A method for controlling load reduction for a wind turbine rotor with rotor blades comprising an aerodynamic active element responsive to a control signal for modifying its setting is provided. The loads acting on the rotor blades in relation to the rotor's azimuth are detected and individual control signals based on a PI control system are established. Each individual control signal is a complex number containing an amplitude defining the degree of modification of the respective setting and an angle defining the phase of the modification of the respective setting with respect to the rotor's azimuth. The angle of the complex number is corrected by a phase correction factor. The elements are provided with the individual control signals. The input to the PI-control system is a complex load vector.