Furan Analysis on Transformer Oil

One of the primary inputs of a transformer is its insulation material and majorly used insulation materials includes transformer oil, insulating paper and press board. These insulators are required to undergo tests from time to time to ensure proper functioning of transformers. The life of paper insulation can be determined by its degree of polymerization and its tensile strength. However for transformers which are functioning, testing them using paper samples becomes unfeasible. Alternative method for evaluating paper insulators is through an aromatic compound called furan, which is released into the transformer oil as paper insulation experiences degradation.

The life of paper insulation typically depicts the life the transformer, as long as the condition of paper insulation is in place the transformer can function effectively. Paper insulation is made up of cellulose fibres which is a polymer formed from glucose. As the transformer operates polymer chains breaks down and becomes shorter. Reduced degree of polymerization cause the tensile strength of the paper to fall short. This implies when polymerization reduces any stress or minute strain would result in faults and failure within the transformer. Split in polymer chains causes release of chemical compounds like carbon monoxide, carbon dioxide and water. Glucose molecules also undergo changes during this split and all this result in formation of furan rings.

Furan is a heterocyclic compound which has five major derivatives which are- 2-furaldehyde, furfuryl alcohol, 2=acetylfuran, 5-methyl-2-furaldehyde and 5-hydroxmethyl-2-furaldehyde. To determine the degree of polymerization the furan compound is extracted through sample of transformer oil. This oil is extracted with help of a liquid acetonitrile or with solid phase extraction. The five compounds are separated through ultraviolet detectors with appropriate wavelengths. The furans in the oil are then analysed with help of high performance liquid chromatographers.

Along with dissolved gases analysis, furan analysis is regarded as one of the vital non intrusive tests undertaken to monitor the functioning of transformers. The condition of cellulose based insulation can be detected through furan analysis which normally goes undetected in dissolved gas tests, which indicates its significance. Furan analysis is done once every two years to estimate the remaining life of a transformer.

Author-  is an eminent and experienced Content Writer in Transformer Oil related topics. Author has  written several articles on Furan Analysis Of Transformer Oil and Fuel Oil Analysis  in India.