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

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.