Reliable Estimation of Dissipation Factor of In-service Power Transformer

Insulation failure is a severe threat to high voltage equipment, and its protection using a reliable and efficient diagnostic tool has always been the interest to power utilities. Many traditional and newer techniques are available. Due to the complex aging process of oil-paper insulation, experts generally perform assessments after carefully evaluating measurement data. The paper presents a methodology to analyze recovery voltage measurement data to estimate aging sensitive performance parameters (dissipation factor).