Abstract: The invention relates to a method and a device for monitoring the state of rotor blades on wind power installations. According to the invention, structure-borne noise is measured by means of at least one displacement sensor arranged on the rotor blade, the output signals of said sensors determine a frequency spectrum in an evaluation unit by means of suitable methods, the frequency spectrum is compared to reference spectra corresponding to defined states of damage and other particular states and stored in the evaluation unit, and the state of the rotor blade is determined therefrom. The aim of the invention is to provide a method and a device which enable existing local inner and outer damage, and other particular damage-causing states of the rotor blades, to be rapidly identified and evaluated, in order to take into account the effect thereof on the operation of the installation in an automatic manner.

Abstract: The invention relates to a method and a device for monitoring the state of rotor blades on wind power installations. According to the invention, structure-borne noise is measured by means of at least one displacement sensor arranged on the rotor blade, the output signals of said sensors determine a frequency spectrum in an evaluation unit by means of suitable methods, the frequency spectrum is compared to reference spectra corresponding to defined states of damage and other particular states and stored in the evaluation unit, and the state of the rotor blade is determined therefrom. The aim of the invention is to provide a method and a device which enable existing local inner and outer damage, and other particular damage-causing states of the rotor blades, to be rapidly identified and evaluated, in order to take into account the effect thereof on the operation of the installation in an automatic manner.

Abstract: The invention relates to a method and a device for controlling the pitch angles of rotor blades on wind power stations, the pitch angle being controlled to maximize yields and prevent excess loads on the rotor blades. The aim of the invention is to maximize the propulsive power on rotor blades. Said aim is achieved by taking a first measurement of the pressure prevailing on the pressure side (5) and a second measurement of the pressure prevailing on the suction side (6) of a rotor blade (1), determining the difference in pressure between the first and second pressure measurement, and adjusting the pitch angle in accordance with the ratio between the first and second pressure measurement.