Research on the dielectric properties and breakdown voltage of transformer oil-paper insulation after accelerating thermal ageing

摘要

In this paper, a set of accelerate thermal ageing experiments on oil immersed insulation paper were performed under 110❐ and lasted for more than 100 days. The degree of polymerization (DP), the frequency domain spectroscopy (FDS) and water concentration in insulating oil and paper, as well as the AC breakdown voltage of insulation paper were tested and analyzed. The results indicate that the dielectric properties can be used as indicators for the degradation evaluation of insulation paper. And the breakdown voltage of paper showed very little difference after accelerating thermal ageing, the electrical strength of oil-paper insulation system depends mainly on the performance of insulating oil.