A control device for damping electrical grid oscillations in a utility grid, where the control device comprises - an input for receiving a main damping reference signal determined for damping the grid oscillations, - a processor for determining at least first and second reference signals from the input for controlling power generation of first and second power generator units connected to the utility grid for delivering power to the utility grid, where - the first and second reference signals are determined so that the power delivered to the grid by the first and second power generator units in combination enables damping of the grid oscillations, and where - the first and second reference signals each comprise an active part for causing a control effect on the respective first and second power generator units and, successively to the active part, a passive part which does not cause a control effect, where the respective active parts of the first and second reference signals are separated in time - an output or distributor for transmitting or distributing the determined reference signals to power generator units, where - the main damping reference signal comprises first and second active parts (221, 222) in succession, where the first and second active parts (221, 222) are determined so as to counteract the grid oscillations given that the main damping reference signal was applied to the first or second power generating unit for controlling power generation, and where - the first and second reference signals are determined from the main damping reference signal so that the active part of the first reference signal is equivalent to the first active part of the main damping reference signal, and so that the active part of the second reference signal is equivalent to the second active part of the main damping reference signal. - an input for receiving a main damping reference signal determined for damping the grid oscillations, - a processor for determining at least first and second reference signals from the input for controlling power generation of first and second power generator units connected to the utility grid for delivering power to the utility grid, where - the first and second reference signals are determined so that the power delivered to the grid by the first and second power generator units in combination enables damping of the grid oscillations, and where - the first and second reference signals each comprise an active part for causing a control effect on the respective first and second power generator units and, successively to the active part, a passive part which does not cause a control effect, where the respective active parts of the first and second reference signals are separated in time - an output or distributor for transmitting or distributing the determined reference signals to power generator units, where - the main damping reference signal comprises first and second active parts (221, 222) in succession, where the first and second active parts (221, 222) are determined so as to counteract the grid oscillations given that the main damping reference signal was applied to the first or second power generating unit for controlling power generation, and where - the first and second reference signals are determined from the main damping reference signal so that the active part of the first reference signal is equivalent to the first active part of the main damping reference signal, and so that the active part of the second reference signal is equivalent to the second active part of the main damping reference signal.