大电流条件下气体火花开关电极烧蚀的研究进展

Review of Electrode Erosion in a Spark Gap Switch Under Large Pulsed Currents

气体火花开关在各类脉冲功率装置中应用广泛,但放电产生的热等离子体将对电极材料产生烧蚀,烧蚀产物(金属蒸汽、液滴等)也会对开关绝缘造成污染,影响开关工作特性、缩短开关寿命,因而受到特别关注。在过去几十年间,国内外学者针对电极烧蚀机理及其影响因素开展了广泛研究,得到了常见电极材料在不同放电条件下的烧蚀特征;近年来,随着材料科学与诊断技术的进步,电极烧蚀研究集中在新型电极材料与烧蚀表征两方面。为此回顾了不同实验条件下电极烧蚀现象的相关研究,描述了电极烧蚀的基本特征,归纳了影响烧蚀的主要因素,介绍了电极与绝缘子表面烧蚀形貌的测试方法,介绍了电极烧蚀产物表征与分析的实验方法,论述了电极烧蚀对开关工作特性的影响规律。最后,分析并提出了电极烧蚀的一般评估方法,指出了电极烧蚀研究的热点问题和发展方向,对今后继续深入开展该领域的研究工作具有一定借鉴意义。

Spark gaps are widely adopted in various pulsed power equipment. However, thermal plasmas with high temperature and heat flux will erode electrode materials. Furthermore, erosion products(metallic vapor or liquid drops) will cause the degradation of the switch’s insulation. Special attention has been paid on this topic since the electrode erosion and insulation degradation can affect the operating characteristics and lifetime of switch. In the last few decades, scholars have made a systematic investigation on erosion mechanisms and influence factors. Erosion performance of different electrode materials has been obtained. Recently, as the development of material science and diagnostics, research on electrode erosion becomes more comprehensive and explicit, with two research focuses on novel electrode materials and erosion characterization. This paper reviews the research on electrode erosion under different conditions. Erosion features are depicted and influencing factors are summarized. Meanwhile, methods for analyzing erosion morphology and erosion products are introduced. In addition, the influence of electrode erosion on the operating characteristics is clarified. At last, a general framework for evaluating electrode erosion is proposed, and research focus and orientation of electrode erosion are mentioned as well. It is hoped this work will offer a better understanding of electrode erosion phenomenon and act as a reference for related research and applications.