Abstract:SF6/N2 discharge parameters used in fluid model were obtained by two-term Boltzmann equation analysis. Combined finite element method with flux corrected transport method, breakdown voltages of SF6/N2 were calculated by loop iterative solutions of streamer discharge processes. The gas discharge experiments in uniform electric field were simulated to prove the computation accuracy, where the gas gap is 5mm and gas pressure is between 0.1~0.6MPa. Based on the computed and experimental data, synergistic effect coefficients of SF6/N2 in different pressures and mixing ratios were obtained, which were used to analyze the accuracy of above computing method in synergistic effect study. Breakdown properties below 0.1MPa were further studied for a more comprehensive reflection of mixed SF6/N2 application conditions. Results show that electron number density in discharge gap increases rapidly with electron avalanche moving forward, and growth rate of SF6 is slower than that of SF6/N2. Peak electron number density of 20%SF6/80%N2 in 0.1MPa reaches 4.6×1014m-3 at 5ns, while it is only 3.7×1012m-3 in SF6. When the gas pressure is in 0.1~0.6MPa, the maximum error of the calculated and measured breakdown voltages of SF6/N2 is 9.23%. The trends of calculated synergistic effect coefficients with pressures and mixing ratios are consistent with the experimental results, and the average error is 5%. The trends of breakdown voltages and synergistic effect coefficients with pressures and mixing ratios in 0.02~0.08MPa are similar to those in 0.1~0.6MPa.
李鑫涛, 林莘, 徐建源, 李璐维, 陈会利. SF6/N2混合气体电击穿特性仿真及实验[J]. 电工技术学报, 2017, 32(20): 42-52.
Li Xintao, Lin Xin, Xu Jianyuan, Li Luwei, Chen Huili. Simulations and Experiments of Dielectric Breakdown Characteristics in SF6/N2 Gas Mixtures. Transactions of China Electrotechnical Society, 2017, 32(20): 42-52.
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