	US 12,012,934 B2
	System and method for controlling blade pitch on wind turbine rotor blades to reduce vibrations and limit loads in a locked condition of the turbine rotor
Valentina Motta, Berlin (DE); Darren John Danielsen, Simpsonville, SC (US); Marianne Luise Susanne Hartung, Munich (DE); Martin Stettner, Munich (DE); and Nikolai N. Pastouchenko, Latham, NY (US)
Assigned to General Electric Renovables Espana, S.L., Barcelona (ES)
Filed by General Electric Renovables Espana, S.L., Barcelona (ES)
Filed on Dec. 8, 2021, as Appl. No. 17/544,989.
Prior Publication US 2023/0175487 A1, Jun. 8, 2023
Int. Cl. F03D 7/02 (2006.01); F03D 7/04 (2006.01); F03D 17/00 (2016.01)

CPC F03D 7/0296 (2013.01) [F03D 7/0224 (2013.01); F03D 7/0298 (2023.08); F03D 7/045 (2013.01); F03D 17/00 (2016.05); F03D 7/024 (2013.01); F05B 2260/70 (2013.01); F05B 2260/821 (2013.01); F05B 2260/96 (2013.01); F05B 2270/32 (2013.01); F05B 2270/321 (2013.01); F05B 2270/328 (2013.01); F05B 2270/334 (2013.01)]

10 Claims

1. A proactive method for reducing vibrations in one or more rotor blades of a wind turbine when the wind turbine is in a standstill condition with a rotor hub locked against rotation, the method comprising:

determining one or more wind parameters for wind impacting the rotor blades;

determining an initial blade orientation of the rotor blades to an incoming wind direction;

based on the one or more wind parameters and the initial blade orientation, determining an angle of attack for the rotor blades that will at least reduce vibrations induced in the rotor blades from the wind;

with a controller, pitching the rotor blades to achieve the angle of attack using an auxiliary drive system in the wind turbine;

wherein the angle of attack is determined and the rotor blades are pitched from the initial blade orientation to the angle of attack prior to vibrations being induced in the rotor blades; and

determining that yaw control is unavailable for the rotor hub prior to determining the angle of attack or prior to pitching the rotor blades to the angle of attack; and

wherein the one or more wind parameters comprise wind speed and wind direction, and further comprising determining that the wind speed is above a threshold level as a prerequisite to determining the angle of attack or prior to pitching the rotor blades to the angle of attack, and after the wind speed is determined to be above the threshold level, further comprising determining the wind direction and using the wind direction to determine the angle of attack.

6. A wind turbine, comprising:

rotor blades on a rotatable rotor hub;

one or more sensors located to detect wind parameters of wind impacting the rotor blades;

a pitch system configured to change a pitch angle of the rotor blades;

a controller in operable communication with the pitch system;

wherein with the rotor hub locked against rotation, the controller is configured to:

determine values of the wind parameters for the wind impacting the rotor blades;

determine an initial blade orientation to an incoming wind direction;

based on the wind parameters, determine an angle of attack for the rotor blades that will at least reduce vibrations induced in the rotor blades from the wind;

control the pitch system to pitch the rotor blades to the angle of attack;

determine that yaw control is unavailable for the rotor hub prior to determining the angle of attack or prior to pitching the rotor blades to the angle of attack;

wherein the angle of attack is determined and the rotor blades are pitched from the initial blade orientation to the angle of attack prior to vibrations being induced in the rotor blades; and

wherein the one or more wind parameters comprise wind speed and wind direction, the controller further configured to determine that the wind speed is above a threshold level as a prerequisite to determining the angle of attack or prior to pitching the rotor blades to the angle of attack, and after the wind speed is determined to be above the threshold level, to determine the wind direction and use the wind direction to determine the angle of attack.