Back to the basics — Event analysis using symmetrical components

Abstract

This paper highlights the use of symmetrical components for simplifying the analysis of events with uncommonly seen fault waveforms. The paper goes back to the roots and gives a brief refresher on symmetrical component theory. Then, three real-world events involving transformers are presented along with the relay event oscillography. A hypothesis is developed for each event to explain the waveforms, and then corresponding sequence networks are solved for phase currents to verify the hypothesis.