Analysis of distribution transformer losses and life expectancy using measured harmonic data

Abstract

Three-phase distribution transformer in electrical power systems are usually designed for utilizing at the rated frequency and linear load. A different performance compared with that of the designed transformer occur when non-linear loads introduce harmonics to the supply. With the increasing use of nonlinear load the harmonic ay overheat the transformer leading to a poor power quality. The increased losses in the transformer due to the harmonic distortion can cause unnecessary winding loss and typical temperature rise. This paper presents the analysis and evaluation of distribution transformer losses under non-linear load by using real data. In this study, losses caused by harmonic and life of the distribution transformer were determined. Results show that an increase in the current harmonic distortion will increased in the current harmonic distortion will increase the transformer losses and hence decreased its life expectancy.