3D打印构筑随机表面微结构调控绝缘的真空沿面闪络特性

Tailoring the Vacuum Flashover Characteristics of Insulation by 3D Printed Random Surface Microstructures

表面形貌调控被认为是提升真空绝缘闪络电压的有效举措之一,但常用表面粗化技术的效果具有较高的随机性,可控的调控方法和制备技术仍是亟需解决的技术难题。为此,采用基于路径追踪算法的仿真手段获得二次电子产率(secondary electron yield,SEY)可调的随机微结构表面;利用立体光固化成型3D打印技术实现了随机微表面结构的精准制备;通过闪络电压及表面电荷特性的表征手段,结合仿真结果,系统分析了表面形貌参数对闪络的影响。结果表明:改变表面形貌参数可以设计出SEY可调的微结构表面;分析认为,微结构通过影响电子与材料表面的碰撞过程,对二次电子倍增及表面电荷积聚行为产生影响,进而对闪络电压产生影响;改变表面形貌参数可以有效调控绝缘子的闪络强度,SEY越小闪络电压越高(最大差距达92.7%)。研究成果有望为真空绝缘系统中的固体绝缘设计提供新的思路。

Controlling surface morphology is regarded as one of effective measures for the enhancement of vacuum flashover strength.However,due to the high randomness of the conventional surface roughening methods,effective control method and fabrication procedure are still lacking and requires further investigation.Therefore,a simulation method based on the path-tracking algorithm was used to obtain secondary electron yield(SEY)-tunable random microstructure surface.The precise preparation of the random microstructures was realized by 3D printing of stereolithography apparatus.The influences of surface morphology on surface flashover strength and surface charge behaviors in vacuum were investigated systematically.The results reveal that the microstructure surface with adjustable SEY can be designed by changing the morphology parameters.It is concluded that the microstructure plays an important role in the secondary electron multipactor and surface charge accumulation by means of influencing the electron-surface interaction,hence affecting the flashover voltage.The flashover of insulation can be effectively tailored by changing the surface morphology parameters.The smaller the SEY,the higher the flashover voltage(the maximum difference is 92.7%).The research results are expected to provide a new idea for future solid insulation design in vacuum insulation systems.