交直流复合电压下的稍不均匀场高压电极起晕特性  

Corona Onset Characteristics for Electrodes of Slightly Non-uniform Electric Field Under Composite AC-DC Voltage

作　　者：齐磊[1] 张静岚 符瑜科 徐永生 卞星明[1] 罗兵[3] 

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206 [2]国网冀北电力有限公司电力科学研究院,北京100045 [3]中国南方电网科学研究院,广州510080

出　　处：《高电压技术》2017年第9期2991-2997,共7页High Voltage Engineering

基　　金：国家自然科学基金(51277065)~~

摘　　要：为研究复合电压下阀内部屏蔽罩电极的起晕电压特性,搭建了用稍不均匀电场电极缩尺模拟阀用屏蔽罩电极,并搭建了复合电压电极电晕放电平台,基于紫外成像技术研究了稍不均匀场中阀用屏蔽罩电极缩尺模型的紫外光子数特性及起晕电压特性,并获得了不同电极尺寸下的起晕电压的变化规律。在此基础上,利用有限元方法对不同交直流配比下,电晕起始电场强度分布进行了仿真。通过分析可以得到:气隙间距在0~10 cm范围内,在固定直流改变交流的复合升压方式下,随着正直流分量的增加,电极所加交流分量会逐渐降低,若认为起晕时交直流分量直接线性叠加得到的电压为起晕电压,则起晕电压值会随正直流分量的增加呈现先增加后降低的趋势,存在一组交流和直流电压配比,使得复合电压作用下电极的起晕电压达到峰值,数值可达65 k V左右。该研究可以为换流阀内电极结构的绝缘优化设计提供参考。In order to study the characteristics of corona inception voltage for valve internal electrodes under composite voltages, the corona experimental platform under composite AC-DC composite voltages was established for scaled model of valve shield electrode which was treated as electrode generating slightly non-uniform electric field. By ultraviolet imaging technology, the corona ultraviolet photon count characteristics and corona inception voltage characteristics of electrode was studied, and the variation of corona inception voltage under different electrode geometric sizes was also obtained. Furthermore, the electric field distribution of the electrodes at the corona point under different AC-DC ratios was achieved by finite element electric simulation. In the range of air gap of 0~10 cm, it can be found from the results that the AC component decreases with the increase of positive DC component when the electrode is at the corona inception point. Besides, if the linear superposition value of the two components is treated as the corona onset voltage, the onset voltage first increases and then decreases with the increase of the positive DC component. There exists a set of AC and DC voltage ratio that can make the highest added value of AC and DC components, which can be 65 k V. The research of this paper can provide reference for the insulation optimization design of the electrode structure of converter valve.

关 键 词：复合电压 阀用屏蔽罩缩尺模型 紫外光子数 起晕电压 电场仿真 

分 类 号：TM721.1[电气工程—电力系统及自动化]