The extended frequency-directed EMD technique for analyzing the low-frequency oscillations in power systems

As distinct from the various simulation results, both computational and physical, actual low-frequency oscillations in power systems are nonlinear and non-stationary processes. Thus, the selection of the methods to be used for the purpose of the oscillations analysis is limited. The Empirical Mode Decomposition technique has been widely applied in many fields during previous years in spite of numerous known challenges associated with its application. Many researchers proposed the technique modifications to suit it to their particular problems and needs. Since the Empirical Mode Decomposition relies on an adaptive basis, it corresponds to the properties of the low-frequency oscillations in power systems - nonlinearity and non-stationarity. Various modifications of the technique have been analyzed in terms of provided quality and speed of operation. Based on the results, the novel Extended Frequency-Directed modification is proposed for the purpose of analyzing the low-frequency oscillations in power systems.