摘要
Electrical tree degradation is one of the main causes of insulation failure in high-frequency transformers.Electrical tree degradation is studied on pure epoxy resin(EP)and MgO/EP composites at frequencies ranging from 50 Hz to 130 kHz.The results show that the tree initiation voltage of EP decreases,while the growth rate and the expansion coefficient increase with frequency.Moreover,the bubble phenomenon at high frequencies in EP composites is discussed.Combined with trap distribution character-istics within the material,the intrinsic mechanism of epoxy composites to inhibit the growth of the electrical tree at different frequencies is discussed.It can be concluded that more deep traps and blocking effect are introduced by doping nano-MgO into EP bulks,which can improve the electrical tree resistance performance of EP composites in a wide frequency range.
基金
National Natural Science Foundation of China,Grant/Award Number:92266110
Natural Science Foundation of Fujian Province,Grant/Award Number:2022J01112
the Project of State Key Laboratory of Power System and Generation Equipment,Grant/Award Number:SKLD22KZ10。
作者简介
Correspondence:Yunxiao Zhang,Email:zhangyxthu@163.com,ORCID:https://orcid.org/0000-0002-8734-4505;Correspondence:Yuanxiang Zhou,Email:zhouyx@tsinghua.edu.cn。
