Devices and methods for mitigating vibrations in wind turbines

A wind turbine, comprising:

• a tower;
• a nacelle;
• a hub with one or more blades;
• at least one of the blades comprising a vibration mitigating device arranged around the blade, the vibration mitigating device comprising:
• a main body extending chord-wise around and encircling the blade, the main body comprising at least one inflatable body;
• a plurality of inflatable air flow modifying elements extending radially outward from the main body;
• a sensor system that monitors a condition of the wind turbine or an environmental condition around the wind turbine;
• a pressure source connected to the at least one inflatable body and the inflatable airflow modifying elements, the pressure source located in the wind turbine or in the vibration mitigating device;
• wherein the pressure source is configured to regulate an inflation level of the at least one inflatable body and the air flow modifying elements such that the inflation level is controlled based on variations or changing circumstances detected by the sensor system;
• and
• wherein the at least one inflatable body comprises a longitudinal length in a span-wise direction of the blade, the plurality of inflatable air flow modifying elements configured as inflatable plates extending radially outward from the at least one inflatable body and extending completely along the longitudinal length of the at least one inflatable body.

A method for mitigating vibrations of a parked wind turbine, the method comprising;

• arranging a vibration mitigating device around at least one blade of the parked wind turbine, the vibration mitigating device comprising;
• a main body extending chord-wise around and encircling the blade, the main body including at least one inflatable body;
• a plurality of inflatable air flow modifying elements extending radially outward from the main body;
• the at least one inflatable body comprising a longitudinal length in a span-wise direction of the blade, the plurality of inflatable air flow modifying elements configured as inflatable plates extending radially outward from the at least one inflatable body and extending completely along the longitudinal length of the at least one inflatable body;
• a pressure source connected to the at least one inflatable body and the plurality of airflow modifying elements;
• with a sensor system, monitoring a condition of the wind turbine or an environmental condition around the wind turbine;
• and
• regulating an inflation level of the at least one inflatable body and the air flow modifying elements by inflating or deflating the at least one inflatable body and the air flow modifying elements by an amount based on variations or changing circumstances detected by the sensor system.

A method for mitigating vibrations of a parked wind turbine, the method comprising:

• releasably positioning a vibration mitigating device chord-wise around a blade of the wind turbine, the vibration mitigating device comprising a main body configured to extend chord-wise around and encircle the blade, the main body comprising at least one inflatable body and a plurality of inflatable airflow modifying elements extending radially outward from the main body, wherein the at least one inflatable body comprise a longitudinal length in a span-wise direction of the blade and the plurality of inflatable air flow modifying elements are configured as inflatable plates extending radially outward from the at least one inflatable body and extending completely along the longitudinal length of the at least one inflatable body;
• inflating the at least one inflatable body and the plurality of airflow modifying elements to secure the vibration mitigating device around the blade;
• monitoring wind turbine loading;
• and
• based on the wind turbine loading, regulating an inflation state of the at least one inflatable body and the plurality of airflow modifying elements such that an inflation level thereof is controlled based on variations or changes in the wind turbine loading detected by the sensor system.

A wind turbine, comprising:

• a tower;
• a nacelle;
• a hub with one or more blades;
• at least one of the blades comprising a vibration mitigating device arranged around the blade, the vibration mitigating device comprising:
• a main body extending chord-wise around and encircling the blade, the main body comprising at least one inflatable body;
• a plurality of inflatable air flow modifying elements extending radially outward from the main body;
• a sensor system that monitors a condition of the wind turbine or an environmental condition around the wind turbine;
• a pressure source connected to the at least one inflatable body and the inflatable airflow modifying elements, the pressure source located in the wind turbine or in the vibration mitigating device;
• wherein the pressure source is configured to regulate an inflation level of the at least one inflatable body and the air flow modifying elements such that the inflation level is controlled based on variations or changing circumstances detected by the sensor system;
• and
• wherein the main body includes a plurality of the inflatable bodies having different cross-sectional shapes, the pressure source comprising a dedicated pressure device for each of the individual inflatable bodies.