METHOD FOR ATTENUATING LOW-FREQUENCY OSCILLATIONS IN AN ELECTRICAL POWER SUPPLY GRID

A method for attenuating low-frequency oscillations in an electrical power supply grid by means of a feed device which feeds into the electrical power supply grid, in particular a wind power installation, wherein the electrical power supply grid has a grid voltage and a grid frequency, comprising the following steps: picking up a grid signal having the low-frequency oscillations, splitting a total frequency range of the grid signal in which oscillations to be attenuated are to be expected into a plurality of partial frequency ranges, each having a lower and an upper range frequency, performing in each case one frequency analysis of the grid signal for each partial frequency range in order to identify in each case one or more oscillations having an oscillation frequency in the partial frequency range, if present, identifying a low-frequency oscillation to be attenuated as target oscillation depending on the frequency analyses of all of the partial frequency ranges, detecting the target oscillation at least according to frequency and amplitude and optionally according to phase, determining a setpoint attenuation signal depending on the target oscillation detected according to frequency and amplitude and possibly phase for attenuating the detected target oscillation, generating a setpoint feed signal depending on the setpoint attenuation signal and a basic setpoint signal, and generating and feeding in a feed signal depending on the setpoint feed signal (QE).