Effects of voltage harmonics on distribution transformer losses

The effect of harmonic contamination on distribution transformer losses has become an increasing concern over the last decade. This problem is caused by the widespread presence of non-linear loads and their ever-increasing proportion in the power system networks. In this paper, an oil-filled distribution transformer was employed to run short circuit test and open circuit test. The electrical parameters of transformer were obtained and the effect of harmonics on these parameters was discussed. Also, the two-frequency method was applied to separate the no-load hysteresis loss and no-load eddy current loss.