Fundamental Properties of CO₂ Gas as an Arc Quenching Medium and Thermal Interruption Performance of Full-Scale GCB Model

Abstract

Fundamental properties of CO₂ gas, as an alternative arc quenching medium of SF₆ gas, in a puffer-type gas circuit breaker were investigated theoretically and experimentally, focusing particularly on its thermal interruption performance. It was found that utilizing arc energy for enhancing puffer pressure is a good solution to construct a CO₂ gas circuit breaker due to the physical properties of CO₂ gas. Based on these fundamental investigations, the 72kV-31.5kA-class CO₂ gas circuit breaker model, which does not contain SF₆ gas at all, was designed, manufactured, and tested. As a result, the CO₂ gas circuit breaker model achieved the specified interruption performance for short line fault.