The invention provides a method of shutting down a wind turbine, the wind turbine comprising a rotor with a plurality of blades; and a generator system coupled to the rotor. The method comprises: operating the generator system to generate electrical power and apply a load torque to the rotor; controlling the electrical power generated with a power reference signal; determining that a shutdown of the wind turbine is required; in response to the determination that a shutdown of the wind turbine is required, changing the power reference signal so as to increase the electrical power generated thereby slowing the rotor; determining that a speed of the rotor has reduced below a threshold; and in response to the determination that the speed of the rotor has decreased below the threshold, changing a pitch of the blades to further slow the rotor.

The invention relates to a method for controlling a wind turbine in partial and full load. In order to avoid disadvantages of switching between partial and full load controllers, the wind turbine control system is configured so that both the partial and full load controller provides control action during partial and full load. For that purpose, the partial and full load controllers are configured with variable gains, wherein gain scheduling is performed so that the gain of partial load controller is larger than the gain of the full load controller during partial load and vice verso so that the gain of the full load controller is larger than the gain of the partial load controller during full load.

A wind turbine drive system includes a plurality of drive devices, a state quantity detection unit, and a control unit. The plurality of drive devices are provided in a first structure (a nacelle), and a ring gear is provided in a second structure (a tower). Each of the drive devices includes a motor drive portion, a speed reducing portion, and a motor braking portion for braking the motor drive portion. The state quantity detection unit detects a load between a meshing portion of each of the drive devices and the ring gear. Based on the thus detected load for the each of the drive devices, the control unit controls at least one of the motor drive portion and the motor braking portion so as to reduce a degree of variation in the load among the drive devices.

A method for operating a wind turbine, includes: determining a value of a wind speed of an incident air mass at the wind turbine; if the determined value of the wind speed is greater than a first threshold value for the wind speed: reducing a rotational speed of a rotor of the wind turbine, and maintaining or increasing a generator torque acting upon the rotor; if the determined value of the wind speed is greater than a second threshold value for the wind speed, the second threshold value being greater than the first threshold value: reducing the rotational speed of the rotor, and reducing the generator torque acting upon the rotor.

A method for control of a wind power installation which is connected to an electrical supply network and which has a rotor with rotor blades which are adjustable in terms of their blade angle, is able to be operated at a variable speed and is prepared for generating an installation power from wind, wherein a blade angle control is provided for adjusting the blade angles, a closed-loop speed control is provided for closed-loop control of the speed, a closed-loop power control is provided for limiting the installation power, and the wind power installation is able to be operated at an operating point which can be specified, wherein the operating point is characterized at least by the speed and the installation power comprises operating the wind power installation at a first operating point with a first blade angle, checking for a curtailment request, where a reduction in the speed and/or installation power is requested, and if there is a curtailment request, determining a new operating point as the target operating point depending on the curtailment request, wherein the target operating point is characterized by a target speed and a target installation power, and determining a setpoint blade angle as the target blade angle for the target operating point, wherein in order to change the blade angle to the target blade angle, a feedforward control blade angle, or a feedforward adjustment rate describing an adjustment rate of the blade angle, is specified via a feedforward control blade angle control process, wherein the feedforward control blade angle control process gives the feedforward control blade angle or the feedforward control adjustment rate directly to the blade angle control for implementation.

The invention provides a wind turbine having a system for positioning the rotor in an azimuthal reference position Az.sub.ref and for maintaining it therein for a predetermined period of time, the wind turbine being arranged in test mode. Said rotor positioning system comprises a first controller (31) configured to generate a generator speed reference .sub.ref from the difference between the rotor azimuthal reference position Az.sub.ref and the rotor azimuthal measured position Az.sub.meas and a second controller (35) configured to generate a generator torque reference T.sub.ref from the difference between said generator speed reference .sub.ref and the generator speed measured .sub.meas.

The invention relates to control of a wind turbine comprising a plurality of multi-axial accelerometers mounted at different positions in the nacelle and/or in a top portion of the tower. The position and orientation of each accelerometer as mounted is obtained, accelerations in at least two different directions by each accelerometer are measured during operation of the wind turbine. From a number of predetermined mode shapes for the movement of the wind turbine is then determined an absolute position of at least one of the accelerometers during operation of the wind turbine based on the measured accelerations, the mount position and orientation of each accelerometer and the pre-determined mode shapes. Hereby a more precise absolute position during operation is obtained which can be used in the controlling of the turbine.

A system for controlling a wind turbine generator includes a rotor blade assembly having rotor blades and a pitch actuator to control a pitch of the rotor blades, a gear box coupled to the rotor blade assembly, a power generator coupled to the gear box, and a main controller. The main controller is configured to control the aerodynamic torque applied on the rotor blades based on pitch control commands, and separately configured to control a generator speed of the power generator based on torque control commands. The system further includes a pitch controller configured to receive pitch calculation information from the main controller, calculate the pitch control commands, and return the pitch control commands to the main controller. The system further includes a torque controller configured to receive torque calculation information from the main controller, calculate the torque control commands, and return torque control commands to the main controller.

A method for controlling a wind turbine comprising inputting an actual value of rotational speed and a rotational speed setpoint into a control and outputting a set point value for a generator torque from the control. Inputting the set point value for the generator torque into a limiter with a predefinable upper and lower limit and outputting a limited torque value that is fed into a converter control. Increasing the actual value of the fed-in electrical power by an additional amount of power in response to a boost signal, wherein the fed-in electrical power and the additional amount of power are combined into an aggregated power setpoint value. Determining the set point value for the generator torque from the aggregated power setpoint value and applying the set point value for the generator torque in the boost operation to the limiter both as the upper limit and as the lower limit.

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).