Estimation of power-system damping from synchrophasor frequency measurements is studied. Specifically, a procedure for determining the damping of a dominant mode from the turns ratio of the sample autocorrelation function is outlined. The main contribution of the work is to then develop performance bounds on the damping estimates, and demonstrate approximation of these bounds entirely from the measurement data. The technique has been applied to archived historical data from the Western Electricity Coordinating Council (WECC), and a real-time implementation has also been developed.

1 aRoy, Sandip1 aLesieutre, Bernard uhttps://certs.lbl.gov/publications/sample-autocorrelation-based-approach01218nas a2200121 4500008004100000245007700041210006900118260003400187520075800221100002600979700001601005856007501021 2017 eng d00aA system response persistence measure for use in ambient data monitoring0 asystem response persistence measure for use in ambient data moni aMorgantown, WVbIEEEc09/20173 aTo aid in the real-time monitoring of system stability, it is useful to assess the relative damping of an underlying impulse response from noisy, ambient data. This is typically done using modal decomposition, procedures that accurately and consistently estimate natural frequencies of oscillation but struggle with estimates of damping. Here we introduce a measure of “persistence” as a robust measure of the duration of an impulse response. The longer a natural response persists the less damping it is perceived to have. The proposed measure scales linearly with the duration of an impulse response. It is easy to calculate as the energy in a normalized autocorrelation signal, and it serves as a measure of (inverse) damping.

1 aLesieutre, Bernard, C1 aRoy, Sandip uhttps://certs.lbl.gov/publications/system-response-persistence-measure