American Journal of Engineering and Applied Sciences

Aging Study and Lifetime Estimation of Transformer Mineral Oil

Mohammad R. Meshkatoddini

DOI : 10.3844/ajeassp.2008.384.388

American Journal of Engineering and Applied Sciences

Volume 1, Issue 4

Pages 384-388

Abstract

Problem statement: Power transformer is the most expensive equipment in electrical network; and the mineral oil has the main roles of insulating and cooling in it. Oil is subjected to the degradation because of the ageing, high temperature and chemical reactions such as the oxidation. Then the oil condition has to be checked regularly and reclaimed or replaced when necessary, to avoid the sudden failure of the transformer. It will be very desirable also if we can predict the transformer oil remaining lifetime, from time to time. Approach: An experimental study was accomplished on the used oil specimens coming from several power transformers of various ages, working in Iranian power network, to recognize the correlation between the real age of the oil and the rate of its different characteristics and to know the most appropriate property which can represent its ageing. Accelerated aging experiments were accomplished on oil specimens at different temperatures. Furthermore a method for estimation of the remaining lifetime of the oil, using Arrhenius law, was employed. Results: According to our experiments, it was verified that, by using Celsius degrees and natural logarithm, the Arrhenius law can be applied properly to the thermal degradation phenomena of the oil. Conclusion: It was shown that the presented method can be used to study the degradation of transformer mineral oil and to estimate its remaining lifetime.

Copyright

© 2008 Mohammad R. Meshkatoddini. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.