Making prony analysis more accurate using multiple signals

Prony analysis has proven to be a valuable tool in estimating the modal con tent of power oscillations from measured ringdowns. The accuracy of the mod e estimates is limited by the noise content always found in field measured signals. current Prony analysis methods assume the system to be single outp ut, and individual signals are analyzed independently often resulting in co nflicting frequency and damping estimates (due to noise effects). This pape r considers a simple extension to Prony analysis that allows multiple signa ls to be analyzed simultaneously resulting in one set of mode estimates. Ex amples are used to show that this extension improves the accuracy of modal estimates and simplifies the analysis steps. The first example uses a Monte Carlo type simulation model and the second analyzes field measured data fr om the western North American power system.