限流电抗器对接入弱交流电网的VSC-HVDC系统的小信号稳定性影响分析  

Impact Analysis of Current Limiting Reactor on Small Signal Stability of VSC-HVDC Systems Connected to the Weak AC Power Grid

作　　者：杨佳艺[1] 赵成勇[1] 苑宾[1] 

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《华北电力大学学报（自然科学版）》2017年第1期9-15,共7页Journal of North China Electric Power University：Natural Science Edition

基　　金：国家高技术研究发展计划(863计划)资助项目(2013AA050105)

摘　　要：小信号稳定性分析对于控制器的设计及柔性直流输电系统工程的建设具有重要作用,直流侧限流电抗器对柔性直流输电系统的小信号稳定性会产生一定的影响。首先建立了接入弱交流电网的VSC系统的小信号模型,推导了VSC系统状态空间的矩阵表达式,并绘制出了不同限流电抗器时系统的根轨迹曲线,研究了主导极点在坐标系中的变化情况。研究结果表明:弱交流电网下,VSC系统的小信号稳定性随着限流电抗器的增大而降低直至失稳。最后,在PSCAD/EMTDC环境中搭建了VSC系统的仿真模型,仿真结果验证了小信号模型的正确性,同时证明了VSC系统的小信号稳定性随限流电抗器的增大而降低这一结论。Small signal stability analysis plays an important role in designing controllers and constructing the voltage source converter based high-voltage direct current（VSC-HVDC） systems. Current limiting reactor at the DC side can affect the small signal stability of VSC-HVDC systems. Firstly,the small signal model of VSC system connected to the weak AC power grid is built,and the matrix expression of state space model of the VSC system is derived in this paper.Then,root-locus curves of different numerical current limiting reactors are drawn,also,how dominant poles change in the coordinate system is obtained. The results show that the small signal stability of VSC-HVDC decreases as current limiting reactor increases in the weak AC power grid. At last,a VSC simulation model is built in PSCAD/EMTDC. The results indicate the correctness and validity of the small signal model,also,the conclusion that small signal stability decreases with increasing current limiting reactor is proved again.

关 键 词：弱交流电网 柔性直流输电 限流电抗器 小信号稳定性分析 状态空间方程 

分 类 号：TM726[电气工程—电力系统及自动化]