A comprehensive diagnostic evaluation of power transformers via dissolved gas analysis

Abstract

This paper describes a relatively new method for understanding the relationship of the carbon oxide gases in transformer main tanks, which is currently not well known in the industry. This new diagnostic method is not only educational, but simple to understand and will assist the technician/engineer in determining whether a problem can most likely be repaired on site, or not. In this paper a comprehensive, simplified method for determining the location of developing problems within a power transformer will be provided, which includes overheating leads, core, main winding paper, de-energized tap changers (DETC). Since online tap changers (OLTC) play a vital role in the performance of the transformer, DGA diagnostics are included in this paper.