Abstract: The present invention relates to a method of monitoring oscillations that are liable to interact in an electrical power network, in dependence on measurement of AC waveforms in the electrical power network. The method comprises receiving first waveform data corresponding to an electrical quantity in each phase of at least two phases of three-phase AC waveforms at a location in the electrical power network. The method further comprises applying a transformation to the first waveform data to provide therefrom second waveform data corresponding to an electrical quantity at the location in a single phase representation, the second waveform data depending on the at least two phases.

Abstract: The present invention relates to apparatus (10) for determining a contribution of at least one grid subsystem of plural grid subsystems to oscillation in angle or grid oscillation in an electrical grid (12). The apparatus (10) is configured to receive a first quantity which corresponds to oscillation in angle at a first grid subsystem (14). The apparatus (10) is also configured to receive a second quantity which corresponds to oscillation in angle at a second grid subsystem (16). The apparatus (10) comprises a processor (32) which is operative to determine a contribution of at least one of the first and second grid subsystems to oscillation in angle or grid oscillation with the contribution being determined in dependence on a phase relationship between the first and second quantities.

Abstract: The present invention relates to a method of monitoring oscillations that are liable to interact in an electrical power network, in dependence on measurement of AC waveforms in the electrical power network. The method comprises receiving first waveform data corresponding to an electrical quantity in each phase of at least two phases of three-phase AC waveforms at a location in the electrical power network. The method further comprises applying a transformation to the first waveform data to provide therefrom second waveform data corresponding to an electrical quantity at the location in a single phase representation, the second waveform data depending on the at least two phases.

Abstract: The present invention relates to apparatus (10) for determining a contribution of at least one grid subsystem of plural grid subsystems to oscillation in angle or grid oscillation in an electrical grid (12). The apparatus (10) is configured to receive a first quantity which corresponds to oscillation in angle at a first grid subsystem (14). The apparatus (10) is also configured to receive a second quantity which corresponds to oscillation in angle at a second grid subsystem (16). The apparatus (10) comprises a processor (32) which is operative to determine a contribution of at least one of the first and second grid subsystems to oscillation in angle or grid oscillation with the contribution being determined in dependence on a phase relationship between the first and second quantities.