A method and system for improving the balance of a rotor in a wind turbine, including; determining blade load data associated with a selected rotor blade pair; determining, based on the blade load data, pitch imbalance data associated with the selected rotor blade pair, wherein the pitch imbalance data associated with a rotor blade pair is based on measurements of at least blade loading, rotor speed and wind speed; and, determining and applying pitch control inputs to one or both of the selected rotor blade pair in order to reduce the severity of the rotor imbalance.

Method of operating a wind turbine comprising a plurality of blades rotatable along their longitudinal axes using a pitch mechanism, and comprising one or more movable trailing edge surfaces. The method includes predicting, at a first moment in time, a high load for one or more of the blades at a second moment in time. The method further comprises actuating on one or more of the movable trailing edge surfaces of these blades such that the trailing edge surfaces have a wider range of control to counteract the predicted high loads before the second moment in time, and simultaneously pitching the blades such as not to negatively affect the operation of the wind turbine. The method furthermore comprises, at the second moment in time, actuating the one or more movable trailing edge surfaces of the at least one or more blades to counteract the high loads.

A method for stopping the operation of a wind turbine is disclosed. The method may generally include receiving signals associated with at least one operating condition of the wind turbine, analyzing the at least one operating condition with a controller of the wind turbine, implementing a first stopping procedure in order to stop operation of the wind turbine when analysis of the at least one operating condition indicates that a pitch system failure has occurred and implementing a second stopping procedure in order to stop operation of the wind turbine when analysis of the at least one operating condition indicates that a different wind turbine stop event has occurred.

A method for optimizing the operation of a wind turbine having a rotor with at least one rotor blade, a tower, and a wind turbine controller, comprises determining a first load status of the wind turbine based on metereological data acquired by sensors, including a turbulence intensity; determining a second load status of the wind turbine based on mechanical loads on at least one wind turbine component; and increasing a load of the wind turbine, if the determined first and second load status of the turbine are within selectable load limits. A wind turbine implementing the method is also disclosed.

A method of operating a wind turbine power generating apparatus including a wind turbine rotor having a wind turbine blade includes: a step of obtaining a load applied to the wind turbine blade; and a step of selecting an operation mode of the wind turbine power generating apparatus on the basis of the load, from among a plurality of operation modes including a normal operation mode and at least one load-suppressing operation mode in which the load applied to the wind turbine blade is smaller than in the normal operation mode.

A method of operating a wind turbine power generating apparatus includes a step of obtaining a wind direction of a wind; a step of obtaining at least one of a wind velocity of the wind or an index of turbulence degree of the wind velocity; and a step of selecting an operation mode of the wind turbine power generating apparatus from among a plurality of operation modes including a normal operation mode and at least one load-suppressing operation mode in which a load applied to a wind turbine blade is smaller than in the normal operation mode, on the basis of whether the at least one of the wind velocity or the index of turbulence degree is at least a threshold. The threshold of the at least one of the wind velocity or the index of turbulence degree is variable in accordance with the wind direction.

A bearing arrangement for a wind turbine includes a bed frame, a shaft configured for connecting a rotor with a generator of the wind turbine, a front bearing and a rear bearing both supporting the shaft rotatably around a shaft axis, a front bearing housing supporting the front bearing, the front bearing housing including one or more feet connected to the bed frame, a rear bearing housing supporting the rear bearing, the rear bearing housing including one or more feet connected to the bed frame, and a stiffening element connecting one of the feet of the front bearing housing and one of the feet of the rear bearing housing. Having the stiffening element allows a reinforcement of the connection between the front bearing housing, the rear bearing housing and the bed frame. The stiffening element reduces the deformation of the bearing housings and the bed frame.

The present invention relates to adjustment and/or drive units which can be used in wind power plants for adjusting the azimuth angle of the nacelle of the wind power plant or the pitch angle of the rotor blades, wherein such an adjustment and/or drive unit has at least two adjusting drives for rotating two assemblies which are mounted so as to be rotatable relative to each other, and has a control device for controlling the adjusting drives. The control device controls the adjusting drives in such a manner that the adjusting drives are braced relative to each other during the rotation of the two assemblies and/or when the assemblies are at standstill. The invention further relates to a wind power plant comprising such an adjustment and/or drive unit, and to a method for controlling such an adjustment and/or drive unit. According to the invention, the control device comprises a bracing-adjustment device for variably adjusting the intensity of the bracing of the adjusting drives as a function of a variable external load on the assemblies being adjusted, wherein the intensity can be determined by means of a load determining device. According to another aspect of the invention, an overload protection is included, wherein the individual loads of the individual adjusting drives are determined by load determining devices and, in the event that an adjusting drive reaches overload, the distribution of the drive torques is modified in such a manner that the adjusting drive reaching overload is relieved or at least not further loaded, and at least one further adjusting drive is more heavily loaded in a supporting manner or is less heavily loaded in a bracing manner.

A wind turbine system includes: a ring gear; a yaw drive unit including a pinion gear meshing with the ring gear, the yaw drive unit being configured to rotate the pinion gear; a yaw brake unit configured to generate a braking force for inhibiting rotation of the ring gear; a load information acquiring unit configured to acquire an external load applied to the ring gear; and a control unit configured to release the braking force of the yaw brake unit when a rotational torque generated on the ring gear by the yaw drive unit has been larger than the external load acquired by the load information acquiring unit, in switching the ring gear from a stationary state to a rotating state.

A wind turbine system comprising a nacelle mounted on a tower, a rotor having a plurality of blades and a boundary layer control system configured to control airflow through blade surface openings in each of the blades. The wind turbine system includes a control system configured to perform at least one of the following: to monitor an operational speed parameter of the wind turbine, and to activate the boundary layer control system if it is determined that the 1 operational speed parameter exceeds a predetermined speed parameter threshold; to monitor tower motion and to activate the boundary layer control system based on a determination of excessive tower motion; to monitor for a wind turbine shutdown condition, and to activate the boundary layer control system if it is determined that a wind turbine shutdown condition has been identified; and to monitor the aerodynamic loads on the blades, and to activate the boundary layer control system also based on a determination of excessive blade loads. The system thereby provides an approach to activating and deactivating the boundary layer control system to reduce operational risk to the wind turbine.