220kV城市长电缆线路护层环流及抑制措施研究  

Study on Sheath Circulating Current and Suppression Measures of 220 kV Urban Long Cable Line

作　　者：李炬添 李志宇 林睿 金作林 张振 陈小月 LI Jutian;LI Zhiyu;LIN Rui;JIN Zuolin;ZHANG Zhen;CHEN Xiaoyue(China Energy Engineering Group Guangdong Electric Power Design Institute Co.,Ltd.,Guangzhou 510663,China;State Key Laboratory of Power Grid Environmental Protection China Electric Power Research Institute,Wuhan 430074,China;State Grid Chongqing Electric Power Company Urban Power Supply Branch,Chongqing 400000,China;School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China)

机构地区：[1]中国能源建设集团广东省电力设计研究院有限公司,广州510663 [2]中国电力科学研究院有限公司电网环境保护全国重点实验室,武汉430074 [3]国家电网有限公司重庆市电力公司市区供电分公司,重庆400000 [4]武汉大学电气与自动化学院,武汉430072

出　　处：《内蒙古电力技术》2024年第6期64-71,共8页Inner Mongolia Electric Power

基　　金：中国能源建设集团广东省电力设计研究院有限公司科技标准化项目“近海深水区海上风电电气关键技术研究”(EV05011W)。

摘　　要：针对高压电缆金属护层电压不平衡引起护层环流超限,影响城市电网安全稳定运行,导致电缆线路报警停运的问题,对220kV城市长电缆线路交叉互联单元中不均匀分段、不同三相轴间距以及混合排列所导致的护层环流进行分析计算,引入不均匀分段系数评价不均匀分段程度对护层环流的影响,并进行工程实例验证。结果表明,仿真模型和计算结果准确性良好;单回路和双回路下,护层环流大小与不均匀分段系数成正比;均匀分段下,同一组交叉互联单元中采用不同轴间距或混合排列方式会导致护层环流增大。提出利用不同轴间距抑制不均匀分段下环流的方法,如通过较短段采用较大轴间距、较长段采用较小轴间距来减小护层环流。Aiming at the problem that the voltage imbalance of metal sheath of high voltage cables causes the over-limit of sheath circulating current,which affects the safe and stable operation of urban power grids and leads to the alarm shutdown of cable lines,the sheath circulating current due to uneven segmentation,different three-phase axial spacings,and mixed arrangement in the cross-interconnection of 220 kV urban long cable lines is analyzed and calculated,and influence of segmentation degree on the sheathing circulation is evaluated by introducing the uneven segmentation factor,and validated by engineering examples.The results show that the simulation model and calculation results have good accuracy;the size of the sheathing circulation is proportional to the uneven segmentation coefficient of the cable cross-connections for single and double circuits;the use of different axle spacings or mixed arrangements in the same group of cross-connections will lead to an increase in the sheathing circulation under uniform segmentation.It is proposed to utilize different axis spacing to suppress the circulation under uneven segmentation,such as by using larger axis spacing for shorter segments and smaller axis spacing for longer segments to reduce the sheathing circulation.

关 键 词：220KV电缆 交叉互联 护层环流 不均匀分段 三相轴间距 

分 类 号：TM757[电气工程—电力系统及自动化]