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CF3I has been widely considered as a potential alternative for SF6,because it has low global warming potential(GWP)but an insulation capability that is 1.2 times greater than that of SF6.In this paper,the electron swarm parameters of CF3I and its gas mixture with N2,including the effective ionization coefficient and electron drift velocity,are examined theoretically through the Boltzmann equation method in the condition of steady-state Townsend(SST)experiments.Based on the derived data of the limiting field strength of CF3I-N2gas mixture,taking into consideration of environmental aspects such as GWP,ozone depletion potential(ODP),liquefaction temperature and toxicity,we studied the possibility of applying the gas mixture as the insulation medium in gas-insulated switchgears(GIS)or cubic type gas-insulated switchgears(C-GIS).It is found that CF3I-N2gas mixtures contained 30%~70%CF3I perform comprehensively better than pure SF6and compressed N2,and especially in medium and low voltage environments,the boiling point of CF3I-N2gas mixture meets the domestic and global requirements in mid-low latitude regions.Therefore we conclude that the gas mixture is acceptable for replacing SF6as the insulation medium in C-GISs. 相似文献
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CF_3I is a potential SF_6 alternative gas.In order to study the insulation properties and synergistic effects of CF_3I/N_2 and CF_3I/CO_2 gas mixtures,two-term approximate Boltzmann equations were used to obtain the ionization coefficient α,attachment coefficient η and the critical equivalent electrical field strength(E/N)_(cr).The results show that the(E/N)_(cr)of CF_3I gas at 300 K is 1.2 times that of SF_6 gas,and CF_3I/N_2 and CF_3I/CO_2 gas mixtures both have synergistic effect occurred.The synergistic effect coefficient of CF_3I/CO_2 gas mixture was higher than that of CF_3I/N_2 gas mixture.But the(E/N)_(cr)of CF_3I/N_2 is higher than that of CF_3I/CO_2 under the same conditions.When the content of CF_3I exceeds 20%,the (E/N)_(cr) of CF_3I/N_2 and CF_3I/CO_2 gas mixture increase linearly with the increasing of CF_3I gas content.The breakdown voltage of CF_3I/N_2 gas mixture is also higher than that of CF_3I/CO_2 gas mixture in slightly non-uniform electrical field under power frequency voltage,but the synergistic effect coefficients of the two gas mixtures are basically the same. 相似文献
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触头的电寿命是断路器研究比较关心的~项内容,传统的断路器电寿命评估方法是统计开断电流的大小与次数,从而估算出电磨损。这种方法用在触头电寿命的在线监测却不够准确。以小波理论作为工具,提出了在线监测燃弧时间的方法,改进了触头电寿命评估的理论,并为断路器电寿命的在线监测提供了一条新思路。 相似文献
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对前列腺射频热疗技术中的一些关键技术,如频率、电极形状等进行了试验和分析,认为13.56MHz频率的效果最好,临床识疗证明了本文的试验分析。 相似文献