Study and examination of transformer oil while exposed to air during operation

The immersed papers in transformers oil and the overall transformers oil tank that form the insulating materials are subjected to thermal and/or electrical fault from time to time which produce gases within the unit. The type of these gases can be classified according to the type of the fault and the generation gas rate can indicate the severity of the fault within the transformer, we can use these gases to diagnose it. During the normal investigation on a transformer inside one of electrical power station, it is found a problem in transformer oil, which is subjected to the atmospheric air during operation. Oxygen gas history of this transformer indicates that high oxygen gas levels dissolved in transformer oil within the interval between year 2003 and 2009. This paper deals as a case study a such transformer oil to discovered the new problem and further contribution when examination of transformer oil while exposed to air during operation. In this vein, the air leakage was discovered in 2009. In addition, oxidation of insulating paper and oil forms acids as the transformer ages, an increase in the acidity is a function of the rate of deterioration of the oil with Sludge. The acidity increased from 2004 to 2009 with rate approximately 6.9 times normal rate due to air leakage atmospheric contamination, moisture, oxygen, at normal operating temperature 80°C to 120°C where the insulating paper decomposition and deterioration forms furan compounds. Accelerate aging due to oxygen, moisture, and acidity, which reduce the lifetime of the transformer.