摘要
直流气体绝缘输电线路(GIL)在长时间电压作用下,内部柱式支撑绝缘子表面易积聚电荷,容易导致绝缘子沿面闪络。因此,研究直流电压下绝缘子表面电荷的积聚特性,对提高直流GIL的绝缘性能和运行可靠性具有重要意义。本文以直流GIL柱式支撑绝缘子为研究对象,设计并搭建表面电荷测量实验平台,引入弱电离气体的迁移扩散方程,利用多物理场有限元分析软件,建立绝缘子-气体复合绝缘结构的表面电荷积聚模型,测量并仿真简化的柱式绝缘子的表面电荷积聚情况,并结合实验和仿真计算结果分析表面电荷积聚成因。同时,建立±800kV直流GIL模型,分析绝缘子的表面电导率、体积电导率和气体的气体电离率对气固界面电场强度和表面电荷积聚的影响。研究深化了直流电压作用下对气-固绝缘界面电荷积聚机理的认识,为直流GIL设备中固体绝缘件的结构设计提供了方法和依据。
Post insulators within DC GIL tend to accumulate surface charge under long-term DC voltage,which easily leads to insulator flashover.Thus,it is important to study the surface charge accumulation characteristics under DC voltage in order to improve the operational reliability of DC GIL.Focusing on the post insulator in GIL,this paper researched its surface charge accumulation characteristics.An experiment platform for surface charge measurement was designed.Through the migration and diffusion equation of weakly ionized gas,the surface charge accumulation model was established by FEM.The surface charges were measured and simulated under the constant temperature condition.The dynamic processes of charge accumulation were analyzed.Meanwhile,the simulation model of±800kV DC GIL was built,and the impacts of the surface conductivity,bulk conductivity and gas ionization rate on the electrical field distribution and surface charge accumulation of post insulator were analyzed.The conclusions deepened the understanding of the charge accumulation mechanism on gas-solid insulation interface under DC voltage,which can provide the methods and references for solid insulation structure design in DC GIL equipment.
作者
田汇冬
李乃一
吴泽华
郭子豪
彭宗仁
Tian Huidong;Li Naiyi;Wu Zehua;Guo Zihao;Peng Zongren(China State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University Xi’an 710049 China;State Grid Zhejiang Electric Power Corporation Research Institute Hangzhou 310014 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2018年第22期5178-5188,共11页
Transactions of China Electrotechnical Society
基金
陕西省2018年重点研发计划(2018ZDCXL-GY-07-03)资助项目
关键词
表面电荷
直流电压
电荷积聚
柱式绝缘子
电场分布
Surface charge
DC voltage
charge accumulation
post insulator
electrical field distribution
