对真空绝缘问题中“场致增强系数”概念的研究  

Research on the Concept of Field Enhancement Factor in Vacuum Insulation Investigation

作　　者：丁健刚 刘志远[2] 彭在兴 李元钊 穆圣泉 DING Jian-gang;LIU Zhi-yuan;PENG Zai-xing;LI Yuan-zhao;MU Sheng-quan(Electric Power Research Institute,CSG,Guangzhou 510663,China;State Key Laboratory of Electrical Insulation and Power Equipment,Department of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]南方电网科学研究院有限责任公司,广东广州510663 [2]西安交通大学电气工程学院电力设备电气绝缘国家级重点实验室,陕西西安710049

出　　处：《真空电子技术》2023年第5期50-56,共7页Vacuum Electronics

基　　金：国家重点研发计划项目(2022YFB2403700)。

摘　　要：本文的目标是研究真空绝缘问题中,较高的场致增强系数所可能对应的实际电极表面几何形貌。通过耦合基于波函数阻抗法的热-场致发射电流密度计算、基于电子轨迹法的空间电荷计算和微凸起内的电磁热计算,建立了电极表面微凸起的热-场致发射计算模型。通过对比具有相同场致增强系数的单个微凸起和多个叠加微凸起,发现更可能引起真空击穿的是单个的尖锐微凸起的高场致增强系数,而非多个具有较小场致增强系数的微凸起组合产生的高场致增强系数。结合本文的计算结果和文献中的实验、计算结果,发现原子级微观缺陷导致的局部逸出功下降,是实验测定出不合理的较高场致增强系数最有可能的原因。The research objective is to study the actual electrode surface geometry may correspond to high field enhancement factor in vacuum insulation.By coupling the thermal-field emission current density calculation based on quantum mechanics wave impedance method,the space charge density calculation by electron-trace method,and the electromagnetic-thermal calculation inside the micro-protrusions,a complete thermal-field emission model of micro-protrusion on cathode surface is established.By comparing the calculation results of several combined micro-protrusion and a single sharp micro-protrusion with the same total field enhancement factor,it is found that the single sharp micro-protrusion is more likely to induce a vacuum breakdown.By combing our calculation result with experimental and calculation results from references,it is found that reduced local work function resulted by atomic scale defects is the most possible reason for the unreasonably high field enhancement factor measured in some experiments.

关 键 词：真空绝缘 热-场致发射 场致增强系数 

分 类 号：TM561.2[电气工程—电器]