换流变压器铁心饱和型谐波不稳定分析  

Analysis Saturation Harmonic Instability of Converter Transformer

作　　者：刘洪涛[1] 周剑[1] 梅琪 梅勇[1] 林福昌[2] 李化[2] 孟佳 涂静芸 LIU Hongtao;ZHOU Jian;MEI Qi;MEI Yong;LIN Fuchang;LI Hua;MENG Jia;TU Jingyun(China Southern Power Grid Dispatching Control Center,Guangzhou 510530,China;School of Electrical and Electronic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]中国南方电网电力调度控制中心,广州510530 [2]华中科技大学电气与电子工程学院,武汉430074

出　　处：《高压电器》2021年第12期191-194,200,共5页High Voltage Apparatus

摘　　要：介绍了高压直流输电系统中2次谐波的传递过程,以及由此可能引发的谐波不稳定性。针对变压器绕组中存在的直流电流而导致的2次谐波电流进行了仿真分析研究,得出了励磁电流中2次谐波幅值与直流电流的关系。2次谐波幅值与直流电流的关系由线性系数X体现,从换流变压器阀侧看入交流系统侧的阻抗与变压器变比N以及线性系数X相关,相关系数为(1/N-3/2X),线性系数X与变压器的额定励磁电流I_(m)呈负相关。结果表明,当额定励磁电流I_(m)<0.089%时,此时(1/N-3/2X)<0,将可能发生谐波不稳定现象。The transmission process of secondary harmonic in HVDC transmission system and harmonic instability caused by it are introduced. The secondary harmonic current due to DC current in the transformer winding is simulated,analyzed and studied. And the relationship between the secondary harmonic amplitude and DC current in the excitation current is obtained. The relationship between the secondary harmonic amplitude and DC current is revealed by the linear coefficient X. It is seen from the valve side of the converter transformer that the impedance of AC system side is correlated to the transformer ratio N and linear coefficient X. When the correlated coefficient is(1/N-3/2X),the linear coefficient X and rated excitation current I_(m) of transformer shows negative correlation. The result shows that when the rated excitation current I_(m)<0.089,at this time(1/N-3/2X )< 0,the harmonic instability may likely occur.

关 键 词：谐波 不稳定 铁心饱和 换流变压器 直流输电 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM41