直流电抗器对VSC-MTDC输电系统稳定性的影响分析  

Impact of DC Reactors on Stability of VSC-MTDC Transmission System

作　　者：李慧[1] 罗奇 张柏林 范新桥[1] LI Hui;LUO Qi;ZHANG Bolin;FAN Xinqiao(School of Automation, Beijing Information Science & Technology University, Haidian District, Beijing 100192, China;Shenzhen Zhenhua Microelectronics Co., Ltd., Shenzhen 518000, Guangdong Province, China;State Grid Gansu Electric Power Corp., Lanzhou 730000, Gansu Province, China)

机构地区：[1]北京信息科技大学自动化学院,北京市海淀区100192 [2]深圳市振华微电子有限公司,广东省深圳市518000 [3]国网甘肃省电力公司,甘肃省兰州市730000

出　　处：《电网技术》2019年第7期2641-2648,共8页Power System Technology

基　　金：北京市自然科学基金项目(3172015)~~

摘　　要：直流电抗器可以限制多端柔性直流输电系统中直流故障电流的上升率,但大容量的直流电抗器又会对系统稳定性产生一定的影响。提出了含有直流电抗器的多端柔性直流输电系统稳定性模型,推导出含交流侧参数、换流站参数以及带直流电抗器的输电线路分布参数的多输入–多输出状态空间矩阵表达式,绘制出不同直流电抗器情况下系统的根轨迹曲线,分析了主导极点的变化情况,确定了不同接收功率下保证系统稳定运行的直流电抗器临界值,为直流电抗器参数的选取提供了理论依据。利用PSCAD/EMTDC软件搭建了三端柔性直流输电系统模型,验证了该理论方法的正确性。DC reactors can limit rise rate of DC fault current in multi-terminal flexible DC transmission system, but large capacity DC reactors have significant impact on stability of the system. In this paper, a small-signal model of a multi-terminal flexible DC transmission system with DC reactors is proposed and the state-space matrix expression with multi-input and multi-output variables is deduced, including parameters of AC side and converter station and distributed parameters of DC line with DC reactors. The root-locus curves for different DC reactors are drawn, and the critical values of DC reactors under different received powers are determined by analyzing the changes of dominant poles, providing theoretical basis for selecting DC reactor parameters. A three-terminal flexible DC transmission system is established in PSCAD/EMTDC, verifying correctness of the proposed method.

关 键 词：多端柔性直流输电 直流电抗器 稳定性分析 小信号法 

分 类 号：TM721[电气工程—电力系统及自动化]