地磁感应电流在直流输电系统引发的谐波不稳定分析  

Analysis of Harmonic Instability in DC Transmission System Due to Geomagnetic Induced Currents

作　　者：褚优群[1] 彭晨光[1] 刘连光[1] 

机构地区：[1]华北电力大学电气与电子工程学院,北京102206

出　　处：《电网与清洁能源》2009年第9期11-15,22,共6页Power System and Clean Energy

基　　金：国家自然科学基金项目(50677020);国家"863计划"项目(2007AA04Z425)

摘　　要：高压直流(HVDC)输电换流器两侧的谐波阻抗对确定地磁感应电流(GIC)引发的谐波有重要意义。对比了有外部激发和无外部激发2种情况下HVDC换流变的直流偏磁机理,并根据三端口网络模型计算、等效出的谐波阻抗,研究了在GIC作用下换流变偏磁后的谐波水平。PSCAD/EMTDC仿真表明,GIC激发的谐波取决于系统的谐波阻抗。当直流输电系统对某次谐波存在谐振点或呈现高阻抗时,可导致系统谐波明显放大,严重时会引起直流输电工程闭锁。The harmonic impedance on two sides of converters in HVDC transmission system is important in determinating the harmonics due to GIC （geomagnetic induced currents）.This paper compares two kinds of mechanism about the HVDC converter transformer magnetic DC bias with external excitation or not, and studies the harmonic level produced by the converter transformer due to GIC according to the calculated and equivalent harmonic impedance by three-port network model. PSCAD/EMTDC simulation results prove that harmonic level induced by GIC depends on the harmonic impedance, and harmonics could be obviously amplified and even block the HVDC transmission project, if there are resonance points or the system presents high impedance to certain harmonic.

关 键 词：高压直流输电 等值阻抗 谐波不稳定 

分 类 号：TM732[电气工程—电力系统及自动化]