Method for operating a wind turbine

A device for performing open-loop and/or closed-loop control of a wind turbine at a location having an air density, comprising:

• an operational control system configured to:
• specify an air density at a location of the wind turbine, the wind turbine having an aerodynamic rotor with a plurality of rotor blades having a respective plurality of blade angles that are adjustable, and the wind turbine having a generator that is coupled to the aerodynamic rotor, and the rotor being capable of being operated with a rotor speed that is variable;
• retain a pitch characteristic curve;
• set a blade angle of a rotor blade of the plurality of rotor blades based on the pitch characteristic curve,
• the pitch characteristic curve specifying the blade angle as a function of air density at the location of the wind turbine and at least one of:
• an output power, torque and the rotor speed of the wind turbine,
• wherein according to the pitch characteristic curve, the blade angle, as a function of the air density, has a minimum in a region of a reference density at the location of the wind turbine.