Experimental Magnetization Curve of a Transformer Considering Harmonic Distortion

Abstract

Transformers are essential devices in power and distribution systems, since they reduce energy losses produced in the transmission stage. The magnetic system is the most-important part to its operation because energy conversion process will always be defined and bounded by the electromagnetic characteristics of its ferromagnetic core. This paper proposes an experimental method based on electromagnetic principles to obtain an approximated magnetization curve of an electric transformer, which can be used as a reference to analyze magnetic-system-behavior evolution through time. Moreover, the obtained magnetization curve considers voltage and current harmonic components produced during the test. Therefore, a detailed division of input transformer power is done, assuming the total active power are magnetic losses and the total non-active power corresponds to magnetization power. Obtained results showed the proposed method relevance, after comparing it with a magnetization curve which rejects harmonic content of signals and a magnetization curve released by a ferromagnetic material manufacturer.