Power Transformer Protection

Abstract—A power transformer is a very valuable and an important link in power transmission system. It provides voltage transformation and power transfer. Faults occur in transformer due to insulation breakdown, aging of insulation, overheating due to over-excitation, oil contamination and reduced cooling. It is an important aspect to implement reliable, secure and fast protection scheme which is essential to minimize damage. In this paper, various faults taking place in transformer and suitable protections are described. This paper will be useful to enhance knowledge of the students and practicing engineers in the area of substation engineering. Keywords—Differential protection, back-up protection, over fluxing, Buchholz relay I