US 12,135,012 B2
Reduction of edgewise vibrations using blade load signal
Jesper Sandberg Thomsen, Hadsten (DK); Morten Bro, Aalborg (DK); and Ian Couchman, Horley (GB)
Assigned to VESTAS WIND SYSTEMS A/S, Aarhus N (DK)
Appl. No. 17/615,060
Filed by VESTAS WIND SYSTEMS A/S, Aarhus N (DK)
PCT Filed May 26, 2020, PCT No. PCT/DK2020/050147
§ 371(c)(1), (2) Date Nov. 29, 2021,
PCT Pub. No. WO2020/239177, PCT Pub. Date Dec. 3, 2020.
Claims priority of application No. PA 2019 70335 (DK), filed on May 28, 2019.
Prior Publication US 2022/0220936 A1, Jul. 14, 2022
Int. Cl. F03D 7/00 (2006.01); F03D 7/02 (2006.01)
CPC F03D 7/0224 (2013.01) [F03D 7/0296 (2013.01); F05B 2260/966 (2013.01); F05B 2270/328 (2013.01); F05B 2270/331 (2013.01); F05B 2270/334 (2013.01); F05B 2270/342 (2020.08); F05B 2270/703 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A rotor control system for actuating pitch of pitch adjustable rotor blades of a wind turbine, the rotor control system comprising:
a pitch actuating unit for determining a pitch modification signal to be applied to a pitch actuator for actuating the pitch of the pitch adjustable rotor blades; the pitch actuation unit being arranged to:
receive an edgewise load signal for each of the pitch adjustable rotor blades, the edgewise load signal being measured in a rotating reference frame;
apply an m-blade coordinate transformation to the edgewise load signal to transform the edgewise load signal to a whirling reference frame along a first and a second reference direction;
select a signal component of either the first or the second reference direction to obtain a selected signal component;
filter the selected signal component at either a backward whirling frequency or a forward whirling frequency to obtain a filtered signal component;
apply an inverse m-blade coordinate transformation to the filtered signal component to obtain the pitch modification signal, wherein only a whirling mode of either backward or forward whirling is targeted in obtaining the pitch modification signal; and
apply the pitch modification signal to the pitch actuator.