Research on follow-current interruption characteristics of gas discharge tube and protective measures

Abstract

If the follow-current interruption time of gas discharge tube is too long, it will lead to short circuit trip of equipment, even breakdown and damage. In order to mitigate the phenomenon and propose corresponding protective measures, the follow-current interruption characteristics of gas discharge tube are studied under different power frequency voltage amplitude and lightning phase polarity in this paper. Required by international standard IEC61000-4-5, the 1.2/50μs and 8/20μs lightning surge combination waves are used to conduct impulse test on gas discharge tube. For the most rigorous experimental results, the method of series connection with varistor is used in order to suppress the follow-current phenomenon of gas discharge tube. Through the analysis of the experimental results, it is found that: the initial rising rate of voltage and follow-current interruption time are positively correlated with the power frequency voltage amplitude; the initial rising rate of voltage and follow-current interruption time increase in the first half cycle and decrease in the latter half cycle with the increase of the lightning pulse phase in each half power frequency cycle; the initial polarity of the follow-current glow voltage is consistent with the polarity of the lightning pulse, and the initial polarity of the follow-current arc voltage is consistent with the polarity of the power frequency period of the pulse; it can effectively suppress the follow-current phenomenon and reduce the residual voltage that using gas discharge tube in series with varistor whose voltage is less than its direct-current breakdown voltage. The conclusion of this paper has a certain guiding role for the parameter selection of gas discharge tube.