Removal of nuisance signals in electric grid disturbance data

An iterative algorithm for filtering out nuisance signals in recorded fault and disturbance data is presented. The intended application of the algorithm is removal of transient signal components (due to instrument transformers and network transient processes) as well as interharmonics in short-duration digital records of voltage and current signals. Output of the algorithm is a system frequency dynamic phasor which can be used in the automated disturbance data analysis in power systems. Commonly used, the Fourier transform based signal processing algorithms are not able to efficiently filter such components. Due to short lengths of recorded signals, frequency resolution of the Fourier transform based algorithms is not sufficient for this application. To demonstrate practicality and accuracy of the proposed algorithm several simulation experiments are devised and results are presented in the paper.