A method for controlling the operation of a wind turbine which includes a mechanical drive train, an electric generator being mechanically connected to the drive train, and a power converter being electrically connected to the generator is provided. The method comprises (a) determining a frequency of an AC output voltage signal provided by the power converter; (b) recognizing, whether there has been a modification of the determined frequency with respect to a previously determined frequency, which modification is larger than a given threshold; (c) if the modification of the determined frequency is larger than the given threshold, changing a power reference signal for the wind turbine; (d) providing the changed power reference signal to a controller of the wind turbine; and (e) controlling the operation of the wind turbine on the basis of the changed power reference signal.