The primary objective of this study is to develop a condition assessment guide using DFR that considers characterizing service aged power transformers, based on estimating the moisture content of oil-immersed cellulose insulation as the most accurate test method.
The secondary objective of this study is to develop a guide to evaluate the influence of contamination, corrosive sulfide, carbonized paper, and oil conductivity on the DFR curves. This work focuses on literature reviews including standards (IEEE, CIGRE, IEC, etc.) to explore various approaches to develop a DFR based condition assessment guide for service aged power transformers. Utilities involved will be surveyed to incorporate best industry practices and latest trends. METSCO experience with DFR test will be used as a resource.