| 摘要 |
The invention relates to an optical detector for determining the relative wind direction (attack angle) relative to a rotating or stationary wind turbine rotor. The optical detector comprises an output part which transmits distinguishable light beams out from a rotor blade in different predetermined directions. The beams may be distinguishable by light color, by the time the individual beams are emitted and/or by different amplitude modulation frequencies or other modulations of the individual beams. By determining pulse times of scattered light from wind borne particles moving in or through the different distinguishable beams, or determining the number of pulses within a period, it is possible to determine the relative wind direction or angle of attach as the predetermined direction of a beam which has the longest pulse times or the fewest number of pulses within a given period of time. |
