双回并行敷设高压电缆零序护层电流计算及负荷相序优化方法  

Calculation of Zero-sequence Sheath Current and Load-phase Sequence Optimization Method for Double-circuit Parallel Laying High-voltage Cables

作　　者：苑玉宽 李华春 任志刚 郭卫 鲁海亮[1] 蓝磊[1] YUAN Yukuan;LI Huachun;REN Zhigang;GUO Wei;LU Hailiang;LAN Lei(School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China;China State Grid Beijing Electric Power Research Institute,Beijing 100000,China;State Grid Beijing Electric Power Company,Beijing 100000,China)

机构地区：[1]武汉大学,武汉430072 [2]国网北京市电力公司,北京100000 [3]国网北京电力科学研究院,北京100000

出　　处：《电瓷避雷器》2022年第3期123-132,共10页Insulators and Surge Arresters

摘　　要：随着城市电网电缆化率不断提高,同隧道内两回高压电缆并行敷设的线路日益增多。由于两回线路间的互相影响,可能会引起电缆护层电流过大,危及电缆安全运行。针对目前双回电缆护层电流特征并不明确的问题,建立了双回电缆护层电流计算模型,分析得到了双回电缆护层电流具有幅值相位都相同的零序特征。应用建立的模型对某双回电缆线路不同负荷时的护层电流进行了计算,计算结果与工程实测结果误差不超过9.2%,解释了该线路护层接地电流异常的原因。对不同相序下护层电流与负荷电流之间的关系进行了研究,结果表明:在两回电缆不同的负荷电流组合下,护层电流最小对应的相序可能是不同的,提出了考虑负荷电流变化的最优负荷相序选取方法。With the continuous improvement of the cable utilization rate of urban power grid, there are more and more circumstance that two high-voltage cables laid in parallel in the same tunnel. Due to the mutual influence between the two circuits, the cable sheath current may be too large, endangering the safe operation of the cable. Aiming at the problem that the current characteristics of double circuit cable sheath are not clear at present, the calculation model of double circuit cable sheath current is established, and the zero sequence characteristics of double circuit cable sheath current with the same amplitude and phase are obtained. The model is applied to calculate the sheath current of a double circuit cable line under different loads. The error between the calculated results and the measured results is no more than 9.2%. The reason for the abnormal sheath grounding current of the line is explained. The relationship between sheath current and load current under different phase sequences is studied. The results show that under different load current combinations of two cables, the phase sequence corresponding to the minimum sheath current may be different. The selection method of optimal load phase sequence combination considering the variation range of load current is proposed.

关 键 词：高压电缆 双回路 零序电流 护层电流 相序组合 

分 类 号：TM75[电气工程—电力系统及自动化]