非全线并行架设的共用走廊高压输电线路电气不平衡度及其影响因素分析  

Analysis of Electrical Unbalance Degree and Its Influence Factors of Multi-circuit Transmission Lines with Partially Parallel Erection in Right-of-way

作　　者：朱军[1] 吴广宁[1] 张龙伟[1] 曹晓斌[1] 杨琳[2] 任志超[3] 

机构地区：[1]西南交通大学电气工程学院,成都610031 [2]国网四川省电力公司电力科学研究院,成都610072 [3]国网四川省电力公司经济技术研究院,成都610094

出　　处：《高电压技术》2014年第12期3942-3952,共11页High Voltage Engineering

基　　金：铁道部重大专项课题(2011T008-D);国家电网公司科技项目(2011-WG-4)~~

摘　　要：为研究非全线并行架设的共用走廊(ROW)高压输电线路电气不平衡度,分析了共用走廊内特高压同塔双回线路(UHVDLST)不平衡电流的产生原因及影响因素。采用PSCAD/EMTDC建立了ROW超/特高压交流线路模型,对影响UHVDLST电气不平衡度的主要因素进行仿真分析。结果表明:接近段长度、数量和接近段内输电线路的输送功率对ROW高压输电线路电气不平衡度具有较大影响。随着接近段长度的改变,UHVDLST零序不平衡度mI0、mII0和穿越性零序不平衡度mt0、环流性零序不平衡度mc0的变化较大;随着接近段数量的改变,mI0和mt0的变化较大。当UHVDLST同为轻载时,其电气不平衡度较大;而当其同为重载时,其电气不平衡度较小。对于额定输送功率较大的线路,当其实际输送功率变化时,UHVDLST的电气不平衡度将发生明显改变。对于非全线并行架设、且具有一定长度接近段的高压输电线路,应根据ROW输电线路电气不平衡度合理选择接近段长度,限制接近段数量和各接近段内输电线路的数量,并将ROW内输电线路输送功率的相对比值控制在较低水平。In order to research the electric unbalance of high-voltage transmission lines erected partially parallel in right-of-way（ROW）, we analyzed the generation unbalance current and its influential factors in ultra-high-voltage double-circuit lines on the same tower（UHVDLST）. Hence we built a model of UHV AC transmission line in ROW using PSCAD/EMTDC and investigated the main factors determining the unbalance degree of UHVDLST. The results show that the length and number of nearby sections, as well as the active power of transmission lines in nearby sections, significantly affect the unbalance degree. When the length of nearby section varies, the zero-sequence unbalance degrees of UHVDLST（mI0, mII0）, the through zero-sequence unbalance degree mt0,and the circulative zero-sequence unbalance degree mc0 will vary greatly; mI0 and mt0 will vary with the number of nearby sections as well. The unbalance degree is large when UHVDLST operates with light loads, while it is small when UHVDLST operates with heavy loads. Moreover, for a transmission line with large rated power, variation in its active power leads to obvious variation in the electric unbalanced degree of UHVDLST. For a transmission line erected partially parallel in ROW and with a nearby section of certain length, the nearby section＇s length should be set according to the electrical unbalance degree, the number of nearby sections and the lines in each nearby section should be limited, and the relative ratio of active power（divide the power on UHVDLST into the power on the other lines in the ROW） should be limited at a low level.

关 键 词：输电走廊 特高压同塔双回线路 电磁耦合 不平衡度 换位方式 相序排列 

分 类 号：TM75[电气工程—电力系统及自动化]