中文摘要：

目前，正在建设和规划的特高压线路大多将经过高海拔地区，沿线复杂的气象条件（气压、湿度）将使输电线路及电力设备的绝缘状况面临严峻的考验。因此，有必要重点研究气压、湿度变化对绝缘介质沿面闪络特性的影响，为特高压输电线路的绝缘设计提供理论依据。通过研究流注放电特性，从放电机制上探讨环境因素（气压、湿度）对沿面闪络特性的影响。在“三电极”结构中，利用光电倍增管测量了不同气压、湿度条件下绝缘介质表面流注传播特性。试验结果表明：流注稳定传播场强分别与气压、湿度成正比例关系；在相同的电场强度下，流注平均传播速度、流注头部发光强度都分别与气压、湿度成反比例关系。因此，流注在低气压、低湿度情况下容易发展，流注稳定传播场强较小，相同电场强度下，流注平均传播速度、流注头部发光强度较大。

英文摘要：

At present, most of the UHV transmission lines, under construction and planning, will pass the high altitude area. The complex weather conditions along the transmission lines will make the insulation condition of the transmission lines and electrical equipment face the ordeal. Therefore, it is necessary to study the infulence of air pressure and humidity on characteristics of flashover along the insulation surfaces. The research results will provide a theory basis for the insulation design of the UHV transmission lines. In the paper, the infulence of environment factors （air pressure and humidity） on characteristics of flashover along the insulation surfaces was discussed through inquiring into the mechanism of streamer discharge. In three-electrode arrangement, the characteristics of streamer propagation along insulation surfaces under the different air pressure and humidity were measured by photomultipliers. The test results show that the streamer stability propagation field is in proportion to air pressure or humidity. Under the same electric field, the streamer propagation velocity or streamer luminous intensity is in inverse proportion to air pressure or humidity. Therefor, It is easier for streamer propagation in the lower air pressure and humidity.The streamer stability propagation field is lower, under the same electric field, the streamer propagation velocity or streamer luminous intensity is higher.