US 12,140,117 B2
Detecting rotor blade clearance in a wind turbine using doppler shift and a mathematical model
Eirik Nagel, Flensburg (DE)
Assigned to SIEMENS GAMESA RENEWABLE ENERGY A/S, Brande (DK)
Appl. No. 17/598,960
Filed by Siemens Gamesa Renewable Energy A/S, Brande (DK)
PCT Filed Mar. 16, 2020, PCT No. PCT/EP2020/057067
§ 371(c)(1), (2) Date Sep. 28, 2021,
PCT Pub. No. WO2020/200723, PCT Pub. Date Oct. 8, 2020.
Claims priority of application No. 19166597 (EP), filed on Apr. 1, 2019.
Prior Publication US 2022/0195992 A1, Jun. 23, 2022
Int. Cl. F03D 7/02 (2006.01); F03D 17/00 (2016.01)
CPC F03D 17/00 (2016.05) [F03D 7/0288 (2013.01); F05B 2260/84 (2013.01); F05B 2270/17 (2013.01); F05B 2270/33 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of determining a blade clearance during operation of a wind turbine, the blade clearance corresponding to a distance between a rotor blade and a tower of the wind turbine, the method comprising:
detecting a rotor blade velocity;
emitting a first signal from an observer location, the first signal having a first frequency;
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;
determining a Doppler shift of the second signal relative to the first signal; and
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.