Method of operating a wind turbine yaw assembly
The disclosed describes a method of operating a wind turbine yaw assembly comprising a yaw ring and a number of yaw drive units, wherein a yaw drive unit comprises a pinion arranged to engage with the yaw ring, which method comprises the steps of identifying a damaged tooth on the yaw ring; providing damage descriptor parameters to the yaw drive controller; and controlling a yaw drive unit on the basis of the damage descriptor parameters to reduce the force exerted by its pinion on a damaged tooth. The disclosed further describes a wind turbine yaw assembly, a wind turbine, and a computer program product.
1. A method of operating a wind turbine yaw assembly comprising a yaw ring and a number of yaw drive units, wherein a yaw drive unit comprises a pinion arranged to engage with the yaw ring, which method comprises the steps of
identifying a damaged tooth on the yaw ring;
providing damage descriptor parameters to a yaw drive controller; and
controlling a yaw drive unit on the basis of the damage descriptor parameters to reduce the force exerted by its pinion on a damaged tooth.
2. The method according to claim 1 , wherein the step of controlling a yaw drive unit to reduce the force exerted by its pinion on the damaged tooth comprises reducing the rotational speed of a motor of the yaw drive unit.
3. The method according to claim 1 , wherein the step of controlling a yaw drive unit to reduce the force exerted by its pinion on the damaged tooth comprises reducing the torque of the motor of that yaw drive unit to at most 5%, more preferably at most 1%, of full torque.
4. The method according to claim 1 , wherein the step of reducing the force exerted by a pinion on a damaged tooth is carried out during a yawing procedure of the nacelle and/or during a braking procedure.
5. The method according to claim 1 , wherein the step of identifying a damaged tooth comprises establishing the position of a damaged tooth relative to a reference position of the yaw assembly.
6. The method according to claim 5 , wherein a reference position defines an initial position of a yaw bedframe supporting the yaw drive units.
7. The method according to claim 5 , wherein the reference position comprises a north reference of the yaw ring, which north reference is aligned with the yaw bedframe reference position in an initial position of the yaw assembly.
8. The method according to claim 1 , wherein the step of identifying a damaged tooth comprises establishing a damage severity parameter describing the extent of damage of the damaged tooth.
9. A wind turbine yaw assembly arranged at an interface between a nacelle and a tower of a wind turbine, and comprising
a yaw ring with an annular arrangement of teeth;
a number of yaw drive units, wherein a yaw drive unit comprises a motor and a pinion arranged to engage with teeth of the yaw ring;
a yaw drive controller adapted to control the motor of a yaw drive unit to effect a rotation of the nacelle relative to the tower;
wherein
a damage descriptor input for providing damage descriptor parameters to the yaw drive controller, and wherein the yaw drive controller is further adapted to reduce the force exerted by a pinion of a yaw drive unit on a damaged tooth on the basis of the damage descriptor parameters.
10. The wind turbine yaw assembly according to claim 9 , comprising a redundant arrangement of yaw drive units.
11. The wind turbine yaw assembly according to claim 9 , wherein a yaw drive unit comprises a passive brake assembly.
12. The wind turbine comprising a yaw assembly according to claim 9 .
13. A computer program product, comprising a computer readable hardware storage device having computer readable program code stored therein, said program code executable by a processor of a computer system to implement a method comprising a computer program that is directly loadable into a memory of a controller of a wind turbine yaw assembly and which comprises program elements for performing steps of the method according to claim 1 when the computer program is executed by the controller of the wind turbine yaw assembly.
14. A computer program product, comprising a computer readable hardware storage device having computer readable program code stored therein, said program code executable by a processor of a computer system to implement a method according to claim 13 , comprising program elements realized to receive a damage severity parameter and to adjust the control signals of a yaw drive unit on the basis of the damage severity parameter.
15. A computer program product, comprising a computer readable hardware storage device having computer readable program code stored therein, said program code executable by a processor of a computer system to implement a method according to claim 13 , comprising program elements realized to identify a yaw ring region containing a damaged tooth and to adjust control signals of a yaw drive unit as the yaw drive unit passes that region of the yaw ring.