Breakdown Characteristics of C5F10O/N2 Mixtures in a Uniform Field Under AC Voltage

In this article, ac breakdown characteristics of
$\text{C}_{5}\text{F}_{10}\text{O}/\text{N}_{2}$
mixtures under a uniform field with different concentrations of C5F10O, gap distances, and pressures are studied and compared to that of SF6. Additionally, the Paschen curves and insulation strength of the mixed gases are obtained. Results show that the insulation strength of 2% C5F10O/98% N2, 5% C5F10O/95% N2, 8% C5F10O/92% N2 mixtures can reach approximately 70%, 75%, and 80%, respectively, of SF6 under 0.5 MPa. Since the liquefaction temperature of C5F10O is 26.9 °C at 0.1 MPa, the available options for concentrations and pressure of C5F10O mixtures in practical applications are considered. 2% C5F10O/98% N2 under 0.6 MPa with the minimum allowable temperature (−20 °C) is approximately 81% of the insulation strength of SF6 at 0.5 MPa. The Weibull distribution is applied to analyze experimental data to provide a reliable reference for the insulation application of
$\text{C}_{5}\text{F}_{10}\text{O}/\text{N}_{2}$
mixtures. It is shown that the
$\text{C}_{5}\text{F}_{10}\text{O}/\text{N}_{2}$
mixture is a reasonable alternative for SF6 in electrical equipment.