Simulation analysis of arc extinguishing performance of C4F7N/CO2 gas with under impulse arc

Abstract

Currently, the C4F7N/CO2 hybrid gas is regarded as one of the most promising SF6 substitutes. In order to explore the arc quenching capabilities of the C4F7N/CO2 gas mixture, a set of arc energy balance equations is developed in accordance with the arc energy balance theory to determine the change law of overpressure within the arc-quenching pipe with time. In the paper, COMSOL Multiphysics software is used to establish a two-dimensional magneto-hydrodynamic model of the arc quenching structure of the pressure-explosive gas flow lightning gap, and the arc quenching characteristics of the different ratios of C4F7N/CO2 gas mixtures in the pipeline are simulated and analyzed in the condition that the amplitude of the lightning current is 4 kA under the action of the impulse arc. Based on the above method, the change laws of conductivity, velocity and pressure are analyzed in the model by combining the arc energy balance theory. When compared to the theoretical results, it can be shown that 20%C4F7N/80%CO2 extinguishes arcs more effectively than 10%C4F7N/90%CO2 or 5%C4F7N/95%CO2 does, while the arc quenching time is in line with the specifications for air blowing to extinguish arcs.

Keywords

• c4f7n/co2 hybrid gas
• arc quenching capabilities
• arc energy balance theory
• magneto-hydrodynamic model
• impulse arc
• arc quenching time