Maintenance of transformer oil is vital and that the life of the transformer can be extended up to 50 years if maintained properly.
There is a misconception that transformers do not require maintenance after installation, this, however, is not the case. Regular oil analysis is necessary to determine the condition of the oil and, thus, the treatment required.
So What happens to transformer oil and why it requires regular monitoring.
Insulation oil at the right level of refinement has less solubility for water. When oil oxidises it produces water, acids, sludge and other polar compounds as degradation products. The cellulose insulation of the transformer acts as a ‘filter’, attracting the decay products through adsorption. Once sludge is absorbed into the cellulose, the degree of polymerisation and tensile strength starts to decline and the cellulose insulation begins to lose its pliant quality.
If this ‘filter’ is not cleaned, it will eventually be destroyed by the decay products. Our company maintains that the best and most cost-effective method for cleaning the ‘filter’ is through hot oil treatment, which is on-site on-line regeneration of oil in the transformer tank.
Regeneration and desludging effect a great change in transformer oil. The regeneration process incorporates purification as part of the regeneration process. While transformer oil meets the requirements in just one cycle through the regeneration plant, more cycles are required to clean the inside of the transformer and remove contaminants adsorbed by the cellulose insulation.