±800kV与±500kV换流站共用接地极时入地电流对极址附近电位分布的影响  

Influence of Ground-Return Current of ±800kV and ±500kV Converter Stations Sharing a Common Grounding Electrode on Potential Distribution

作　　者：张富春[1] 郭婷[2] 黎晓辰 周文俊[2] 黄海[1] 喻剑辉[2] 

机构地区：[1]中国南方电网有限责任公司超高压输电公司广州局,广州市510400 [2]武汉大学电气工程学院,武汉市430072

出　　处：《电力建设》2014年第7期115-120,共6页Electric Power Construction

基　　金：南方电网公司科技项目(K-GY2012-031)

摘　　要：±800 kV楚穗直流换流站与±500 kV兴安直流换流站所共用的鱼龙岭接地极其中一回线路检修,另一回线路单极大地回路运行时,极地附近10 km范围内的电位分布决定了检修线路的检修措施;利用CDEGS软件计算了接地极附近电位分布,并与该极址投运前系统调试期间的测量结果进行了对比。结果表明:单回线路检修,另一回线路单极大地回路运行时,接地极内外环上方呈地表电位峰值,且接地极内环上方地电位高于外环,接地极外环地电位衰减迅速;跨步电压也在极环处达到峰值,但小于设计值,接触电压按标准采取措施后可满足限值要求;实测结果与计算结果基本一致;因土壤电阻率较低使得跨步电压偏高的部分区域,检修作业时应采取相应的防护措施。The potential distribution near the Yulongling electrode site within 10 km when a grounding line in converter stations sharing a DC common grounding electrode is being maintaining while the other one is under monopolar ground-return mode, has a directly relationship to the maintenance work of Chusui±800 kV DC transmission engineering and Xing＇an ±500 kV DC transmission engineering. The potential distribution near the grounding electrode site was researched by using software CDEGS and the research results were compared with the actual measurements during the system debugging. The results show that in the above operating case, the peak distribution occurs above the electrode site＇s inner ring and outer ring, and the ground potential above the inner ring is higher than that above the outer ring, which decays rapidly. The step voltage peak is also at the rings but less than the design value, and the contact voltage can meet the limit requirement according to the standard measures. The actual measurements and calculated results are basically consistent except that the step voltage value in some area is high due to the low soil resistivity, so the maintenance operation in this area should take appropriate protective measures.

关 键 词：共用接地极 单极大地回路运行 地表电位分布 跨步电压 接触电压 线路检修 

分 类 号：TM862[电气工程—高电压与绝缘技术]