G/E在液氮和变压器油中的雷电冲击沿面闪络特性对比

摘要

As the voltage level of super conducting power devices increasing,the significance of the study on flashover characteristics in liquid nitrogen becomes more and more important.Glass fiber reinforced epoxy composite material(G/E)is an important insulating and supporting material for HTS device.For deeper exploring the surface flashover characteristics in liquid nitrogen,the differences of flashover voltages,flash over time and flashover traces for G/E material are compared under different voltage applied methods in liquid nitrogen and transformer oil by experiments.It is believed that because of the different characteristics of liquid nitrogen and transformer oil,there would have different stresses caused by temperature shock on the surface of solid dielectric and differences on forming process,constituents and decomposition product of gas layers when flashover in the two environments.Those are the main reasons of different flashover phenomenon in the two environments.By the method of contrastive analysis,the impulse surface flashover characteristics in liquid nitrogen are deeper explored,the results could provide principle reference for dielectric design of HTS devices.%随着超导电力装置电压等级的提高,研究液氮中沿面闪络特性的意义愈加重要.玻璃纤维增强环氧树脂复合材料(G/E)是应用于超导设备的重要绝缘和支撑材料.为了深入探索液氮中冲击沿面闪络过程的特性,通过实验,比较液氮和变压器油两种环境中不同电压施加方式下,G/E的闪络电压、放电时延和闪络痕迹的不同特点.经分析可知,变压器油和液氮环境两种介质本身特性的不同,造成两种环境中沿面闪络时材料表面温度骤变产生应力的不同,以及气化层形成过程、成分和分解产物的不同,从而造成两种环境中沿面闪络表现出不同的特性.通过对比,进一步揭示了液氮中冲击沿面闪络的特性,为超导电力装置的绝缘设计提供了原理参考.