换流母线分段运行对±1100kV特高压直流输电工程的影响  

Effects of Sectionalized Converter Bus Operation on ±1100 kV UHVDC Transmission Project

作　　者：刘心旸[1] 李亚男[1] 邹欣[1] 李高望[1] 

机构地区：[1]国网北京经济技术研究院,北京102209

出　　处：《高电压技术》2016年第3期942-948,共7页High Voltage Engineering

基　　金：国家电网公司科技项目(SGCC[2012]515)~~

摘　　要：依托准东外送特高压直流工程的送端系统,针对换流母线分段断开与分段串联电抗器等抑制短路电流的措施开展研究。首先从系统阻抗角度分析了分段措施减小短路电流的原理;然后基于系统稳态潮流校核了分段前后换流母线短路电流的降低水平,分析了分段位置、串联电抗器阻抗值对抑制效果的影响;最后考虑直流系统运行特性,基于电网等值与交直流电磁暂态仿真建模,全面分析了分段措施对直流主回路设计、无功分组容量以及交流暂态过电压(ACTOV)的影响。研究结果表明分段措施对于限制短路电流效果显著(分段断开措施下三相短路电流降至26 k A),但同时也会引起无功分组投切电压波动的增大(小组波动>1%)以及交流母线避雷器应力的提升(分段串抗措施下避雷器能量升至6.16 MJ),故需要结合工程实际情况以确定是否采用。According to system conditions of Zhundong send-out UHVDC transmission project, we analyzed short-circuit current suppressing measures such as sectional converter bus and segmented series reactor. Firstly, based on system impedance, a principle of sectional measures to reduce short-circuit current was proposed. Then,the decrease level of short-circuit current after converter bus segment was checked based on the system steady flow, and suppressing effects of different segment positions and different series reactor impedance values were tested. Finally, considering DC system characteristics and based on grid equivalence and transient modeling of AC/DC system, the effects of sectional measures on main circuit design, reactive power groups as well as AC transient overvoltage parameters were comprehensively studied and evaluated. Results indicate that sectional measures can limit short-circuit current remarkably（decreasing 3-phase short-circuit current to 26 k A）, but it will also increase voltage fluctuation when switching reactive power group（over 1% when switching small group）, and lift AC bus-bar arrester stress（increasing arrester energy to 6.16 MJ）, so whether or not take the measures should be decided according to actual conditions of certain DC project.

关 键 词：特高压直流 母线分段 短路电流 主回路 无功分组 交流暂态过电压 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM75