同塔双回不换位线路电压不平衡度研究  

Study on voltage imbalance of un-transposed double-circuit lines on the same tower

作　　者：朱庆钢[1] 刘前进[1] 陈海涛[1] 罗龙波[1] 何德龙[1] 韦胜旋[1] 曾繁源[1] 花欢欢[2] 

机构地区：[1]华南理工大学电力学院,广东广州510640 [2]智能电网运行与控制湖南省重点实验室(长沙理工大学),湖南长沙410004

出　　处：《电力系统保护与控制》2014年第7期73-79,共7页Power System Protection and Control

摘　　要：在线路走廊特别紧张的地区,部分线路可能没有条件采用完全换位,而同塔多回输电线路中采用不换位架设将导致电力系统三相参数不对称。针对这个问题,以某地区一条750 kV同塔双回线路为例,对该线路不平衡度计算进行了理论推导,并应用PSCAD/EMTDC软件从杆塔类型、相序排列方式、回间距离、线路长度几个方面对线路不平衡度进行了仿真分析。仿真结果表明,输电线路较短时采用同塔同窗逆相序方式架设并适当调整回间距离,能将电压不平衡度控制在一定范围内。输电线路过长时则需采取换位措施,避免对系统造成不良影响。Transmission lines in some areas may have no condition to transposition completely, because of a shortage of line corridor. And un-transposed multi-circuit transmission lines will cause electrical three-phase parameters asymmetry. To solve this problem, this paper takes a 750 kV double circuit lines without transposition for an example, and the formulas of calculating the voltage imbalance on double-circuit lines are presented. Using PSCAD/EMTDC, the zero-sequence voltage unbalance and negative sequence voltage unbalance are calculated in different types of towers, different phase sequence arrangement, different distance between the two loops and different line length. According to the simulation results, when the transmission line is short, the voltage imbalance can be controlled within a certain range by adopting with the reverse phase sequence in the same tower window, which loops distance is adjusted properly. To avoid bad effect on the power system, transmission line must be transposed when the line is long.

关 键 词：同塔双回 不换位 输电走廊 不换位线路 电压不平衡度 相序排列 

分 类 号：TM75[电气工程—电力系统及自动化]