【摘要】 长期以来真空沿面闪络现象一直制约着真空绝缘材料性能的提高,极大地限制了高功率脉冲设备的小型化和实用化进程。该文针对环氧基复合材料引入真空绝缘的背景,研究了脉冲电压作用下,复合材料的表面陷阱状况对其沿面绝缘特性的影响。通过对Simmons等温电流理论的进一步推导,完善了利用表面电位衰减测量材料表层陷阱能量分布的理论和方法,并分析了填料浓度对于材料表层陷阱的影响机制。在已有的二次电子发射雪崩(SEEA)闪络模型基础上,强调了深电子陷阱在沿面闪络过程中的作用,并定性分析了此过程中的物理机制和影响因素。复合材料中的深陷阱对于抑制材料表面的内二次电子发射有一定的作用,通过提高深陷阱的密度可以在一定程度上提高沿面闪络电压。更多还原

【Abstract】 Surface flashover phenomena in vacuum has seriously restricted the improvement of insulating strength,which greatly limit the miniaturization and practicality of pulsed power devices with high density.On the basis of epoxy composite material being introduced into vacuum insulation system,the paper investigated the effects of trapping parameters of composite insulating material on its surface insulation strength.The isothermal relaxation current(IRC) proposed by Simmons was further deduced,the measurement theory and method of energy distribution of surface trapping centers based on surface potential decay was perfected,and the influence mechanism of filler concentration on trapping parameters was also analyzed.Considering the current secondary electron emission avalanche(SEEA) flashover model,the role of deep electron traps during the flashover growing was emphasized,and the physical mechanism and affecting factors of the process were analyzed qualitatively.It is suggested that,the deeper electron traps can restrain the emission of internal secondary electrons inside the surface layer of material,and the surface flashover voltage is possible to be promoted by enhancing the density of deeper traps.更多还原