DETERMINATION OF A VIBRATIONAL FREQUENCY OF A WIND TURBINE ROTOR BLADE WITH A SENSOR DEVICE BEING PLACED AT A STRUCTURAL COMPONENT BEING ASSIGNED TO AND/OR BEING PART OF THE ROTOR

摘要

It is described a system for determining a vibrational frequencyof a blade (112a) being attached to a structuralcomponent (110) being assigned to and/or being part of arotor of a wind turbine (100), wherein the blade (112a) isvibrating within a rotational plane of the rotor. The systemcomprises (a) a sensor device (120) being sensitive to amovement along a first sensor direction (x), wherein thesensor device (120) is placeable at the structural component(110) such that the first sensor direction (x) and the directionof the longitudinal extension of the blade (112a) have afirst fixed angular relationship with respect to each otherand wherein the sensor device (120) is configured to providea first sensor output signal (a_x) being indicative for themovement of the structural component (110) along the firstsensor direction (x). The system further comprises a dataprocessing unit (130, 230) being connected with the sensordevice (120), wherein the data processing device (130, 230)is configured to determine the vibrational frequency of theblade (112a) based on the first sensor output signal (a_x)and on the first fixed angular relationship. It is furtherdescribed a corresponding method for determining a vibrationalfrequency of a blade (112a) and a computer program forcontrolling such a method. Further, it is described a windturbine (100) being equipped with such a system for determininga vibrational frequency of a blade (112a).