Method for operating a wind turbine, control system and wind turbine

A method for operating a wind turbine having a rotor with at least one rotor blade, a tower, and a pitch setting system for setting a pitch angle of the at least one rotor blade, the method comprising:

• providing first information which is representative for a tilt bending moment acting on the rotor;
• providing second information which is representative for a thrust force acting on the rotor;
• providing third information which is representative for a critical area of thrust forces and tilt bending moments;
• determining fourth information depending on the first information, the second information, and the third information which is representative for whether the tilt bending moment and the thrust force lie within the critical area;
• and,
• if the tilt bending moment and the thrust force lie within the critical area, generating an output signal configured to cause the pitch setting system to change the pitch angle of the at least one rotor blade in order to leave the critical area.

A control system for operating a wind turbine having a rotor with at least one rotor blade, a tower and a pitch setting system for setting the pitch angle of the at least one rotor blade, the control system comprising:

• a first sensor system configured to take measurements via which a tilt bending moment acting on the rotor is determinable;
• a second sensor system configured to take measurements via which a thrust force acting on the rotor is determinable;
• a control device including a processor and a non-transitory computer readable medium having program code stored thereon;
• said program code being configured, when executed by said processor, to:
• provide first information which is representative for the tilt bending moment acting on the rotor;
• provide second information which is representative for the thrust force acting on the rotor;
• provide third information which is representative for a critical area of thrust forces and tilt bending moments;
• determine fourth information depending on the first information, the second information, and the third information which is representative for whether the tilt bending moment and the thrust force lie within the critical area;
• if the tilt bending moment and the thrust force lie within the critical area, generate an output signal configured to cause the pitch setting system to change the pitch angle of the at least one rotor blade in order to leave the critical area;
• said control device being signally connectable to said first sensor system and said second sensor system in order to provide said control device with the measurements of said first sensor system and said second sensor system;
• and,
• said control device being signally connectable to the pitch setting system in order to provide the pitch setting system with said output signal of said control device so that the pitch setting system sets the pitch angle of the at least one rotor blade depending on said output signal.

A wind turbine comprising:

• a rotor with at least one rotor blade;
• a tower;
• a pitch setting system for setting a pitch angle of the at least one rotor blade;
• and,
• a control system including a first sensor system configured to take measurements via which a tilt bending moment acting on said rotor is determinable;
• a second sensor system configured to take measurements via which a thrust force acting on said rotor is determinable;
• a control device including a processor and a non-transitory computer readable medium having program code stored thereon;
• said program code being configured, when executed by said processor, to:
• provide first information which is representative for the tilt bending moment acting on said rotor;
• provide second information which is representative for the thrust force acting on said rotor;
• provide third information which is representative for a critical area of thrust forces and tilt bending moments;
• determine fourth information depending on the first information, the second information, and the third information which is representative for whether the tilt bending moment and the thrust force lie within the critical area;
• if the tilt bending moment and the thrust force lie within the critical area, generate an output signal configured to cause said pitch setting system to change the pitch angle of said at least one rotor blade in order to leave the critical area;
• said control device being signally connectable to said first sensor system and said second sensor system in order to provide said control device with the measurements of said first sensor system and said second sensor system;
• and,
• said control device being signally connectable to said pitch setting system in order to provide said pitch setting system with said output signal of said control device so that said pitch setting system sets the pitch angle of said at least one rotor blade depending on said output signal.