Aging Degradation of Insulation Paper in Power Transformers by XRD Method

摘要

The aging degradation of paper insulation in transformers is usually evaluated by the dissolved products in oil, such as CO/CO₂, furfural and methanol. However, these methods are difficult to explain the internal aging mechanism of paper insulation. In this paper, in the condition of simulated accelerated aging, the surface morphology and cellulose crystallinity were studied to explore the degradation mechanism of insulation paper under different aging time, which provided theoretical basis and precaution for the aging of insulation paper. The results showed that surface morphology of paper had no obvious changes in the early aging stage, but cracks and holes appeared on the surface in the severe aging stage. The relative crystallinity of insulation paper increased with the aging time, meaning that thermal aging changed the internal structure of cellulose. The reason was speculated to be that more hydrogen bonds were formed between the multiple small cellulose chains after the main cellulose chain break, which increased the crystallinity of the paper insulation.