为提供触发型3电极开关导通时延定量分析估算的辅助方法,基于电子崩发展和流注理论推导了导通时延的数值计算模型。模型中,用场强是否满足Raether击穿判据中形成流注的条件来解释不同导通机制下开关的击穿。为验证该导通时延模型,研制了1个3电极开关,测试了其导通性能,并讨论了不同工作参数对其导通时延的影响。典型实验结果为在高的欠压比条件下更容易使开关工作在直接导通模式下。此外,实验与仿真结果表明,时延曲线可由2个欠压比拐点划分为3个区域。第1个拐点是开关导通进入可靠击穿的欠压比下限值,第2个拐点则为开关导通机制转化的拐点值。研究结果表明,基于开关的工作可靠性考虑,开关工作欠压比的合理范围是0.5~0.7,可作为触发型气体开关设计的参考依据。
In order to offer assistance for the quantity estimation and analysis of time delay of three-electrode trigatron switches,a numerical model of the time delay was derived based on the electronic avalanche development theory and the streamer theory.In the model,whether the electrical field satisfied the Raether breakdown criterion for streamer formation was proposed to explain the difference of breakdown modes.To verify the mathematical model,a three-electrode trigatron gap was fabricated,and its characteristics in dry air were determined experimentally.Moreover,the influence of some different parameters on the gap’s breakdown time was discussed,and it was found the gap more likely worked in directly breakdown mode.The experimental results and analysis demonstrate that the delay time curve can be divided into three regions by two inflection points of under-voltage ratio.The first inflection point is the low limit of under-voltage ratio for reliable breakdowns,and the second one is a transition point of the gap’s breakdown mechanism.Considering the working reliability,the experimental results show that the operating voltage range of 0.5~0.7 is reasonable,providing a reference for design of three-electrode trigatron switches.