窒素付加処理方法が異なる鉱油の交流および負極性雷インパルス絶縁破壊電圧

抄録

We investigated and compared the alternate current (AC) and lightning impulse (LI) breakdown voltages (BDVs) of mineral oils that 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 AC and LI BDVs by the difference of the nitrogen addition treatment methods. Additionally, the LI ratio of mineral oils were found to be approximately 2.41 to 2.68. Furthermore, nitrogen FB equal or less than 2 µm in diameter was not considered to be a factor in reducing BDV and breakdown electric field (BDE) of mineral oil.