Study the harmonic characteristics of DC bias on the single phase power transformer

The dc bias effects on the magnetizing and magnetic induction are analyzed through their harmonic characteristics. A model transformer in order to analyzed the harmonic characteristic of the single phase power transformer under dc bias condition. The effect of dc bias will seen by the dc current injected on the winding of experiment system. Effect of that the linear value is changed with the ac excitation status. The characteristic of transformer excitation current resulting from DC offset current on the single phase power transformer. The dc bias can cause overheating, great noise, acute vibration, high temperature of transformer, effect of lower power quality and lot of harmonic will produce. The result of this study shows that the harmonic produce in the transformer and the even harmonics are significant in case of DC biased rather than in normal AC supply.