Condition Assessment of Oil-Paper Transformer Insulating System

Damages of power transformers are caused partly by construction setting but also by operation （i. e., due to operational and degradation parameters）. A long-term operation and exceeding of the limit values of transformer abbreviate the lifetime of this device very dramatically. A condition of insulating system oilpaper is principal diagnostic indicator that has its essential influence to failure-free operation of power transformers. The paper deals with a description of the experience with developed monitoring system, which is focused mainly on a control of oil filling of experimental transformer. Relative humidity, amount of dissolved gases and increased temperature are observed, as they have decisive influence on insulating system of transformer. Monitoring of these characteristics is completed with analysis of oil samples by infrared spectroscopy in mode of Attenuated Total Reflection technique.