Method of damping electromechanical oscillations on a power system by injecting reactive power generated by one or more wind energy turbines (WTG 1-5), wherein a reactive power controller is adapted to determine a reference reactive power value (Q ref) depending on an actual system voltage (U meas), the method comprising: - measuring oscillation data associated with the power system, - filtering (84, 71) the measured oscillation data to remove a steady state offset, thereby obtaining filtered oscillation data, - determining a frequency value and an amplitude value from the filtered oscillation data, and - triggering a switchable power oscillation damping according to at least one criteria of the following: o the frequency value determined from the filtered oscillation data falling within a predetermined frequency interval, and o the amplitude value determined from the filtered oscillation data exceeding a predetermined threshold value, - wherein the switchable power oscillation damping is achieved by compensating a gain and a delay caused by the reactive power controller to the reference reactive power value (Q ref), thereby obtaining a corrected reference reactive power value - wherein, additionally to the above switchable power oscillation damping, a continuous power oscillation damping is provided, which comprises the steps of correcting a gain and a shift in either the corrected reference reactive power value in case the switchable power oscillation damping is triggered, or in the reference reactive power value (Q ref) in case the switchable power oscillation damping is not triggered, thereby compensating a gain and a delay caused by the reactive power controller, - outputting a reactive power setpoint (O set,WTGs) to at least one of the plurality of wind energy turbines (WTG 1-5) based on at least one of: the reference reactive power value (Q ref) and the corrected reference reactive power value. - measuring oscillation data associated with the power system, - filtering (84, 71) the measured oscillation data to remove a steady state offset, thereby obtaining filtered oscillation data, - determining a frequency value and an amplitude value from the filtered oscillation data, and - triggering a switchable power oscillation damping according to at least one criteria of the following: o the frequency value determined from the filtered oscillation data falling within a predetermined frequency interval, and o the amplitude value determined from the filtered oscillation data exceeding a predetermined threshold value, o the frequency value determined from the filtered oscillation data falling within a predetermined frequency interval, and o the amplitude value determined from the filtered oscillation data exceeding a predetermined threshold value, - wherein the switchable power oscillation damping is achieved by compensating a gain and a delay caused by the reactive power controller to the reference reactive power value (Q ref), thereby obtaining a corrected reference reactive power value - wherein, additionally to the above switchable power oscillation damping, a continuous power oscillation damping is provided, which comprises the steps of correcting a gain and a shift in either the corrected reference reactive power value in case the switchable power oscillation damping is triggered, or in the reference reactive power value (Q ref) in case the switchable power oscillation damping is not triggered, thereby compensating a gain and a delay caused by the reactive power controller, - outputting a reactive power setpoint (O set,WTGs) to at least one of the plurality of wind energy turbines (WTG 1-5) based on at least one of: the reference reactive power value (Q ref) and the corrected reference reactive power value.