Numerical Simulation of the Discharge Dynamics of C₄F₇N-N₂ and the Influence of Buffer Gas

Feng Wang,Chijie Zhuang,Lipeng Zhong,Qiuqin Sun,Lanbo Wang,She Chen

doi:10.1109/tps.2021.3085316

Abstract

Due to the greenhouse effect of SF 6 , the search for new environmentally friendly substitute gases has become an urgent task for the electrical industry. In this article, we have employed a 2-D fluid model to study the characteristic of streamer discharges in the C 4 F 7 N-N 2 mixture. The discharge process and insulation performance of the C 4 F 7 N-N 2 mixture with different C 4 F 7 N content are compared under the same conditions. In a5.07% C 4 F 7 N-N 2 mixture, the streamer expands continuously and reaches the top boundary quickly. In 7% and 13.1% C 4 F 7 N-N 2 mixture, the streamer is gradually stagnated in the simulation domain. The streamer radius shows a decreasing trend, and a low electron density area appears behind the streamer head as the streamer moves forward. The streamer discharge simulation in 50% SF 6 -50% N 2 is also performed to compare its insulation performance to the C 4 F 7 N-N 2 mixture. The results show that the discharge is suppressed more heavily in 13.1% C 4 F 7 N-N 2 than in 50% SF 6 -50% N 2 . The influence of buffer gas is studied by comparing the discharge process in C 4 F 7 N-N 2 and C 4 F 7 N-CO 2 with 13.1% C 4 F 7 N content. It is found that the discharge is more easily to a breakdown in C 4 F 7 N-CO 2 than that in C 4 F 7 N-N 2 in our simulation configuration. The simulation provides a way to optimizing the buffer gas ratio of new environmentally friendly gases from a microscopic perspective.

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