This paper presents the results of the experimental studies on lightning impulse breakdown tests of two categories of vegetable oil – saturated versus unsaturated. The saturated vegetable oils comprise refined, bleached, and deodorized coconut oil and virgin coconut oil (i.e., RBDCO and VCO), while the unsaturated vegetable oil is the most commonly used soybean oil called ‘MIDEL eN1215′. The differences in the impulse breakdown performance of the two categories of vegetable oil were analyzed from the perspective of molecular ionization and ionization potential. The effect of the residual mineral oil on impulse breakdown performance was also studied and analyzed. A point-sphere electrode system was used in this study. It is observed that at a 12.5 mm gap, the lightning impulse breakdown voltage (LIBDV) of both RBDCO and VCO were nearly similar to natural ester oil (NEO) subjected to positive excitation, but with negative excitation, the latter appears to be inferior. At twice the electrode gap, LIBDV can easily differentiate between unsaturated and saturated vegetable oils, whatever be the polarity of excitation. With mineral oil, up to 20%, LIBDVs of vegetable oil tend to increase. This is mainly important with positive excitation, especially in NEO, where up to a 25% increase was observed as against pure oil.

本文介绍了对两类植物油（饱和与不饱和）的雷电冲击击穿试验的实验研究结果。饱和植物油包括精制、漂白和除臭椰子油和初榨椰子油（即 RBDCO 和 VCO），而不饱和植物油是最常用的称为“MIDEL eN1215”的大豆油。从分子电离和电离势的角度分析了两类植物油脉冲击穿性能的差异。还研究和分析了残余矿物油对脉冲击穿性能的影响。本研究使用点球电极系统。可以观察到，在 12.5 mm 的间隙处，RBDCO 和 VCO 的雷电冲击击穿电压 (LIBDV) 与受到正激励的天然酯油 (NEO) 几乎相似，但在负激励下，后者似乎较差。在两倍的电极间隙处，LIBDV 可以轻松区分不饱和植物油和饱和植物油，无论激发极性如何。矿物油含量高达 20% 时，植物油的 LIBDV 往往会增加。这对于正激发很重要，特别是在 NEO 中，与纯油相比，观察到的增加高达 25%。高达 20%，植物油的 LIBDVs 往往会增加。这对于正激发很重要，特别是在 NEO 中，与纯油相比，观察到的增加高达 25%。高达 20%，植物油的 LIBDVs 往往会增加。这对于正激发很重要，特别是在 NEO 中，与纯油相比，观察到的增加高达 25%。