Dielectric Strength of C5 Perfluoroketone

Sulfur-Hexafluoride (SF6) is the most widely used gas for insulation and switching purposes in high voltage and medium voltage applications. Due to its high global warming potential (GWP) and increased environmental awareness the pressure to replace SF6 in high voltage insulation has increased during the past years. A promising alternative to SF6 is the five-carbon perfluorinated ketone C5F10O (C5 PFK). To evaluate its dielectric strength, breakdown experiments were performed in a quasi-homogeneous electric field configuration and with a stepped-DC voltage form. The dielectric performance of SF6, Air, pure C5 PFK and in mixture with Air was analysed. The pressure-reduced electric breakdown field of pure C5 PFK is about double the one of SF6. An Air-C5 PFK mixture at 0.7 MPa has about 95 %…