摘要 |
A wind of the type having a tower and a nacelle with a rotor rotatably connected to the nacelle for rotating about a rotor axis and having a plurality of equally spaced blades has the rotor balanced by firstly taking a measurement of torsional vibration and then by using photographic techniques to analyze dynamic imbalance caused by differences in the angle of attack of the blades. The torsional vibration is detected using two sensors at positions mirrored exactly in distance to the left and right of the rotor axis and detecting vibration in the axial direction. The angle of attack is measured by analyzing images of the tip of the blade where, during the analysis, distortion in angles at different locations in the image are corrected, in dependence upon a prior analysis of an image taken by the camera relative to a known image. |