Impacts of Non-Sinusoidal Load Currents on Distribution Transformer Losses-Part II: Standard Aspects and Experimental Measurement

Nowadays, reliability is an inevitable part of power system studies and operation, due to significant increase in the number of industrial electrical consumers. Transformer is one of the major and critical components in power system and distribution network in the area of reliability issue, since their outage may result in costly and time-consuming repair or replacement. Nowadays, loads of transformers are widely perturbed with harmonics. Harmonic components cause the transformer losses to increase and thus, transformer may fail to operate. In this paper, as a Part II of our study, effects of non-sinusoidal load currents on distribution transformer losses have been studied by means of IEEE standard and experimental measurement. For this purpose, the losses of a typical distribution transformer under non-sinusoidal loads have been measured. Afterwards, by considering harmonic spectrum of the used non-linear loads, transformer losses have been calculated using IEEE C 57.110 standard. Finally, obtained results have been compared. It should be mentioned that in Part I of this study, distribution transformer losses under non-sinusoidal load currents have been evaluated and calculated using Finite Element Method and a circuit based method by means of a transient software. Copyright (C) 2011 Praise Worthy Prize S.r.l. - All rights reserved.