干式直流套管极板边缘电场分布及优化方法  

Electric Field Distribution and Optimization Method at Screen Edge of RIP DC Bushing

作　　者：陈铭 刘轩东[1] 张锐 梁成军 张乔根[1] 汤浩 李金忠 CHEN Ming;LIU Xuandong;ZHANG Rui;LIANG Chengjun;ZHANG Qiaogen;TANG Hao;LI Jinzhong(State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China;China Electric Power Research Institute,Haidian District,Beijing 100192,China;State Grid Corporation of China,Xicheng District,Beijing 100031,China)

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049 [2]中国电力科学研究院有限公司,北京市海淀区100192 [3]国家电网有限公司,北京市西城区100031

出　　处：《电网技术》2021年第1期381-388,共8页Power System Technology

基　　金：国家电网有限公司科技项目(GYB17201600207)。

摘　　要：干式直流套管作为换流变、阀厅的重要组成部分,极板边缘的电场最大,局部放电最易从该处起始,进而引发绝缘失效,如何有效优化极板边缘处的电场已经成为提高干式直流套管运行可靠性的关键。为进一步确定干式直流套管极板边缘电场分布规律及优化方法,建立了双层电容屏套管芯体模型,分析了不同电容屏参数下传统经验公式的准确性,并对比了铝箔边缘半折边、敷设半导电绝缘纸、敷设非线性电导材料等方法对极板边缘电场的优化效果。结果表明,传统经验公式对极板边缘的最大电场估计偏小,且偏差基本不随d/Δt变化,约为7.5%。此外,极板边缘半折边方法可以使极板边缘曲率半径增大1倍,最大电场降低27.8%。极板边缘敷设环氧浸纸材料电导率10~100倍的半导电纸可以使极板边缘最大电场降低超过31.4%,且再增大半导电纸电导率,极板边缘最大电场几乎不再下降。极板边缘附着非线性绝缘材料方法是一种有前景的方法,可以使极板边缘最大电场下降达73.2%。As a critical part of the transformer and valve hall, resin impregnated paper(RIP) DC bushing has the largest electric field at the screen edge, from which the partial discharge is easy to start, causing insulation failure. How to effectively optimize the electric field at the screen edge has become one of the keys to improve the operating reliability of the RIP DC bushing. To further determine the distribution law and the optimization method of electric field at the screen edge of RIP bushing, the bushing core model with double capacitor layers was established, and the accuracy of traditional empirical formula under different parameters was analyzed. The optimization effects of having the screen edge half-folded, laying semi-conductive insulating paper or non-linear conductive material on the electric field at the screen edge were compared. The results show that the tradition theoretical formula has a small estimation of the maximum electric field at the screen edge, with its deviation about 7.5% and basically unchangeable with d/Δt. Also, the curvature radius of the screen edge can be doubled, and the maximum electric field can be reduced by 27.8% by using the screen edge half-folded method. When semi-conductive paper with its conductivity 10~100 times the RIP material is laid on the screen edge, the maximum electric field can be reduced by more than 31.4%, and the maximum electric field almost no longer decreases with the increase the conductivity of the semi-conductive paper. The method of attaching non-linear insulating material to the screen edge is promising, which can reduce the maximum electric field by 73.2%.

关 键 词：干式直流套管 极板边缘 模型修正 电场优化 

分 类 号：TM14[电气工程—电工理论与新技术]