US 11,668,279 B2
Controlling wind turbines in presence of wake implications
Per Egedal, Herning (DK); and Pieter M. O. Gebraad, København (DK)
Assigned to SIEMENS GAMESA RENEWABLE ENERGY A/S, Brande (DK)
Appl. No. 17/273,380
Filed by Siemens Gamesa Renewable Energy A/S, Brande (DK)
PCT Filed Sep. 6, 2019, PCT No. PCT/EP2019/073860
§ 371(c)(1), (2) Date Mar. 4, 2021,
PCT Pub. No. WO2020/053096, PCT Pub. Date Mar. 19, 2020.
Claims priority of application No. 18193507 (EP), filed on Sep. 10, 2018.
Prior Publication US 2021/0207580 A1, Jul. 8, 2021
Int. Cl. F03D 7/02 (2006.01); F03D 7/04 (2006.01)
CPC F03D 7/0204 (2013.01) [F03D 7/048 (2013.01); F05B 2270/329 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for controlling a first wind turbine of a plurality of wind turbines of a wind park, wherein a second wind turbine of the plurality of wind turbines can be affected by a wake region caused by the first wind turbine which is positioned upstream of the second wind turbine,
the method comprising:
determining a current yaw state, wherein the current yaw state is selected from at least one of:
a) an actual rotor yaw misalignment angle of the first wind turbine, wherein the actual rotor yaw misalignment angle is defined as an angle between a rotating axis of a rotor of the first wind turbine and a current wind direction at the first wind turbine;
b) an identifier representing whether the actual rotor yaw misalignment angle is either in a range of positive yaw misalignment angles or alternatively of negative yaw misalignment angles;
determining a wind condition indicative of a level of potential wake inducement at the second wind turbine caused at least by the first wind turbine, the level of wake inducement being at least represented by a distance between locations of the first wind turbine and the second wind turbine and/or by the current wind direction at the first wind turbine; and
defining a rotor yaw offset angle set point for the first wind turbine based on the current yaw state, the wind condition, and at least one yaw angle hysteresis switching threshold, such that the rotor yaw offset angle set point follows a hysteresis, thereby avoiding immediate consecutive switching between a range of positive yaw offset angles and negative yaw offset angles;
the method further comprising:
wherein the step of defining the rotor yaw offset angle set point following a hysteresis is defined by the substeps of: switching an actual rotor yaw misalignment angle with a positive angle to a negative angle if a first one of the at least one yaw angle hysteresis switching threshold is reached, and switching an actual rotor yaw misalignment angle with negative angle to a positive angle if a second one of the at least one yaw angle hysteresis switching threshold is reached; and/or
wherein the at least one yaw angle hysteresis switching threshold defines at least a first hysteresis limit for the rotor yaw offset angle set point or the wind direction such that the rotor yaw offset angle set point is limited to an incremental angle difference in case the rotor yaw offset angle set point or the wind direction is below the first hysteresis limit and is switched between positive and negative angle thereby reversing a rotor yaw misalignment angle in case the rotor yaw offset angle set point or the wind direction reaches or would exceed the first hysteresis limit.