Method and device for determining a bending angle of a rotor blade of a wind turbine system

Abstract

A method for determining a bending angle of a rotor blade of a wind turbine system includes step of reading in an acceleration signal which represents an acceleration of the rotor blade acting essentially perpendicularly with respect to a rotor plane. In addition, the method includes a step of determining the bending angle of the rotor blade of the wind turbine using the acceleration signal.

1 . A method for determining a bending angle of a rotor blade of a wind turbine system comprising:
 reading in at least one acceleration signal that represents a first acceleration acting on the rotor blade in a fashion substantially perpendicular to a rotor plane; and   determining the bending angle of the rotor blade of the wind turbine system by using the at least one acceleration signal.   
     
     
         2 . The method as claimed in  claim 1 , wherein:
 reading in the at least one acceleration signal includes acquiring an acceleration profile,   determining the bending angle of the rotor blade includes determining a spectrum from the acceleration profile, and   determining the bending angle includes using the determined spectrum.   
     
     
         3 . The method as claimed in  claim 2 , wherein:
 determining the bending angle of the rotor blade includes comparing the determined spectrum with a provided spectrum, and using a result of the comparison.   
     
     
         4 . The method as claimed in  claim 2 , wherein reading in the at least one acceleration signal includes actively exciting vibration of the rotor blade. 
     
     
         5 . The method as claimed in  claim 1 , wherein determining the bending angle of the rotor blade includes subjecting the at least one acceleration signal to at least one of lowpass filtering and Kalman filtering. 
     
     
         6 . The method as claimed in  claim 1 , wherein:
 determining the bending angle includes using an information item relating to at least one of:
 a distance of a first acceleration sensor providing the at least one acceleration signal from a rotor axis, 
 an inclination angle of the rotor axis from horizontal, and 
 an acceleration of a tower head of the wind turbine system, and 
   determining the bending angle includes using an information item relating to rotational speed and rotary position of a rotor.   
     
     
         7 . The method as claimed in  claim 1 , wherein determining the bending angle includes considering a time profile of the first acceleration at a position of the rotor blade. 
     
     
         8 . The method as claimed in  claim 6 , further comprising reading in a further acceleration signal that represents a second acceleration, acting substantially in a longitudinal direction of the rotor blade, at a location of the first acceleration sensor, wherein determining a bending angle of the rotor blade of the wind turbine system includes using the further acceleration signal. 
     
     
         9 . The method as claimed in  claim 1 , further comprising one of:
 determining individual incidence angles of the rotor blades based on the bending angle, and   determining individual incidence angles of the rotor blades based on loading, determined from the bending angle, of the rotor blade or the rotor blades.   
     
     
         10 . A device for determining a bending angle of a rotor blade of a wind turbine system, the device comprising:
 an interface configured to read in at least one acceleration signal that represents an acceleration acting on the rotor blade, and   a unit configured to determine the bending angle of the rotor blade of the wind turbine system by using the acceleration signal.   
     
     
         11 . A computer program product having program code for carrying out a method for determining the bending angle of a rotor blade of a wind turbine system, the computer program product comprising:
 a mechanism configured to read in at least one acceleration signal that represents a first acceleration acting on the rotor blade in a fashion substantially perpendicular to a rotor plane; and   a mechanism configured to determine the bending angle of the rotor blade of the wind turbine system by using the at least one acceleration signal, wherein the computer program product is configured to determine the bending angle when the program is executed on one of a control unit and a device.