Oil reclaiming - one sustainable way to extend the lifetime of power transformers

High concentration of degradation products in the insulating liquid (commonly called transformer oil) can be harmful to transformer's performance. Therefore, it is necessary to maintain the oil in good condition during the transformer's operating lifetime. An environmentally friendly approach to maintain the transformer oil in good conditions isOil reclaiming.Oil reclaiming is a technology that eliminates or reduces soluble and insoluble polar contaminants from the oil by chemical and physical processing. Improvements in the physicochemical properties of the oil after reclaiming are visible and measurable. Nevertheless, there is a lack of information on the medium-and long-term impacts of oil reclaiming on the rate of oil degradation. In this paper we studied dozens of transformer oils before and after reclaiming, some of which were reclaimed more than ten years ago. From our results we can conclude that after reclaiming, oils exhibited a lower rate of degradation, in addition to the environmentally friendly character of the oil reclaiming process as an alternative method to extend the oil lifetime. We therefore conclude that oil reclaiming resulted in an extension of the transformer's lifetime beyond what was foreseen with the initial oil.