health state of the blade root fastener can be determined with low cost and high precision, thereby improving the operation efficiency and operation safety of the wind turbine.

The method according to the invention for operating a wind turbine, comprising a tower and a rotor arranged at the top of the tower and having at least one rotor blade, which can be adjusted about a blade setting axis, has a first operating mode in which the at least one rotor blade has an operating angular position about the blade setting axis and a wind-force-dependent rotation of the rotor is converted into electrical power using a generator unit, which power is delivered from the wind turbine into an electrical network and/or stored, and a second operating mode in which the at least one rotor blade is adjusted by at least 60° and/or max. 110° about the blade setting axis relative to the operating angular position into a damping angular position, and a counter torque braking the rotor is controlled based on a vibration of the tower.

The invention provides a method of controlling operation of a wind turbine having a tower. The method includes determining an overall control output including lateral oscillation control for dampening lateral oscillation of the tower, and using the overall control output to control wind turbine operation. The method further includes receiving lateral oscillation sensor data indicative of a level of lateral oscillation of the tower, determining a rated lateral oscillation control output in dependence on the received lateral oscillation data, and receiving an indication of yaw error of the wind turbine. A lateral oscillation control output included in the overall control output is determined to be de-rated from the rated lateral oscillation control output when the indicated yaw error is above a predetermined lower threshold level.

Embodiments according to the invention describe a method for monitoring the state of the powertrain or tower of a wind turbine (10), said method having the steps of: detecting data of a state monitoring system which is provided for a structure of the wind turbine (10), said structure being mechanically coupled to the powertrain or tower; processing the detected data of the state monitoring system which is provided for the structure of the wind turbine (10), said structure being mechanically coupled to the powertrain or tower; and determining the state of the powertrain or tower from the processed data of the state monitoring system which is provided for the structure of the wind turbine (10), said structure being mechanically coupled to the powertrain or tower.

Provided is a method for controlling a wind turbine, in particular an electric generator of said wind turbine. The method includes an optimization during which a suitable operating parameter for controlling said wind turbine or generator thereof is determined, in particular in an iterative manner. The optimization includes providing a multidimensional space comprising a plurality of parameters; providing an objective function for said multidimensional space, e.g., a simplex has a shape of a triangle or a tetrahedron; and determining one parameter of said multidimensional space as a suitable operating parameter by applying said objective function to said multidimensional space, in particular in an iterative manner. The method includes selecting a suitable operating parameter as an operating parameter for said wind turbine or generator thereof; and operating said wind turbine or generator based on said operating parameter, in particular by controlling a converter connected to said generator.

A method of controlling a wind turbine for the avoidance of edgewise vibrations. The method comprises the steps of determining a whirling mode frequency of a rotor blade of the wind turbine; determining a rotational frequency of the rotor blade corresponding to the speed of the rotor blade; determining a threshold value for the whirling mode frequency based on the rotational frequency; and, reducing the speed of the rotor blade if the whirling mode frequency substantially equals or is less than the threshold value.

A wind turbine generator fault detection method is described. The method includes obtaining a first signal from a generator of a wind turbine and a second signal from a vibration sensor coupled to the wind turbine, the first signal representing an output current of the generator, and the second signal being a time-sampled signal representing vibrations of a bearing in the wind turbine. Determining a shaft rotation frequency signal from the first signal, the shaft rotation frequency signal representing a time-varying rotational speed of a shaft of the wind turbine. Resampling an envelope of the second signal based on the shaft rotation frequency signal to provide a third signal, the third signal being an angular sampled signal. Detecting, by the at least one processor, a fault in the bearing of the wind turbine by identifying a characteristic signature of a bearing fault in the third signal.

A multisensory system provides both temporal and spatial coverage capacities for auto-detection of bird collision events. The system includes an apparatus having a first circuitry to capture and store a series of images or video of a blade of a wind turbine; and a memory to store the images from the first circuitry. The apparatus also has one or more sensors to continuously sense vibration of the blade or for acoustic recordings; and a second circuitry to analyze the sensor data stream and/or the series of images or video to identify a cause of the vibration and to trigger the camera(s). A communication interface transmits data from the second circuitry to another device, wherein the second circuitry applies artificial intelligence or machine learning to control sensitivity of the one or more sensors.

Provided is a method for controlling a wind power installation, an associated closed-loop controller, an associated installation and a wind farm. The installation has an aerodynamic rotor which is operated at a variable rotating speed and has rotor blades that have adjustable blade angles. The installation in at least one operating range is closed-loop controlled by a closed-loop rotating speed control in which the rotating speed by adjusting a rotor status variable of the rotor blades is closed-loop controlled to a rotating speed target value, referred to as the target rotating speed. The closed-loop rotating speed control for adjusting the rotor status variable includes the use of a reserve value. In the event that the installation is not yet operating at a target output or a target moment, the reserve is obtained from a comparison of the target output or target moment and a momentary output or a momentary moment.