TRANSFORMER OIL TREATMENT

Oil in the transformer can be contaminated due to a number of factors such as; ageing, overheating, oxidation, faults in the transformer design, etc. Any one of these factors or combination will result in the built up of potentially harmful contaminants which could potentially destroy the transformer by shortening its useful operating life. If the transformer oil are diagnosed to have an unacceptable quantity of contaminants such as acids, sludge, moisture and dissolved gases, prompt treatment of the oil is required to prevent accelerating the deterioration of the transformer itself. Note that damage inflicted on a transformer cannot be reversed (unless it is stripped down and refurbished totally), but prompt and proper treatment of the contaminated oil can stop or at least slow down the deterioration process.

 

OIL TREATMENT METHODS AVAILABLE

Oil treatment options currently available are as follow

Filtration/Purification

Filtration will remove most free water (includes some dissolved water) and some trapped solid matter. It has major weaknesses. As the oil in the transformer is not treated chemically, it does not solve the sludge problem. More importantly, the process cannot remove dissolved oxidation by-products (like dissolved gases and acids) in the oil.

 

Transformer Oil Regeneration (TOR)

This basically involves three distinct processes; heating, absorption (reclamation) and vacuuming. The oil goes through the heating process which transforms the oil in the transformer into solvent for the sludge/oxidized by-products from the tank and solid insulation. Essentially, the heated oil dissolves such contaminants which otherwise the oil at normal temperature is unable to do so. The next process involves the removal of acids, sludges and other contaminants from the oil via the reclamation process. Finally, vacuuming removes moisture and gas in the oil.

 

Comparison between method of corrective oil work