Negative Lightning Impulse Breakdown Characteristics of Mineral Oil with Different Nitrogen Addition Treatment Methods using Rogowski Electrodes

Abstract

We compared the lightning impulse (LI) breakdown voltages (BDVs) and/or breakdown characteristics of mineral oils treated by three different methods using Rogowski electrodes. These mineral oils had been treated to nitrogen gas filling, nitrogen bubbling addition, and nitrogen fine bubbles (FBs) addition respectively after degassing. As a result, it was found that there was almost no effect on LI BDVs by the difference of the nitrogen addition treatment methods. Additionally, there was almost no difference in the Formative time lag, the Statistical time lag and the distribution of discharge marks for each sample oil. Therefore, nitrogen FBs used in this study were not considered to be a factor in reducing BDV of mineral oil, similar to our previous report using spherical electrodes.