多回输电线路下单芯电力电缆护套感应电压和环流计算分析  

Calculation Analysis of Induced Voltage and Circulating Current in Sheath of Single-Core Power Cable Applied under Transmission Lines

作　　者：张嘉乐[1] 吴耀辉[1] 

机构地区：[1]中国南方电网深圳供电局,广东深圳518000

出　　处：《电气技术》2016年第8期50-54,73,共6页Electrical Engineering

摘　　要：110kV及以上等级的电缆一般采用单芯结构。为了限制电缆护套上的工频感应电压及环流,往往采用金属护套单端接地或金属护套交叉换位互联两端接地联接形式。理论计算和实际运行经验表明三相交叉互联两端接地均匀分段下电缆护套感应电压和护套环流较小。随着城市电力输电线路和高压电力电缆不断增多,高压电力电缆面临复杂的电磁环境,尤其是多回输电线路下单芯电力电缆护套感应电压和环流偏大,严重影响电力电缆的运行。关于多回输电线路下高压埋地电力电缆护套感应电压和环流的计算和分析,鲜有相关研究报道。本文通过建立电力电缆的护套环流和护套感应电压计算模型,进行了多回输电线路下高压埋地电力电缆护套感应电压和护套环流的实例计算。通过实例分析多回输电线路埋地单芯电力电缆的护套影响。计算分析表明多回输电线路的存在显著增大电缆护套感应和护套环流,与实际测量结果一致。The power cable applied in l l0kV and above level generally adopts single-core structure. In order to limit the inducted voltage on the cable sheath and circulating currents, the cable is usually grounded by single-ended metal sheath or interconnection between three-phase sheaths. Theoretical calculation and practical operation experience shows that three-phase interconnection cables grounded at both ends enjoy smaller induced voltage and circulating currents. With the growing of the power transmission lines and high voltage power cable in cities, the high voltage power cable faces complex electromagnetic environment. The cable suffers serious induced voltage and circulating currents especially under high voltage transmission lines, which resulting the accelerated aging. There is few related research about how to calculate the induced voltage and circulating currents in the cable applied nearby the high voltage transmission lines. This paper established a model to calculate the induced voltage and circulating currents in the cable applied nearby the high voltage transmission lines. The calculation analysis shows that transmission lines significantly increase induced voltage and circulating currents.

关 键 词：单芯电缆 感应电压 环流 

分 类 号：TM75[电气工程—电力系统及自动化]