At present, the paper insulation material for domestic power transformers is mainly made of wood pulp, with cellulose as the main component. When the insulation paper deteriorates, cellulose degrades to produce a portion of D-glucose monomers, which are easily decomposed under the operating conditions of the transformer. Finally, a series of oxygen heterocyclic compounds dissolved in the transformer oil are produced, and furfural is a major oxygen heterocyclic compound formed after the degradation of cellulose macromolecules.

Qualified new transformer oil does not contain furfural, and the aging of non cellulose insulation materials inside the transformer does not produce furfural. The furfural in transformer oil is a product only generated by the aging of paper insulation. Therefore, testing the furfural content in oil can reflect the aging condition of transformer paper insulation.Tianzhao Company has explored and optimized the experimental conditions based on relevant standards and literature in the power industry, and proposed a solution for detecting furfural in transformer oil.