A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a transient grid event and generates a torque command via a drive-train-damper control module. The torque command is configured to establish a default damping level of a torsional vibration resulting from the transient grid event. The controller also determines at least one oscillation parameter relating to the torsional vibration and determines a target generator torque level based thereon. The target generator torque level corresponds to an increased level of damping the torsional vibration relative to the default damping level.

The present invention relates to a method for operating a wind turbine (1). The wind turbine (1) comprises one or more wind turbine blades (5), each wind turbine blade (5) being connected to a blade carrying structure (4) mounted on a hub (3), via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The method comprises the steps of detecting an airborne object entering a predefined zone around the wind turbine (1), comparing a current tip height (H) of the wind turbine (1) to a maximum tip height value, the maximum tip height value representing a maximum allowable tip height under currently prevailing conditions. In the case that the current tip height (H) exceeds the maximum tip height value, a pivot angle (P) of wind turbine blades (5) is adjusted in order to decrease the tip height (H) of the wind turbine (1) to a value below the maximum tip height value.

The invention relates to a method for operating a wind power plant, a wind power plant designed to carry out the method, and a corresponding computer program product. In the method for operating a wind power plant comprising a rotor having angle-adjustable rotor blades and a generator rotationally connected thereto and having a controllable torque, the torque of the generator is limited to a maximum value which is linked to the blade pitch angle of the rotor blades such that the maximum value at the switch-on blade pitch angle value is less than or equal to the rated torque value (M.sub.Nenn) and the maximum value at a rated blade pitch angle which deviates from the switch-on blade pitch angle is equal to the rated torque value (M.sub.Nenn).

A system and method are provided for controlling a wind turbine to protect the wind turbine from anomalous operations. Accordingly, in response to receiving data indicative of an anomalous operational event of the wind turbine, the controller initiates an enhanced braking mode for the wind turbine. The enhanced braking mode is characterized by operating the generator at a torque setpoint that generates maximum available torque for a given set of operating conditions. Additionally, the torque setpoint is in excess of a nominal torque limit for the generator.

Provided is a method of controlling at least one wind turbine in case of a rotational overspeed situation, the method including: determining a current state related to the wind turbine; providing data related to the current state as input to a turbine model; predicting a load of at least one wind turbine component and power output of the wind turbine using the turbine model provided with the input for plural control strategies; comparing the predicted load and power output for the plural control strategies; and selecting that control strategy among the plural control strategies that satisfies a target criterion including the load and the power output.

A wind turbine plant and a power control method and device thereof are provided. The power control method comprises: controlling rotational speed and torque of a generator of the wind turbine plant based on an optimal rotational speed torque curve and a specific rotational speed torque curve, when receiving a power-limiting operation instruction or a power-releasing operation instruction; wherein, for each point on the optimal rotational speed torque curve, the specific rotational speed torque curve includes a point on an isopower curve starting from said point that satisfies a predetermined condition, and wherein the predetermined condition is that a corresponding power value of said point on the isopower curve is lower than a power value corresponding to a point on the optimal rotational speed torque curve at the same rotational speed value as said point on the isopower curve by a predetermined value.

A wind turbine is provided. The wind turbine includes a mechanical system, an electrical system and a controller. The controller is for determining an electrical capability limit of the electrical system according at least in part to one or more operating conditions of the wind turbine and one or more environment conditions of a site of the wind turbine, comparing the electrical capability limit of the electrical system and a mechanical capability limit of the mechanical system, and controlling the electrical system to operate at the smaller one of the electrical capability limit and the mechanical capability limit. A method for controlling a wind turbine comprising a mechanical system and an electrical system is also provided.

A method of treating a bearing system including in a wind turbine drive train during storage and/or transport, the drive train including a rotor coupled to a generator, the method includes: controlling the generator to deliver a driving torque causing the rotor to rotate about at least one revolution, in particular more than 100, or more than 1000 revolutions, is provided.

The present invention relates to a method for operating a wind turbine (1). The wind turbine (1) comprises one or more wind turbine blades (5), each wind turbine blade (5) being connected to a blade carrying structure (4) mounted on a hub (3), via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The method comprises the steps of detecting an airborne object entering a predefined zone around the wind turbine (1), comparing a current tip height (H) of the wind turbine (1) to a maximum tip height value, the maximum tip height value representing a maximum allowable tip height under currently prevailing conditions. In the case that the current tip height (H) exceeds the maximum tip height value, a pivot angle (P) of wind turbine blades (5) is adjusted in order to decrease the tip height (H) of the wind turbine (1) to a value below the maximum tip height value.

A wind turbine is provided. The wind turbine includes a mechanical system, an electrical system and a controller. The controller is for determining an electrical capability limit of the electrical system according at least in part to one or more operating conditions of the wind turbine and one or more environment conditions of a site of the wind turbine, comparing the electrical capability limit of the electrical system and a mechanical capability limit of the mechanical system, and controlling the electrical system to operate at the smaller one of the electrical capability limit and the mechanical capability limit. A method for controlling a wind turbine comprising a mechanical system and an electrical system is also provided.