Difference of Discharge Phenomena under GFRP and CFRP Insulation Barrier with Steep Impulse Voltage

Abstract

Recently, many researchers focus on glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP) materials because these materials have superior mechanical properties. Therefore, their electrical insulation performance must be revealed. Especially, the discharge which occurred under insulation barriers has not been revealed. So, we have investigated the discharge phenomena under GFRP and CFRP insulation barriers. In this study, we used a needle-plane short air gap in the discharge chamber. The insulation barrier was placed 2 mm below the brass needle electrode and 5 mm above the plane electrode. Synthetic air (N2 (79%)/O2 (21%)) or room air was injected into the chamber at atmospheric pressure. The steep impulse voltages were repeatedly applied to the needle electrode. As a result, the surface discharge (SD), it developed in both gases on GFRP insulation barrier. However, it didn't develop on CFRP insulation barrier. Regarding the discharges under GFRP insulation barrier (barrier-plane discharges: BPDS), they mainly appeared in its center area at synthetic air. On the other hand, the discharges under CFRP insulation barrier appeared in overall area at both gases. In addition, the discharges were not occurred with the standard lightning impulse voltage.