Dielectric strength of breakdown voltage of Nitrogen and Carbon-dioxide

This paper presents the investigations on AC, DC and Negative lightning Impulse breakdown voltages and leakage currents of Nitrogen (N₂) and Carbon-dioxide (CO₂) in nonuniform electric field. The sphere-plane electrodes have been applied. The sphere radius is 2.5, 10 and 20 mm. The gap distance is varied from 2.5 to 20 mm. and the gas pressure from 0.5 to 2 bars. According to the experiments, the breakdown voltages of N₂ are higher than those of CO₂ for both AC and DC in all condition. The Negative lightning Impulse breakdown voltage of CO₂ are higher than N₂. Furthermore in case of AC voltage, the capacitive displacement current flows in both N₂ and CO₂ are quite the same. However, in case of DC voltage, corona occurs and the negative corona current is higher than the positive one in both N₂ and CO₂.