Equivalence between C5F10O Addition and PTFE Vapor Contamination in the Particle Composition and Critical Electric Field Strength of High-Temperature CO2/O2 Gas Mixture

SF6 has been introduced as an insulating and extinguishing gas in gas circuit breakers. However, its global warming potential is significantly high at approximately 25 200. Therefore, development of alternative gases is essential. We have been investigating the dielectric breakdown characteristics of high temperature CO2 gas contaminated by various gases. This study discusses the equivalent condition between high temperature CO2/O-2/C5F10O gas mixture and CO2/O-2 gas mixture contaminated with PTFE (-C2F4-) vapor because both gas mixtures consist of C, O, and F atoms. It is concluded that when the mole fractions of every atom are equivalent between both gas mixtures, both gas mixtures have the same characteristics as each other, such as the particle composition and critical electric field strength. (c) 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.