Characteristics of perfluoromethyl vinyl ether: A new eco-friendly alternative gas for SF6

The exploration of eco-friendly insulating gas to substitute the most potent greenhouse gas sulphur hexafluoride (SF₆) has consistently garnered significant attention. Herein, the authors evaluated the feasibility of utilising perfluoromethyl vinyl ether (PMVE, C₃F₆O) as a new branch of eco-friendly insulating gas for the first time. The primary dielectric and stability characteristics of PMVE regarding AC breakdown, partial discharge, dielectric recovery, and decomposition properties were revealed under various gas pressure and electrical field conditions. It was found that PMVE demonstrated superior dielectric strength, with the AC breakdown and PD inception voltage (PDIV) 1.10 and 1.14 times that of pure SF₆. Furthermore, the dielectric strength of PMVE exhibits stability even after undergoing 100 cycles of AC breakdowns, and there is no observable formation of solid precipitation on the electrode surface. The discharge decomposition of PMVE mainly generates fluorocarbon (CF₄, C₂F₆, C₃F₆, C₃F₈, etc.) and CO. Overall, the exceptional insulation stability and no absence of solid precipitation features endow PMVE to be utilised as a new eco-friendly gas for SF₆-free gas-insulated equipment.