Abstract: A system and method are provided for controlling a wind turbine based on a collective pitch-offset. Accordingly, a wind condition acting on a rotor of the wind turbine is determined, and a first collective pitch angle for the plurality of rotor blades is set, and the wind turbine is operated. A thrust of the rotor based, at least in part, on the wind condition is determined, and an actual collective pitch angle is calculated. A collective pitch offset is determined based on the difference between the first collective pitch angle and the actual collective pitch angle. The collective pitch offset is integrated with at least one pitch setpoint command. The at least one pitch setpoint command is transmitted to a pitch control mechanism of the wind turbine.

Abstract: A method for mitigating loads acting on a rotor blade of a wind turbine includes determining, via a state estimator of a controller, a blade state estimation of the rotor blade. The method also includes reconstructing, via the controller, one or more loading signals of the rotor blade from the blade state estimation using modal analysis such that the loading signal(s) include a lead time. Further, the method includes comparing the loading signal(s) of the rotor blade to a loading threshold. Moreover, the method includes implementing a control action based on the comparison such that the lead time provided by the loading signal(s) allows the control action to take effect before a damaging load occurs on the rotor blade.

Abstract: A system and method are provided for controlling a wind turbine based on a collective pitch-offset. Accordingly, a wind condition acting on a rotor of the wind turbine is determined, and a first collective pitch angle for the plurality of rotor blades is set, and the wind turbine is operated. A thrust of the rotor based, at least in part, on the wind condition is determined, and an actual collective pitch angle is calculated. A collective pitch offset is determined based on the difference between the first collective pitch angle and the actual collective pitch angle. The collective pitch offset is integrated with at least one pitch setpoint command. The at least one pitch setpoint command is transmitted to a pitch control mechanism of the wind turbine.

Abstract: A method for controlling loads of a wind turbine includes receiving sensor signals from one or more sensors being indicative of a movement of a nacelle of the wind turbine from a reference point. More particularly, the movement corresponds, at least, to a tilt and/or a displacement of the wind turbine tower and/or nacelle. The method also includes generating a deflection profile of the tower along its overall length from a bottom end to a top end thereof based on the sensor signals. Further, the method includes determining at least one of a thrust or a tower load of the wind turbine from the deflection profile. In addition, the method includes implementing a control action for the wind turbine based on the thrust and/or the tower load.

Abstract: A method for controlling loads of a wind turbine includes receiving sensor signals from one or more sensors being indicative of a movement of a nacelle of the wind turbine from a reference point. More particularly, the movement corresponds, at least, to a tilt and/or a displacement of the wind turbine tower and/or nacelle. The method also includes generating a deflection profile of the tower along its overall length from a bottom end to a top end thereof based on the sensor signals. Further, the method includes determining at least one of a thrust or a tower load of the wind turbine from the deflection profile. In addition, the method includes implementing a control action for the wind turbine based on the thrust and/or the tower load.

Abstract: A method for operating a wind turbine. The method includes providing a wind turbine having at least one blade having adjustable pitch angle that is adjusted according to an operational parameter schedule. A blade efficiency parameter is determined in response to a wind speed and a rotor speed. A minimum pitch angle is determined in response to the blade efficiency parameter and the pitch angle of the at least one blade in response to the blade efficiency parameter is maintained to an angle equal to or greater than the minimum pitch angle independent of the operational parameter schedule. A wind turbine plant and a method for servicing a wind turbine are also disclosed.

Abstract: A method of controlling a wind turbine that includes at least one rotor shaft and at least one blade operatively coupled to the rotor shaft includes measuring a first wind turbine operational condition that is representative of a blade deflection value and generating a first operational condition signal based on that first wind turbine operational condition. The wind turbine also includes a drive train including at least one rotor shaft and an electric generator. The method also includes measuring at least one second wind turbine operational condition and generating at least one second operational condition signal. The method further includes changing the blade deflection value by changing the second operational condition.

Abstract: A method for monitoring wear of a blade pitch brake within a rotor blade pitch control system of a wind turbine is described. The rotor blade pitch control system includes a blade pitch actuator. The method includes engaging the blade pitch brake and measuring a blade pitch displacement while the blade pitch brake is engaged. The method further includes determining a brake wear level based on the measured blade pitch displacement while the blade pitch brake is engaged, and generating a brake wear level output signal corresponding to the brake wear level.

Abstract: A method for monitoring wear of a blade pitch brake within a rotor blade pitch control system of a wind turbine is described. The rotor blade pitch control system includes a blade pitch actuator. The method includes engaging the blade pitch brake and measuring a blade pitch displacement while the blade pitch brake is engaged. The method further includes determining a brake wear level based on the measured blade pitch displacement while the blade pitch brake is engaged, and generating a brake wear level output signal corresponding to the brake wear level.

Abstract: A method of controlling a wind turbine that includes at least one rotor shaft and at least one blade operatively coupled to the rotor shaft includes measuring a first wind turbine operational condition that is representative of a blade deflection value and generating a first operational condition signal based on that first wind turbine operational condition. The wind turbine also includes a drive train including at least one rotor shaft and an electric generator. The method also includes measuring at least one second wind turbine operational condition and generating at least one second operational condition signal. The method further includes changing the blade deflection value by changing the second operational condition.

Abstract: A method for operating a wind turbine. The method includes providing a wind turbine having at least one blade having adjustable pitch angle that is adjusted according to an operational parameter schedule. A blade efficiency parameter is determined in response to a wind speed and a rotor speed. A minimum pitch angle is determined in response to the blade efficiency parameter and the pitch angle of the at least one blade in response to the blade efficiency parameter is maintained to an angle equal to or greater than the minimum pitch angle independent of the operational parameter schedule. A wind turbine plant and a method for servicing a wind turbine are also disclosed.

Abstract: In one embodiment, the data storage media can comprise: a substrate, a data layer, and a reflective layer disposed between the data layer and the substrate. The substrate can comprise a substrate material selected from the group consisting of polyphenylene ether, blends comprising polyphenylene ether, copolymers comprising polyphenylene ether, mixtures comprising polyphenylene ether, reaction products of a compostion comprising polyphenylene ether, and composites comprising polyphenylene ether. The data layer can comprise a material selected from the group consisting of organic dye and inorganic phase change materials. The storage media can comprise imprinted features. In another embodiment, the first surface data storage media can comprise: a substrate, a reflective layer on a first side of the substrate, and a protective layer disposed on a side of the substrate opposite the first side. The protective layer can comprise silicon dioxide. The first surface data storage media comprises imprinted features.