Study on Thermal Interruption and Dielectric Recovery Performance of CO2/O2/C4-FN Mixture in HVCB

The eco-efficient SF6-free high voltage switchgear is one of the most significant revolution towards the future green power grids. In recent decade, the dielectric mixture of CO2/O2/C4FN has demonstrated huge potential as an alternative to SF6. The research on the characteristics of dielectric withstands and arc extinguishing of CO2/O2/C4-FN mixture and the development of corresponding SF6-free switchgear technology have attracted increasing attentions and gained rapid progress [1][2]. In this paper, we present our study on the thermal interruption and dielectric recovery performance of CO2/O2/C4-FN mixture based on a model high voltage circuit breaker. The thermal interruption capability was quantified in terms of the highest falling slope (di/dt) of the injected current that could be…