摘要
多回直流共用接地极,其中一回接地极线路开展检修工作,另一回直流恰处于单极大地运行时,运行电流经接地极入地,其中部分电流流入检修侧杆塔接地装置,通过杆塔、检修接地线以及接地极线路流入换流站接地网,对换流站内设备及人身安全产生影响。以鱼龙岭极址土壤参数为基础,利用电力系统接地分析软件CDEGS计算分析了鱼龙岭共用接地极一回直流单极大地运行(额定电流),另一回直流接地极线路检修时,经由杆塔接地装置、永久/临时接地线、接地极线路以及换流站接地网共同构成的回路最终流入换流站接地网的电流可能引起的跨步电压、接触电压等人身安全风险,评估了换流站变压器直流偏磁风险。计算结果表明,接地极线路检修时流入接地网的电流不会引起人身安全风险,但会造成穗东站变压器偏磁电流超标。
For common grounding electrode, if one of the lines is being maintained and another is under mono-polar earth operation, operating current will flow into the ground and be picked up partly by tower at overhaul side, which will finally flow into the grounding grid of converter station through lines and affect the equipments and personal safety in converter station.In this paper, personal safety risks such as stepping voltage and touch voltage caused by the current flowing into the grid of converter station during the line maintenance of Yulongling common grounding electrode are calculated and analyzed, and DC bias of transformers in converter station is evaluated with the power system grouding analysis software CDEGS under monopole grounding operating mode with rated current.Results show that the current flowing into the grounding grid during the line maintenance are unable to cause personal safety risks but may result in the excess of transformers bias current in Suidong converter station.
作者
李瑞显
胡上茂
罗炜
蔡汉生
张义
LI Ruixian;HU Shangmao;LUO Wei;CAI Hansheng;ZHANG Yi(State Key Laboratory of HVDC Transmission Technology, Electric Power Research Institute, CSG, Guangzhou 510663, China;China Southern Power Grid Co., Ltd., Guangzhou 510663, China)
出处
《南方电网技术》
CSCD
北大核心
2019年第7期58-63,共6页
Southern Power System Technology
基金
南方电网科学研究院科技项目“直流共用接地极相互影响及解决方案研究”(SEPRI-K175003)~~
关键词
共用接地极
线路检修
直流偏磁
人身安全
common grounding electrode
line maintenance
DC bias
personal safety
