Effect of Polymer Ablation Gas on Arc Quenching Properties around Current Zero

Abstract

Influence of polymer ablation on arc properties such as temperature distribution and arc conductance in current decay process was investigated by numerical approaches. A numerical thermofluid model was developed for a simplified circuit breaker with POM or PTFE ablation. In this model, thermal plasma-polymer solid coupling phenomena such as melting and evaporation were taken into account without any empirical model based on measurements unlike other existing numerical thermofluid model. Dominant process for decay of arc conductance was examined by changing thermodynamic parameters such as melting and boiling temperatures of solid polymers, or thermal conductivity and electrical conductivity of ablation gas. As a result, it was found that gas density, thermal conductivity and electrical conductivity of ablation gas were more effective for decaying arc conductance than any other thermodynamic parameters.