Effects of harmonics on distribution transformers

Proliferation of harmonics in power distribution systems, which are using increased nonlinear loads, have become a power quality problem for both customers and suppliers. The harmonic power losses not only cause an increase in operational costs but also create additional heating in power system components, which in turn will reduce their life expectancy. This happens especially in commercial buildings, where usage of nonlinear loads is very high. In general the cost of power quality and in particular the aging costs due to harmonic losses in transformers will increase since harmonics will affect all power system equipment. This study examines the effect of harmonic distortion on power transformers when supplying nonsinusoidal load currents. The Malaysian standards are used in the findings for comparison. For this research, the harmonic problem can be analysed with simulations, real measurements and assessments. The results show that an increase in the current harmonic distortion can increase transformer losses and decrease its life expectancy.