摘要
为探明干式空心电抗器包封绝缘材料在分子层面的热老化机理,本研究在180℃下对环氧/玻璃纤维复合材料进行了336 h的加速热老化试验,并采用红外光谱、介电谱及交流电气强度测试表征老化后环氧/玻璃纤维复合材料的官能团、分子链段运动、活化能及交流电气强度演变特性。模拟计算并探讨了老化过程中化学结构变化及分子链段运动特性演变导致的活化能下降对交流电气强度的影响。结果表明:老化过程中会产生大量以酯基、酮基为主的羰基基团和小分子链。这些小分子链和极性基团会极大增加环氧基体内部自由体积和自由电子数量,使链段运动逐渐增强,活化能降低,最终导致绝缘性能大幅下降。
To investigate the thermal ageing mechanism of dry air core reactor encapsulated insulating materials at the molecular level,this study conducted 336-hour accelerated thermal ageing tests on epoxy/glass fiber composites at 180℃.The evolutionary characteristics of functional groups,molecular chain segment motions,activation energies,and AC electric strength of the epoxy/glass fiber composites after ageing were characterized by infrared spectroscopy,dielectric spectroscopy,and AC electric strength test.The effect of the decrease in activation energy caused by the changes in chemical structure and the evolution of molecular chain segment movement properties during ageing on the AC electric strength was investigated.The results show that a lot of carbonyl groups and small molecular chains dominated by ester and ketone groups generate during the ageing process.These small molecule chains and polar groups greatly increase the free volume and the number of free electrons inside the epoxy matrix,so that the chain segment movement is gradually enhanced and the activation energy is reduced,which ultimately leads to a significant reduction in insulation capacity.
作者
张健
王鹏飞
李中原
刘骥
刘贺千
杨洪达
ZHANG Jian;WANG Pengfei;LI Zhongyuan;LIU Ji;LIU Heqian;YANG Hongda(Electric Power Research Institute,State Grid Heilongjiang Electric Power Company Limited,Harbin 150030,China;Key Laboratory of Engineering Dielectrics and Its Application,Ministry of Education,Harbin University of Science and Technology,Harbin 150080,China)
出处
《绝缘材料》
北大核心
2025年第7期121-128,共8页
Insulating Materials
基金
国家电网公司总部科技项目(5108-202218280A-2-338)。
