Transformer Saturation Effects on EHV System Overvoltages

Transformer saturation affects system over-voltages caused by transformer energization, fault application and clearing, and load rejection. Only some of these effects are desirable. The paper presents an analysis of such effects supported by results obtained on a typical long EHV transmission system by means of a power system simulator. An analysis of harmonic currents generated by a saturated transformer is also presented as a contribution to a better understanding of the phenomena considered.