计及金属回流线影响的±500kV高压直流输电线路地面合成电场计算分析  

Calculation and Analysis of Ground-Level Total Electric Field under ±500kV HVDC Lines Considering the Influence of Metal Return Lines

作　　者：郝黎明 王东来 卢铁兵 陈博 王振国 Hao Liming;Wang Donglai;Lu Tiebing;Chen Bo;Wang Zhenguo(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China;Research Institute of State Grid Zhejiang Electric Power Company Hangzhou 310014 China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京102206 [2]国网浙江省电力有限公司电力科学研究院,杭州310014

出　　处：《电工技术学报》2019年第12期2468-2476,共9页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划资助项目(2016YFB0900900)

摘　　要：针对张北±500kV柔性直流电网示范工程采用的架空金属回流线的线路结构,使用上流有限元法,首次计算并分析金属回流线对±500kV线路地面合成电场的影响。为了考虑一极导线电位悬浮的工况,提出一种合成电场中导体悬浮电位的计算方法。搭建室内缩尺实验平台来验证计算方法的有效性。基于仿真计算,获得了金属回流线对单回双极线路、单回单极运行线路、同塔双回线路地面合成电场的屏蔽特性。为了提高金属回流线对地面电场的屏蔽效果,单回线路的回流线对地投影应在无回流线时地面合成电场峰值上方附近。与单回线路相比,由于同塔双回线路的回流线数量多、间距大,回流线对地面电场强度屏蔽效果更为明显。The structure of overhead metal return lines is adopted in the±500kV voltage source converter(VSC)-based direct current grid demonstration project in Zhangbei.In this paper,the influence of metal return lines on the ground-level total electric field of±500kV lines was studied for the first time by the upstream finite element method.A calculation method for the floating potential in total electric field was proposed to consider the operating condition that one pole is floating.The effectiveness of calculation method was verified by establishing a reduce-scale experimental platform in the lab.The shielding characteristics of metal return lines on ground-level electric field were analyzed under single circuit bipolar lines,single circuit unipolar operating lines and double circuit lines on the same tower.In order to improve the shielding effect of single circuit lines,the projection of return lines to the ground should be near the peak value of total electric field without return lines.Compared with single circuit lines,the shielding effect of double circuit lines is significantly improved because of the increasing number and large space of return lines.

关 键 词：高压直流输电 合成电场 金属回流线 电场屏蔽 悬浮电位 

分 类 号：TM721.1[电气工程—电力系统及自动化]