Study on the Pulsed Flashover Characteristics of Solid-Solid Interface in Electrical Devices Poured by Epoxy Resin

• Published in: Plasma science & technology Vol. 16; no. 9; pp. 856 - 860
• Main Author: 李曼苹 吴锴 杨战平 丁曼 刘鑫 成永红
• Format: Journal Article
• Language: English
• Published: 01.09.2014
• Subjects: Breakdown; Devices; Dielectrics; Electrodes; Epoxy resins; Fingers; Flashover; Solid-solid interfaces; 同轴电极; 固体电介质; 固体界面; 改性环氧树脂; 电极系统; 电气设备; 闪络特性; 高电压脉冲
• ISSN: 1009-0630
• DOI: 10.1088/1009-0630/16/9/09

In electrical devices poured by epoxy resin, there are a lot of interfaces between epoxy resin and other solid dielectrics, i.e. solid-solid interfaces. Experiments were carried out to study the flashover characteristics of two typical solid-solid interfaces （epoxy-ceramic and epoxy~ PMMA） under steep high-voltage impulse for different electrode systems （coaxial electrodes and finger electrodes） and different types of epoxy resin （neat epoxy resin, polyether modified epoxy resin and polyurethane modified epoxy resin）. Results showed that, the flashover of solid-solid interface is similar to the breakdown of solid dielectric, and there are unrecoverable carbonated tracks after flashover. Under the same distance of electrodes, the electric stress of coaxial electrodes is lower than that of finger electrodes; and after the flashover, there are more severe breakdown and larger enhanced surface conductivity at interface for coaxial electrodes, as compared with the case of finger electrode. The dielectric properties are also discussed.