多馈入高压直流输电系统小干扰稳定分析  

Small Signal Stability Analysis of Multi-Infeed HVDC System

作　　者：甄自竞 杜文娟[1] 王海风[1] ZHEN Zijing;DU Wenjuan;WANG Haifeng(Department of Electrical and Electronic Engineering,North China Electric Power University,Beijing 102206,China)

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：《南方电网技术》2018年第11期29-36,共8页Southern Power System Technology

摘　　要：针对多馈入高压直流输电系统的小干扰稳定进行研究,建立了多输入多输出的互联系统模型,将模型划分为两个子系统,分别由LCC-HVDC和系统其他部分构成。研究表明当两个子系统的开环模式靠近时,发生近似强模式谐振,子系统间动态交互作用强烈,其中一个闭环模式处在对应的开环模式右侧导致其阻尼弱化,从而对系统稳定性造成不利影响。为此本文提出开环模式估算方法,根据子系统的开环状态空间方程对闭环模式位置进行估算,并据此提出稳定判断指标和分析步骤对稳定性进行判断。此外,分析了直流落点间连接线的长度对于子系统间交互作用强弱的影响。最后通过算例系统的仿真研究验证了所提方法的准确性。To investigate the small signal stability of multi-infeed HVDC system,a multi-input and multi-output interconnected model with variable speed is established.The model is divided into two separate subsystems which are composed of LCC-HVDC and the rest of the power system.When two open-loop modes of two subsystems are close to each other,a special condition of near strong mode resonance(NESMOR)will take place,and strong dynamic interactions occur between subsystems.Under the NESMOR condition,one of the closed-loop modes is on the right of the corresponding open-loop mode and the damping of the closed-loop mode will be wicker,thus the small signal stability of the system will degrade.A method is proposed to predict the positions of the closed-loop modes based on the open-loop state space equations,also an index and analysis process of evaluating the stability of the system are given.In addition,the impact of the length of the tie-line between the infeeds is studied.Finally,simulation study of example power system is presented to verify the accuracy of the proposed method.

关 键 词：多馈入高压直流输电系统 动态交互 小干扰稳定 近似强模式谐振 

分 类 号：TM721[电气工程—电力系统及自动化]