Theoretical study of the decomposition mechanism of C5F10O in the presence of Cu vapor

Abstract

C5F10O is one of the promising SF6 replacements in power switchgears due to its low global warm potential and high dielectric strength. As Cu metal evaporated by discharges and overheat faults in power switchgears will change the decomposition mechanism and products of C5F10O, the interaction between C5F10O and Cu vapor is important to evaluate the arc-quenching behavior but seldom reported yet. Therefore, this paper is focused on the impacts of Cu vapor, mainly released from the contacts in circuit breakers, on the decomposition mechanism and products of C5F10O. The molecular geometries, harmonic vibrational frequencies, and energetic information of products, reactants, and transition states in C5F10O + Cu decomposition pathways including 19 reactions were calculated by density functional theory. The main decomposition reactions and products were selected based on the analysis of rate constants. This work is hopeful to evaluate the arc-quenching behavior of C5F10O-insulated power equipment considering the evaporation from Cu contacts.