Furfural Analysis on Aging State Assessment of Oil-Immersed Transformers: A Review

Furfural analysis is widely used in the aging state assessment of oil-immersed transformers due to its close relationship with the degradation of insulation paper. Herein, we present a critical overview of important insights and progress on furfural analysis, including production mechanism, measurement progress, production amount, stability, and distribution law of furfural in oil-paper systems. The relationship between the furfural content in oil and the polymerization degree (DP) of insulation paper is also analyzed. Considering the engineering application of furfural analysis for field transformers, the authors’ viewpoints regarding present problems and challenges are further discussed, and prospective development directions for furfural analysis are proposed for future research.