输电线路增容改造对三相电压不平衡度的影响研究  

A Study on the Influence of Capacity Expansion on Three-Phase Voltage Unbalance Degree of Transmission Lines

作　　者：王斌 周亮 马梓淇 WANG Bin;ZHOU Liang;MA Ziqi(State Grid Shanghai Electric Power Company,Shanghai 200122,China;State Grid Shanghai Economic and Technological Research Institute,Shanghai 200002,China;Shaanxi Hengju Software Technology Co.,Ltd.,Xi’an 710075,Shaanxi,China)

机构地区：[1]国网上海市电力公司,上海200122 [2]国网上海市电力公司经济技术研究院,上海200002 [3]陕西恒巨软件科技有限公司,陕西西安710075

出　　处：《电网与清洁能源》2023年第9期24-31,共8页Power System and Clean Energy

基　　金：国家电网有限公司科技项目(520900220012)。

摘　　要：采用了通过精确计算交流电阻的方式计算三相电压不平衡度的方法,以220 kV单回路增容改造工程为例,计算了增容导线的允许载流量以及极限输送容量,并分析了输电线路增容改造对三相电压不平衡度的影响。结果表明:旧线路由普通钢芯铝绞线改造为耐热导线后输送容量能够得到显著提升,线路三相电压不平衡度也随之增大,需要对三相电压不平衡度进行重新评估,同时传统近似计算方法相比所提的精确计算方法误差较大,建议针对增容改造工程的三相电压不平衡度计算采用精确计算法。计算方法以及研究结果可为后续输电线路增容改造过程中的交流电阻计算、载流量计算以及三相电压不平衡度计算提供参考。This paper adopts a method of calculating the threephase voltage unbalance degree by accurately calculating the AC resistance.Taking the 220 kV single-circuit capacity expansion project as an example,the allowable flow of the capacity expansion conductor and the ultimate transmission capacity are calculated,and the effect of the transmission line capacity expansion on the three-phase voltage unbalance degree is analyzed.The results show that after the ordinary steel-cored aluminum stranded conductor of the old line is replaced by the heat-resistant conductor,the transmission capacity can be significantly improved,but the threephase voltage unbalance degree will increase accordingly.Therefore,it is necessary to reevaluate the three-phase voltage unbalance degree,and at the same time,as the traditional approximate calculation method has a larger error compared with the accurate calculation method adopted in this paper,it is recommended to use an accurate calculation method for calculating the three-phase voltage unbalance degree for capacity expansion projects.The calculation method and research results of this paper can provide references for the subsequent AC resistance calculation,current capacity calculation,and three-phase voltage unbalance degree calculation in the process of transmission line capacity expansion.

关 键 词：增容改造 耐热导线 三相电压不平衡度 载流量 

分 类 号：TM751[电气工程—电力系统及自动化]