The present invention concerns a method of controlling a wind power installation having a generator with a stator, a pole wheel with at least two rotor poles with a respective pole winding for producing a magnetic field guided in the respective rotor pole, and an air gap between the stator and the pole wheel, including the steps—controlling a respective exciter current through each pole winding,—varying at least one of the exciter currents relative to at least one further one of the exciter currents, and/or—varying at least one of the exciter currents in dependence on the position of the pole wheel in relation to the stator.