中文摘要：

表面电荷的产生、运动和积累与真空脉冲沿面闪络息息相关，为了探寻沿面闪络的机理，研究了真空ns脉冲作用下环氧及其复合材料的表面电荷特性。围绕15ns／1070ns（脉冲前沿和半高宽）高峰值和165ns／960ns低峰值两种脉冲源，针对纯环氧及其Al（OH）3和TiO2复合材料，测量了ns级脉冲作用前后的表面电位分布。脉冲作用不闪络时，试样将带有正电荷，闪络后，试样表面积累少量负电荷；纯环氧带电量明显高于其复合材料试样；随脉冲作用次数的增加带电量逐渐增加并最终饱和，阴极电位高于阳极。研究认为：脉冲作用下表面电荷积累受电荷注入、二次电子发射及碰撞电离等多种因素影响。闪络通道形成前，二次电子发射和碰撞电离起主要作用；闪络通道形成后，电荷的中和和注入作用占据主导地位。

英文摘要：

In order to analyze the flashover mechanism, we studied the surface charge property of epoxy composite under nanosecond pulsed voltage, and tested the surface charge distribution of epoxy resin and epoxy composite cast with Al（OH）3 and TiO2 , respectively, under two different types of pulsed voltages, namely, 15 ns/1070 ns and 165ns/960ns（referring to the rise time and the half-height width time of the pulse）. The results show that all of the samples are positively charged under the lower pulse and negatively charged under the higher pulse; the surface charge of epoxy resin sample is higher than the other two; the surface charge amount increases with the pulsed voltage acting time and saturates ultimately; the potential of the cathode is higher than the anode. It is concluded that the surface charge characteristic under nanosecond pulse is influenced by the charge injection, the secondary electron emission and the collision ionization and so on. Before the generation of the flashover channel, the secondary electron emission and the collision ionization are the main factors; after the generation of the flashover channel, the charge injection dominates the whole process.