Abstract—The oil/cellulose insulation system is one component of the transformer which, once subjected to normal and/or abnormal loading conditions cannot be replaced. Power factor and capacitance measurement are routinely used in the condition assessment of oil/paper insulated high voltage equipment. It is generally accepted belief that moisture in the oil/paper insulation increases the power factor and capacitance. This research is undertaken to study the insulation system of transformer and in-field measurement of power-factor and capacitance using the Doble M4000 insulation analyzer. The case studies on the different transformers showed how the trend of moisture and dielectric properties changes with the variation of power factor and capacitance of insulation system.

Index Terms—Insulation system; power transformer; power factor; capacitance.

Authors are with the Electrical Engineering Department of National Institute of Technology, Hamirpur, Himachal Pradesh, INDIA (mehtaamit5@gmail.com).

Cite: Amit Kumar Mehta, R. N. Sharma and Sushil Chauhan, "Condition Monitoring of Insulation System in Power Transformers," International Journal of Computer and Electrical Engineering vol. 4, no. 2, pp. 149-152, 2012.