Detecting rotor blade clearance in a wind turbine using doppler shift and a mathematical model

Abstract

A method of determining a blade clearance during operation of a wind turbine is provided, the blade clearance corresponding to a distance between a rotor blade and a tower of the wind turbine. The method includes (a) detecting a rotor blade velocity, (b) emitting a first signal from an observer location, the first signal having a first frequency, (c) receiving a second signal at the observer location, the second signal being reflected from the rotor blade when the first signal impinges on the rotor blade, (d) determining a Doppler shift of the second signal relative to the first signal, and (e) determining the blade clearance based on the first frequency, the Doppler shift, the observer location, and the rotor blade velocity, wherein the step of determining the blade clearance utilizes a mathematical model. A corre-sponding system and a wind turbine comprising such a system are also provided.

Dependencies are inferred from the claim text.