Study of Frequency Domain Spectroscopy on model transformer windings at elevated temperatures

This paper discusses the results of Frequency Domain Spectroscopy of paper-oil insulation of model transformers at higher temperatures. The variations in tan δ and real and imaginary part of complex permittivity with respect to copper sulphide contamination of paper oil insulation of laboratory model windings at higher temperatures are presented and analyzed. Results show that there is a significant increase in tan δ and complex permittivity at higher temperatures.