Statistical analysis of empirical magnitude and phase response estimates with applications to power system identification

This paper discusses the analysis of power system probing data with a nonparametric system identification method called Empirical Transfer Function Estimate (ETFE). ETFE is the ratio of the Discrete Fourier Transforms (DFT) of the output and the input signals. Expressions for statistical moments of the magnitude and phase response estimates for ETFE are derived and estimated. A simple method for estimation of noise spectrum is also discussed. The paper discusses the application of these results to low level probing tests of the western North American power system (wNAPS). The results from simulation data and measured PMU data are reported.