500 kV交直流同塔输电线路感应电压和电流的多因素分析

Multi Factor Analysis on Induced Voltage and Current of 500 kV AC/DC Transmission Lines on the Same Tower

文中以500 kV张北柔直输电线路工程为研究对象,构建5因素3水平的L16(35)正交试验方案,利用PSCAD/EMTDC软件搭建感应电压与电流的仿真模型,分析了导线排列方式、交直流回路间垂直距离、直流极导线间水平间距、回流线等导线布置方案对带电回路在停运检修线路上感应电压与电流的多因素相互影响程度及规律。结果表明:交直流线路采用上下两层均平行布置时,各感应分量最小,且两极线间感应分量差值亦最小;回流线可降低检修线路上感应电压与电流约35%;影响静电耦合分量因素的因子主次顺序为:垂直间距、运行电压、极导线间水平间距、运行电流;影响电磁耦合分量因素的主次顺序为:运行电流、垂直间距、运行电压、极导线间水平间距;土壤电阻率对停运检修线路的影响可忽略不计。针对静电耦合分量与电磁耦合分量分别提出了不同的优化措施。这为交直流同塔混压共架线路运行、设计以及检修作业方式和人员防护提供依据。

In this paper,the 500 kV Zhang-Bei flexible HVDC transmission line project is taken as an example,the L16(35)orthogonal test scheme with 5-factors and 3-levels is constructed,and the simulation model of induced voltage and current is set up by using PSCAD/EMTDC software.The mutual influence degree and rule of live circuit in outage maintenance line are analyzed,such as conductor layout,vertical distance between AC and DC circuits,the horizontal distance between DC poles and the return line. The results show that in case of adopting parallel layout of upper and lower layers of AC/DC lines,each induction component is the minimum and the difference in the number of induced components between wires of poles is also minimum;The return line can reduce the induced voltage and current of maintenance line by about 35%;The primary and secondary order of the factors affecting the electrostatic coupling component is:vertical spacing,operating voltage,horizontal spacing between poles and conductors as well as operating current;the order of influencing factors of electromagnetic coupling component is:operating current,vertical spacing,operating voltage,horizontal spacing between poles and conductors;And the influence of soil resistivity on outage maintenance line is negligible. In view of the electrostatic coupling component and electromagnetic coupling component,different optimization measures are proposed in this paper.This provides a basis for the operation,design and maintenance of the AC and DC mixed-voltage co-rack line and personnel protection.