直流电压下油纸复合绝缘电场分布对击穿特性的影响  

Influence of Electric Field Distribution on Breakdown Characteristics of Oil-paper Composite Insulation Under DC Voltage

作　　者：宋翰林 黄猛 姚园鑫 尤玮光 应宇鹏 吕玉珍[4] SONG Hanlin;HUANG Meng;YAO Yuanxin;YOU Weiguang;YING Yupeng;LÜYuzhen(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China;Jiaxing Power Supply Company of State Grid Zhejiang Electric Power Co.,Ltd.,Jiaxing 314000,China;Taizhou Power Supply Company of State Grid Zhejiang Electric Power Co.,Ltd.,Taizhou 318000,China;School of Energy Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]新能源电力系统全国重点实验室(华北电力大学),北京102206 [2]国网浙江省电力有限公司嘉兴供电公司,嘉兴314000 [3]国网浙江省电力有限公司台州供电公司,台州318000 [4]华北电力大学能源动力与机械工程学院,北京102206

出　　处：《高电压技术》2023年第12期4938-4947,共10页High Voltage Engineering

基　　金：北京市自然科学基金(3212035);国家自然科学基金联合基金(U1866603)。

摘　　要：油纸复合绝缘击穿是换流变压器的主要绝缘故障之一,但是油纸复合绝缘电场分布与击穿特性之间的量化关系研究较少。通过添加TiO_(2)纳米粒子调节油纸复合绝缘的电场分布与击穿特性,采用电声脉冲法测量了油纸复合绝缘中的电场分布,搭建了基于光电倍增管和罗氏线圈的击穿过程光-电联合观测平台,并提出了融合扩展Debye模型和界面势垒限制电流的油纸复合绝缘等效模型。结果发现:纳米粒子引入的松弛极化过程和浅陷阱使界面电荷密度增大,油纸复合绝缘击穿过程的光-电信号时差和击穿电压的极性效应与原来完全相反,其原因在于油纸复合绝缘电场分布改变导致击穿的起始位置不同;所提模型能较好反映夹层介质极化电流、电场分布和击穿电压的极性效应之间的关联关系,并且计算结果与实测结果较相符,验证了模型的有效性。该研究可为换流变压器绝缘结构设计和油纸复合绝缘材料改性提供指导。Breakdown of oil-paper composite insulation is one of the main insulation faults of converter transformer.The quantitative relationship between electric field distribution and breakdown characteristics of oil-paper composite insula-tion is rarely studied.In this paper,the electric field distribution and breakdown characteristics of oil paper composite insulation are adjusted by TiO_(2) nanoparticles.The electric field distribution in oil-paper composite insulation is measured by a pulsed electro-acoustic method.A combined measurement platform of light and current for breakdown process based on photomultiplier tube and Rogowski coil is built,and an equivalent model of oil-paper composite insulation with ex-tended Debye model and interface potential barrier limiting current is proposed.The results show that the interface charge density is increased by the relaxation polarization process and shallow traps introduced by nanoparticles,thereby the time difference of light and current signal and the polarity effect of breakdown voltage in the breakdown process of oil paper composite insulation are completely opposite to the original.The reason is that the initiation position of breakdown is dif-ferent due to the change of electric field distribution of oil paper composite insulation.The proposed model can better reflect the relationship among the polarity effects of polarization current,electric field distribution and breakdown voltage of sandwich dielectric.And the calculated results are in good agreement with the measured results,which verifies the ef-fectiveness of the model.The result can provide guidance for the insulation structure design of converter transformer and the modification of oil-paper composite insulation materials.

关 键 词：油纸绝缘 界面势垒 光电联合 Debye模型 电场分布 击穿 TiO_(2)粒子 

分 类 号：TM855[电气工程—高电压与绝缘技术] TM41