Abstract: A method for compensating an imbalance of a wind rotor of a wind turbine includes applying at least one test-offset to a parameter characterizing a state of the wind rotor, wherein the imbalance depends on the parameter; measuring for the at least one test-offset an acceleration of the wind turbine, wherein the acceleration depends on the imbalance; and determining a compensation-offset based on the measured acceleration, wherein the imbalance is at least partially compensated, when the compensation-offset is applied to the parameter. Furthermore, a corresponding wind turbine includes a control unit configured to carry out the above method.

Abstract: A method for compensating an imbalance of a wind rotor of a wind turbine includes applying at least one test-offset to a parameter characterizing a state of the wind rotor, wherein the imbalance depends on the parameter; measuring for the at least one test-offset an acceleration of the wind turbine, wherein the acceleration depends on the imbalance; and determining a compensation-offset based on the measured acceleration, wherein the imbalance is at least partially compensated, when the compensation-offset is applied to the parameter. Furthermore, a corresponding wind turbine includes a control unit configured to carry out the above method.

Abstract: A method of controlling a wind turbine by adjusting a blade pitch angle and at least one blade add-on of at least one wind turbine rotor blade has the blade add-on, the method including: adjusting a setting of the add-on to meet a control objective while temporarily maintaining a setting of the blade pitch angle.

Abstract: Provided is a method of estimation of rotor operational characteristics, in particular rotor speed, rotor azimuth and rotation direction, of a rotating rotor of a wind turbine, the method including: measuring pulse rising edge time and pulse falling edge time of pulses generated by each of multiple proximity sensors originating from multiple detection targets arranged on the rotor; estimating values of parameters associated with the sensors and/or targets, in particular parameters associated with the positioning and/or detection range of at least one sensor and/or the parameters associated with the positioning and/or size of at least one target, based on the measured pulse rising edge times and pulse falling edge times; estimating rotor operational characteristics, in particular a rotor speed and/or a rotor azimuth and/or a rotation direction, based on the measured pulse rising and/or falling edge times and/or the estimated values of parameters associated with the sensors and/or targets.

Abstract: Provided is a method of determining a wind parameter value for use in a wind turbine control system, the method including (a) receiving a plurality of wind measurement signals, wherein each wind measurement signal is provided by a respective wind sensor among a plurality of wind sensors, (b) determining a set of statistical values based on the wind measurement signals, (c) calculating a weighting factor for each wind measurement signal based on the set of statistical values, and (d) calculating the wind parameter value as a weighted sum by applying the calculated weighting factors to the corresponding wind measurement signals. Further, a corresponding system and a wind turbine with such a system are provided.

Abstract: Apparatus and methods are described herein for providing a cooling system for an electromagnetic machine. In some embodiments, an apparatus includes a structure for an electromagnetic machine including a first outer support member that is configured to support a conductive winding or a magnet and a second support member that is disposed at a non-zero distance from the first support member. An elongate structural member has a first end coupled to the first support member and a second end coupled to the second support member and extends between the first support member and the second support member. The elongate structural member defines an interior channel that extends between the first end and the second end of the elongate structural member. The channel is configured to convey a cooling medium therethrough to cool at least a portion of the electromagnetic machine.

Abstract: A method for balancing a rotor of a rotary machine, wherein the rotor includes at least two rotor blades and a rotor shaft, includes receiving at least one measurement of either a load, an acceleration, or a displacement that pertains to at least one bending moment acting on the rotor shaft, determining at least one value of the at least one bending moment acting on the rotor shaft based, at least in part, on the received at least one measurement, and determining a pitch offset angle value of at least one rotor blade that facilitates reducing the at least one bending moment acting on the rotor shaft.

Abstract: A method for controlling a rotational speed of a rotor having at least one rotor blade, a rotor shaft, and an electrical generator coupled thereto. The method includes controlling a torque of the rotor shaft by controlling a torque of the electrical generator, alternating between changing an angle of pitch of the at least one rotor blade and maintaining the angle of pitch of the at least one rotor blade substantially constant, and maintaining a substantially constant rotational speed of the rotor during variable wind speeds above a predetermined rated wind speed.

Abstract: A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

Abstract: A technique is provided for operating a wind farm at increased rated power output. The technique includes sensing a plurality of operating parameters of the wind turbine generator, assessing the plurality of operating parameters with respect to respective design ratings for the operating parameters, and intermittently increasing a rated power output of the wind turbine generator based upon the assessment.

Abstract: A wind turbine includes a tower, a nacelle supported at an upper end of a tower, a rotor having at least one blade and being arranged at the nacelle, and a vibration load reduction system disposed at either the tower or the nacelle. The vibration load reduction system includes a base, at least two columns extending from the base, and a flowable mass located within the base and the at least two columns.

Abstract: A system and method of operating a wind farm, having multiple wind turbine generators, at high wind speeds is provided. Wind speeds at individual wind turbine generators are monitored and a signal is transmitted from the wind turbine generators to a wind farm control system based on the monitored wind speeds. Rate of change of collective power output of the wind farm is temporally monitored and is controlled by coordinating of operational states of the wind turbine generators based upon the signals transmitted by the one or more wind turbine generators, operating conditions of the wind turbine generators and the monitored rate of change of power output of the wind farm.

Abstract: A system and method for controlling power ramp rate of a wind farm is provided. The wind farm includes a plurality of wind turbine generators and a wind farm control system. The wind farm control system is operable to monitor rate of change of collective power output of the wind turbine generators, and to limit the rate of change of collective power output by generating a power output rate limiting signal based on the monitored rate of change of collective power output of the wind turbine generators and a desired collective power ramp of the wind turbine generators and applying the power output rate limiting signal to the plurality of wind turbine generators.

Abstract: A method for reducing at least one of loads, deflections of rotor blades, or peak rotational speed of a wind turbine includes storing recent historical pitch related data, wind related data, or both. The stored recent historical data is analyzed to determine at least one of whether rapid pitching is occurring or whether wind speed decreases are occurring. A minimum pitch, a pitch rate limit, or both are imposed on pitch angle controls of the rotor blades conditioned upon results of the analysis.

Abstract: A method for reducing load and providing yaw alignment in a wind turbine includes measuring displacements or moments resulting from asymmetric loads on the wind turbine. These measured displacements or moments are used to determine a pitch for each rotor blade to reduce or counter asymmetric rotor loading and a favorable yaw orientation to reduce pitch activity. Yaw alignment of the wind turbine is adjusted in accordance with the favorable yaw orientation and the pitch of each rotor blade is adjusted in accordance with the determined pitch to reduce or counter asymmetric rotor loading.

Abstract: A method for controlling a wind turbine having twist bend coupled rotor blades on a rotor mechanically coupled to a generator includes determining a speed of a rotor blade tip of the wind turbine, measuring a current twist distribution and current blade loading, and adjusting a torque of a generator to change the speed of the rotor blade tip to thereby increase an energy capture power coefficient of the wind turbine.

Abstract: Vertical and horizontal wind shears, yaw misalignment and/or turbulence act together to produce asymmetric loading across a wind turbine rotor. The resultant load produces bending moments in the blades that are reacted through the hub and subsequently to the low-speed shaft. As a result, the main shaft and main shaft flange are displaced from their at rest or non-aerodynamic load positions. The amount of shaft flange displacement is measured using one or more sensors. The output signals from the sensors are used to determine the magnitude and/or the orientation of the resultant rotor load. This information is used to effect the blade pitch change needed to reduce the load and thereby reduce fatigue and loading on various turbine components.