Experimental study on the breaking process of DC hydrogen-nitrogen mixed gas arc

The hydrogen and nitrogen mixed gas arc characteristics are studied in a double contacts chamber, which is detachable, transparent and sealed. The contact diameter is 18 mm and the gap length is 1.5 mm. Images of the arc are taken with a high-speed camera while the arc voltage and current are measured with an oscilloscope for the breaking process. The arc voltage, shape, power and resistance characteristic are then researched with different current, and the evolution of the DC arc is analyzed. In the process of the evolution, each stage is defined and analyzed its characteristics respectively. The relationship between arc-quenching time and the gas diffusion coefficient and current is discussed as well. Finally, the breaking abilities of different arc-quenching dielectrics are comparatively studied in this paper. Experimental and analytical results show that the hydrogen-nitrogen mixed gas has good arc-quenching characteristics because of its higher gas diffusion coefficient and heat conducting coefficient.