A modified dielectric dissipation factor measurement technique for transformer insulating oil

This paper proposes a low cost mechanism to accurately measure the dissipation factor and its allied effect over transformer insulating oil. The measuring circuit is a modified De Sauty bridge network where the accurate parameter measurement can been performed. The effect of stray capacitance over dielectric loss and dissipation factor has been nullified by the application of operational amplifier in the circuit. Different samples of transformer insulating oil have been tested based on their aging and moisture content to check the reliability of the proposed measuring technique. Experimental result shows the efficacy of the proposed method when compared to existing IEC and ASTM standard procedures and commercial measuring devices. Measurement error analysis with repeatability and uncertainty calculation shows promising result and is within the acceptable limits.