Method and device for monitoring the state of rotor blades on wind power installations
First Claim
1. A method for monitoring the state of rotor blades on wind power installations comprising;
- measuring structure-borne noise of at least one rotor blade with at least one sensor fastened on the rotor blade such that the at least one sensor rotates with the at least one rotor blade,the at least one sensor is connected to a unit for wireless transmission of the output signals of the sensors to an evaluation unit that comprises a central computer unit and storage devices,the output signals of the at least one sensor being wirelessly transmitted to the evaluation unit where, from the signals a frequency spectrum is determined,the frequency spectrum is compared with parameterized 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,a structure-borne noise is measured from a sequence of several individual measurements carried out directly one after the other by the at least one sensor, the beginning of each of said individual measurements being triggered according to a uniform rotational angle of the rotor blade in relation to the rotational axis of the rotor;
all of the determined frequency spectra of each individual measurement being accumulated to determine the frequency spectrum before being compared with the reference spectra;
the reference spectra parameterized by means of at least one of meteorological and installation-specific data; and
the parameters of the reference spectra determined in an up-to-date manner in parallel with the structure-borne noise measurement by means of additional measurements and transferred to the evaluation unit.
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Accused Products
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. To this end, structure-borne noise is measured from a sequence of individual measurements carried out directly one after the other, the beginning of each of said individual measurements being triggered according to a uniform rotational angle of the rotor blade in relation to the rotational axis of the rotor, and all of the determined frequency spectra of each individual measurements are accumulated before being compared with the reference spectra.
53 Citations
35 Claims
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1. A method for monitoring the state of rotor blades on wind power installations comprising;
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measuring structure-borne noise of at least one rotor blade with at least one sensor fastened on the rotor blade such that the at least one sensor rotates with the at least one rotor blade, the at least one sensor is connected to a unit for wireless transmission of the output signals of the sensors to an evaluation unit that comprises a central computer unit and storage devices, the output signals of the at least one sensor being wirelessly transmitted to the evaluation unit where, from the signals a frequency spectrum is determined, the frequency spectrum is compared with parameterized 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, a structure-borne noise is measured from a sequence of several individual measurements carried out directly one after the other by the at least one sensor, the beginning of each of said individual measurements being triggered according to a uniform rotational angle of the rotor blade in relation to the rotational axis of the rotor; all of the determined frequency spectra of each individual measurement being accumulated to determine the frequency spectrum before being compared with the reference spectra; the reference spectra parameterized by means of at least one of meteorological and installation-specific data; and the parameters of the reference spectra determined in an up-to-date manner in parallel with the structure-borne noise measurement by means of additional measurements and transferred to the evaluation unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A method for monitoring the state of rotor blades on wind power installations comprising;
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measuring structure-borne noise of at least one rotor blade with at least one sensor fastened on the rotor blade such that the at least one sensor rotates with the at least one rotor blade, the at least one sensor is connected to a unit for wireless transmission of the output signals of the sensors to an evaluation unit that comprises a central computer unit and storage devices, the output signals of the at least one sensor being wirelessly transmitted to the evaluation unit where, from the signals a frequency spectrum is determined, the frequency spectrum is compared with parameterized 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, a structure-borne noise is measured from a sequence of several individual measurements carried out directly one after the other by the at least one sensor, the beginning of each of said individual measurements being triggered according to a uniform rotational angle of the rotor blade in relation to the rotational axis of the rotor, all of the determined frequency spectra of each individual measurement being accumulated to determine the frequency spectrum before being compared with the reference spectra; and wherein synchronized measurements of all rotor blades of a wind power installation are performed and the state change of a rotor blade is determined from the difference of the accumulated frequency spectra of all rotor blades and the comparison of the difference spectrum with reference spectra.
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35. A method for monitoring the state of rotor blades on wind power installations comprising;
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measuring structure-borne noise of at least one rotor blade with at least one sensor fastened on the rotor blade such that the at least one sensor rotates with the at least one rotor blade, the at least one sensor is connected to a unit for wireless transmission of the output signals of the sensors to an evaluation unit that comprises a central computer unit and storage devices, the output signals of the at least one sensor being wirelessly transmitted to the evaluation unit where, from the signals a frequency spectrum is determined, the frequency spectrum is compared with parameterized 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, a structure-borne noise is measured from a sequence of several individual measurements carried out directly one after the other by the at least one sensor, the beginning of each of said individual measurements being triggered according to a uniform rotational angle of the rotor blade in relation to the rotational axis of the rotor, and all of the determined frequency spectra of each individual measurement being accumulated to determine the frequency spectrum before being compared with the reference spectra; and wherein the reference spectra are determined from statistically evaluated and equivalence-assessed frequency spectra of preceding structure-borne noise measurements of the relevant rotor blade.
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Specification