Experimental Investigations of FOV for Conventional and Hybrid Cylindrical Spacers in Compressed N2: SF6 Gas Mixture under AC Voltages

Abstract

Over the past two decades SF6 has been used as major insulation in compact GIS, GITL and GIC. In the past few decades SF6 has been used as insulating medium, however in recent years SF6 is identified as greenhouse effect gas which contribute to GWP. Hence attempts have been made to find suitable alternative to SF6 gas. The present study is undertaken using different N2:SF6 gas mixture ratio to determine the flashover characteristics under AC voltages. In this paper the effect of floating particles, use of different insulating spacers namely PMMA, PP and NYLON and their combination forms hybrid spacers has been studied in uniform electric field (Plane - Plane electrode) configuration. The surface flashover performances of individual and hybrid spacers have been compared in N2:SF6 gas mixture. The experimental analysis shows that hybrid spacers are more effective than individual spacers at low pressure.