Investigating the Positive Lightning Impulse Breakdown Voltage and Acceleration Voltage of Selected GTL Based Dielectric Liquids

This paper presents a comparison of the lightning properties of three insulating fluids. Conventional inhibited mineral oil (IMO) was compared with two inhibited liquids made using Gas-to-Liquids technology (GTL), which were marked as GTL-I and GTL-I-GA. The focus was on two parameters: lightning impulse breakdown voltage (LIBV) and acceleration voltage $\left(\mathrm{V}_{\mathrm{a}}\right)$. Tests were performed in the condition of highly non-uniform electric field distribution represented by 25 mm and 40 mm point-sphere gap. The highest value of LIBV was recorded for inhibited liquid made using GTL technology (GTL-I). However, the highest acceleration voltage was achieved by inhibited gas-absorbing GTL fluid (GTL-I-GA).