Controlling the damping of sidewards tower oscillations based on a power oscillation disturbance level

A control system for controlling at least one wind turbine of a group of wind turbines of a wind park commonly supplying electric energy to an electrical grid, each wind turbine comprises a damping controller for determining a damping control signal for counteracting a sidewards tower oscillation, the control system comprising a processing unit being arranged to perform an operation, comprising:

• determining a power oscillation disturbance level of at a point of measurement of the electrical grid;
• determining a grid condition level at the point of measurement of the electrical grid;
• determining a disturbance severity based on the power oscillation disturbance level and the grid condition level;
• upon receiving a request to reduce the power oscillation disturbance level at the point of measurement of the electrical grid from a system operator, operate the group of wind turbines of the wind park to reduce the power oscillation disturbance level based on the disturbance severity.