Electrical Breakdown Characteristics of N2Gas under Impulse Voltages

This paper aims to examine the possibility of using an environmentally friendly N₂ as an alternative gas to SF?. For this purpose, we have investigated breakdown characteristics of N₂ under impulse voltages in a quasi-uniform electric field gap. The 1.2/50[㎲] lightning impulse voltage, switching impulse voltages and oscillatory impulse voltages were applied at the test gap. The electric field utilization factor ranges from 0.5 to 0.8. The experimental data of SF6 and N₂ acquired in the same experimental condition are presented in parallel for comparison. As a result, the breakdown voltages in SF? and N₂ are linearly increased with the gas pressure, also the breakdown voltages in N₂ are increased with increasing the gap distance and electric field utilization factor. The positive breakdown voltages are higher than the negative breakdown voltages. The nagative basic lightning impulse withstand level of 150[㎸] in N₂ of about 0.5[㎫] is nearly equal to that in SF? of 0.15[㎫]. It is seen from the results obtained in this work that N₂ can be used as an eco-friendly alternative gas to SF? in distribution power equipment.