±500kV架空线柔性直流电网操作过电压研究  

Switching Overvoltage Research of ±500kV Flexible HVDC Grid With Overhead Line

作　　者：孙栩[1] 陈绍君[2] 黄霆[2] 雷霄[1] 蒋卫平[1] 吴娅妮[1] 陈雁 

机构地区：[1]电网安全与节能国家重点实验室(中国电力科学研究院),北京市海淀区100192 [2]国网福建省电力有限公司电力科学研究院,福建省福州市350007 [3]直流输电技术国家重点实验室(南方电网科学研究院有限责任公司),广东省广州市510080

出　　处：《电网技术》2017年第5期1498-1502,共5页Power System Technology

基　　金：国家电网公司科技项目(±500kV柔性直流电网过电压与绝缘技术研究)

摘　　要：首先介绍了±500 k V架空线柔性直流电网的结构、主要设备的详细参数以及计算所采用的典型故障类型及保护动作时序;其次研究了影响柔性直流电网操作过电压水平的各种关键因素。直流断路器方面,其MOV的额定电压选择为550 k V,从而使直流断路器断口过电压基本处于1.6 pu的水平;直流电网结构方面,"C"字型链式结构下阀底及中性线操作过电压水平较高,而"O"字型结构下直流极线等位置操作过电压水平相对较高,"O-C"字型结构下各处的操作过电压都比较低;直流限流电抗(平抗)的取值会影响直流阀顶或者极母线区域的操作过电压,但是主要功能还是抑制直流故障电流。最后针对±500 k V架空线柔性直流电网的典型故障进行了仿真,总结了柔性直流电网操作过电压水平的初步计算结果,并基于此给出了±500 k V架空线柔性直流电网的换流站设备保护水平的推荐值。Firstly, this paper presents configuration, main device parameters, classic fault types and protection action sequences of±500k V flexible HVDC grid with overhead line. Secondly, key factors influencing its switching overvoltage are investigated. Rated voltage of DC break MOV is 550 k V with corresponding break overvoltage at 1.6p.u.. Switching overvoltage at valve bottom and neutral line is higher for ＂C＂ chain structure, and at DC pole line is higher for ＂O＂ chain structure. Switching overvoltage in all positions is low for ＂O-C＂ chain structure and this configuration is advised in daily operation. Current limiting reactor valves can influence switching overvoltage at valve top and DC pole bus, but their main function is to limit DC fault currents. Finally, classic faults are simulated, and based on this, converter device protection level on ±500k V flexible HVDC grid with overhead line is recommended.

关 键 词：模块化多电平换流器 柔性直流 ±500kV 架空线传输 操作过电压 

分 类 号：TM712[电气工程—电力系统及自动化]