单芯交流海缆不同接地方式下的损耗计算及对载流量的影响研究  

Loss Calculation and Influence on Ampacity of Single-core AC Submarine Cable Under Different Grounding Modes

作　　者：刘英[1] 肖阳[1] 苏宇[1] 姜爽[2] LIU Ying;XIAO Yang;SU Yu;JIANG Shuang(Xi＇an Jiaotong University,Xi＇an 710049,China;State Grid Beijing Electric Power Company,Beijing 100031,China)

机构地区：[1]西安交通大学,西安710049 [2]国网北京市电力公司检修分公司,北京100031

出　　处：《高压电器》2018年第10期56-62,共7页High Voltage Apparatus

摘　　要：为保障单芯交流海缆的运行安全,海缆线路除在两端牢固接地外,有时还需将金属护套和铠装进行分段短接或采用半导电护层,3种接地方式对电缆传输容量的影响尚未有定量分析结论。文中针对大长度平行直线敷设的高压单芯非磁性铠装海底电缆线路展开讨论,建立了金属护套及铠装环流计算的等效模型,采用2种方式对半导电护层的损耗进行评估,在IEC标准基础上,提出了电缆允许载流量的修正计算公式。以交流500 kV充油海缆工程为对象进行了定量计算,结果表明,文中算法可以准确计算海缆线路的允许载流量;3种接地方式对电缆的允许载流量没有显著影响;为避免电流过大导致的加速老化,建议选择电阻率不小于106Ω·m的半导电护层材料。For the safety of single-core AC cable circuit, submarine cables can be grounded in three ways. Besides both-ends solid bonding, intermediate short-circuit or semi-conductive over-sheath between metal sheath and armour are usually used for long circuit. The influence of bonding technique on transmission capacity has not been quantitatively researched. Long single-core HV submarine cables with non-magnetic armour are studied in this paper. The equivalent models for the circulating current calculation of metal sheath and armour are established. The loss of semi-conductive over-sheath is evaluated by two methods. The revised formulas for cable rating are presented based on IEC standards. After the theoretical analysis and modeling, a case study is carried out on a 500 kV oil-filled AC cable project. Quantitative calculations show that the allowable ampacity of submarine cables can be determined accurately by the algorithm proposed. The selection among the three bonding techniques has no significant influence on the cable rating. The resistivity of semi-conductive over-sheath is suggested to be no less than 106Ω·m, so as to avoid accelerated aging.

关 键 词：单芯交流海缆 金属护套接地方式 环流损耗 半导电护层 允许载流量 

分 类 号：TM75[电气工程—电力系统及自动化]