An investigative study of the application of fundamental operations of mathematical morphology in the diagnosis of oscillatory transients

Abstract

The Oscillatory Transient (OT) has defined characteristics such as a small duration, considerable variations in the voltage and frequency amplitude and can manifest itself in any part of an Electric Power System (EPS). The switching of Capacitor Banks (CBs) mainly causes the OT. The complete methodology to analyse this kind of disturbance should contemplate the study of detection of the beginning of an OT until the extraction of the main characteristics of the analyzed signal. In this research, Mathematical Morphology (MM) is applied to identify the beginning of an OT, focusing on the expansion, opening, and Dilation-Erosion Difference Filter (DEDF) filter operations. In the sequence, a matching search (MPA–Matching Pursuit Algorithm) was applied to extract parameters from a structured data dictionary. Among the results, the application of DEDF stands out, which better identifies the beginning of OT, allowing the parameters of frequency (f), damping (λ) and angle of phase (ϕ) extracted to represent and characterize the analyzed signals.