Measurement of sparkover voltage and time lag characteristics in CF3I–N2 and CF3I– air gas mixtures by using steep‐front square voltage

Abstract

AbstractA square pulse voltage is useful for studying electrical discharge physics or very fast transient overvoltage issues. This paper describes sparkover voltages and time lag (V– t) characteristics of CF3I gas, which has very low environmental effects and high dielectric strength, and its mixtures with nitrogen gas or air in a very short time range below a microsecond. They are measured by using a steep‐front square voltage with a rise time of 16 ns and a peak value of 200 kV. Pure CF3I gas has 20% higher dielectric strength than SF6 gas. The V– t characteristics of CF3I–N2 or CF3I– air gas mixtures, which contain 60% CF3I gas, are equivalent to those of pure SF6 gas at the same total pressure. A quantitative evaluation of V– t characteristics by the equal‐area criterion is also performed. The equal‐area parameter which is obtained by applying a voltage high enough to make the formative time lag dominant should be chosen. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(2): 1–7, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20325