长距离大容量特高压输电线路甩负荷分闸过电压的限制措施比较研究  

Comparative Study on Measures to Limit Load-Rejection Opening Overvoltage of Long-Distance and Large-Capacity UHVAC Transmission Lines

作　　者：李杨[1] 周浩[1] 沈扬[2] 孙可[3] 

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027 [2]浙江省电力设计院,浙江省杭州市310012 [3]浙江省电力公司,浙江省杭州市310007

出　　处：《电网技术》2013年第12期3564-3570,共7页Power System Technology

基　　金：国家重点基础研究发展计划项目(973项目)(2011CB209405)~~

摘　　要：以长距离、大容量特高压双端输电系统为模型，分别探讨了增加线路平均分段数即仅采用金属氧化物避雷器fmetaloxidearrester，MOA）和高抗来限制过电压的方法和在线路分段数较少的情形下加装断路器分合闸电阻的方法对甩负荷类分闸过电压的限制效果，并对2种限制措施进行了经济性的评价。结果表明，2种限制措施下的分闸过电压水平最大相差约为0．04pu，限制过电压效果基本相同。通过采取NDI：i线路分段数的措施，能够限制单相接地甩负荷分闸过电压，但是所需开关站数目较多，投资费用较大；而采取加装分合闸电阻的措施可以较少的线路分段数来达到同样有效控制过电压的目的，同时减少线路分段数进而减少开关站的数目，可节省投资费用数亿元，甚至最大达10亿元。研究表明，分闸电阻值最佳为600～700Q。因此，建议对长距离大容量的特高压输电线路可以考虑采取加装分合闸电阻的措施。Based on the model of long-distance and large-capacity UHVAC line with double-end source, two different methods are used to limit overvoltage and the economical evaluation of the two methods are given. One of them is increasing the number of average subsections of transmission line, namely the overvoltage is limited by only adopting metal oxide arrester （MOA） and HV shunt reactor when opening and closing resistors are not used, and the another one is to limit load-rejection opening overvoltage by adding opening and closing resistors to circuit breakers. Simulation results show that the maximum difference of opening overvoltage levels by the two limiting measures is about 0.04 p.u., so the effects of limiting overvoltage by the two methods are basically the same. Through the measure of increasing subsection number of transmission line the load-rejection opening overvoltage under single-phase earth fault can be limited, however the number of required switching stations is more, so the investment cost is high; through adding opening and closing resistors the same purpose of effectively limiting the overvoltage by lesser subsection number of transmission line can be achieved, meanwhile the number of switching stations can be reduced due to decreasing of the number of subsections of transmission line, so hundreds of millions RMB can be saved, and even the highest saved investment cost may be up to 1 billion RMB. Study results also show that the best value of opening resistor is within the range from 600 to 700 , thus to limit load-rejection overvoltage it is suitable for long-distance and large-capacity transmission lines to add opening and closing resistors.

关 键 词：UHVAC 甩负荷分闸过电压 线路分段 分合闸 电阻 限制措施 投资费用 

分 类 号：TM863[电气工程—高电压与绝缘技术]