A method for controlling a wind farm for damping low-frequency electrical oscillations, in particular subsynchronous resonances, in an electrical supply grid, wherein the supply grid has a line voltage with a nominal line frequency and an operating point which is characterized by load flows, wherein the wind farm has at least one wind power installation (100, 300) connected to the electrical supply grid, comprising the steps: - detecting at least one low-frequency electrical oscillation of the electrical supply grid, - determining in each case an oscillation characteristic of the at least one detected oscillation, wherein the oscillation characteristic describes at least one property of the detected oscillation, and determining an oscillation characteristic includes determining an oscillation mode; - specifying an active power damping signal (ΔP) and/or a reactive power damping signal (ΔQ) in each case for damping the at least one low-frequency oscillation characterized by the oscillation characteristic; - feeding an active power component in accordance with the active power damping signal or a reactive power component in accordance with the reactive power damping signal, wherein feeding the active power component and/or the reactive power component into the electrical supply grid takes place in such a way that load flows in the supply grid are changed in order to change the operating point of the electrical supply grid, and wherein - specifying the active power damping signal (ΔP) or the reactive power damping signal (ΔQ) takes place depending on the determined oscillation characteristic, and - the respective oscillation mode of the detected low-frequency oscillation in the electrical grid is taken into account in order to carry out a feed-in which is adapted to this, wherein - a damping of low-frequency oscillations is influenced differently via the active or reactive power feed-in depending on the oscillation mode. - detecting at least one low-frequency electrical oscillation of the electrical supply grid, - determining in each case an oscillation characteristic of the at least one detected oscillation, wherein the oscillation characteristic describes at least one property of the detected oscillation, and determining an oscillation characteristic includes determining an oscillation mode; - specifying an active power damping signal (ΔP) and/or a reactive power damping signal (ΔQ) in each case for damping the at least one low-frequency oscillation characterized by the oscillation characteristic; - feeding an active power component in accordance with the active power damping signal or a reactive power component in accordance with the reactive power damping signal, wherein feeding the active power component and/or the reactive power component into the electrical supply grid takes place in such a way that load flows in the supply grid are changed in order to change the operating point of the electrical supply grid, and wherein - specifying the active power damping signal (ΔP) or the reactive power damping signal (ΔQ) takes place depending on the determined oscillation characteristic, and - the respective oscillation mode of the detected low-frequency oscillation in the electrical grid is taken into account in order to carry out a feed-in which is adapted to this, wherein - a damping of low-frequency oscillations is influenced differently via the active or reactive power feed-in depending on the oscillation mode. - specifying the active power damping signal (ΔP) or the reactive power damping signal (ΔQ) takes place depending on the determined oscillation characteristic, and - the respective oscillation mode of the detected low-frequency oscillation in the electrical grid is taken into account in order to carry out a feed-in which is adapted to this, wherein - a damping of low-frequency oscillations is influenced differently via the active or reactive power feed-in depending on the oscillation mode.