A method performed by one or more devices is disclosed in which network topology information indicative of a function of a power network is gathered at a predetermined nominal frequency. The nominal frequency is influenced by a power input, a power output, a rotational speed, a torque, a modulation angle, and/or a phase angle of components included in the power network. Harmonic information indicative of one or more harmonic levels is determined from the components of the power network or from one or more network nodes. The harmonic information is determined based on the network topology information. Evaluation information indicative of an occurrence of one or more resonances and/or harmonic level increases in the power network is determined. The evaluation information is determined based on the determined harmonic information. The determined evaluation information is output.