Lightning Impulse Breakdown Improvement Properties of Cellulose Insulation Pressboard Impregnated With Three-Element Mixed Insulation Oil

Here, the lightning impulse breakdown characteristics of mineral oil-impregnated paper (MO-P) (pressboard) and three-element mixed insulation oil (TEMO)-impregnated paper were tested. Molecular simulation was used to analyze the difference in lightning impulse breakdown characteristics of the two oil-impregnated papers at the atomic scale. The results show that when the thickness of the insulation paper layers is 0.1 and 0.5 mm, the lightning impulse breakdown voltage of TEMO-paper (TEMO-P) is slightly lower than that of MO-P; however, when the insulation paper layer thicknesses are 1 and 1.5 mm, the lightning impulse breakdown voltage of TEMO-P is greater than that of MO-P. Additionally, the breakdown time of TEMO-P is longer than that of MO-P, regardless of positive or negative polarity. The discharge process of different oil-impregnated papers depends on the discharge characteristics of the insulating oil and the insulating paper itself and the matching characteristics of the insulating paper and the insulating paper. This report provides theoretical guidance for an in-depth exploration of the differences in the lightning impulse breakdown characteristics of different oil-impregnated papers.