Breakdown Characteristic of N 2 -CO 2 Gas Mixtures under AC and DC Test Voltages

• Published in: Journal of physics. Conference series 2021-05, Vol.1874 (1), p.12027
• Main Authors: Sham, N M B, Zahid, N Z, Kamarudin, M S, Jamail, N A M, Abd-Rahman, R
• Format: Article
• Language: English
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/1874/1/012027

This study provides fundamental knowledge on the breakdown properties of N 2 -CO 2 gas mixture with a ratio of 20:80, 50:50, and 80:20. The gas mixtures were tested under HVAC and HVDC voltages with 1 bar (abs) pressure. The plane-plane and needle-plane electrodes were used with gap lengths between 0.5 cm to 2.5 cm. It is found that the breakdown voltage of N 2 -CO 2 mixture increased with the increased of CO 2 content. The breakdown voltage is also affected by the increment of gap distance for both electrode geometrics; plane-plane to represent the uniform field and needle-plane as the non-uniform field. The gas under uniform field configuration has a higher ability to withstand higher voltage levels compared under non-uniform field configuration. However, the non-uniform field provides a very high electric field intensity, which implies very high electric field stress. By increasing the percentage CO 2 in N 2 -CO 2 mixture, the insulation strength can reach about 64% that of pure SF 6 gas at the 0.1 MPa.