风电-柔直系统次同步振荡的耦合阻抗模型分析  

Impedance Coupling Model based Sub-Synchronous Oscillation Analysis of Wind Farms Connected to VSC-HVDC Transmission System

作　　者：张帆 尹聪琦 袁豪 洪潮 杨雄平[3] 谢小荣[2] ZHANG Fan;YIN Congqi;YUAN Hao;HONG Chao;YANG Xiongping;XIE Xiaorong(State Key Laboratory of HVDC,Electric Power Research Institute,CSG,Guangzhou 510663,China;State Key Lab of Power Systems,Dept.of Electrical Engineering,Tsinghua University,Beijing 100084,China;China Southern Power Grid Co.,Ltd.,Guangzhou 510663,China)

机构地区：[1]直流输电技术国家重点实验室(南方电网科学研究院),广州510663 [2]电力系统及发电设备控制与仿真国家重点实验室(清华大学电机系),北京100084 [3]中国南方电网有限责任公司,广州510663

出　　处：《南方电网技术》2022年第3期24-31,共8页Southern Power System Technology

基　　金：国家自然科学基金重点项目(51737007)。

摘　　要：大规模风电接入柔性直流换流站会引入一种危及交流系统稳定的新型次同步振荡,它是电力电子控制通过交流电网相互作用的结果,这种相互作用在次同步频率及其互补超同步频率之间存在较强的频率耦合效应,导致采用常规的一维阻抗模型难以进行准确分析。考虑该频率耦合效应,采用耦合阻抗模型并基于聚合阻抗频率特性来分析风电-柔直次同步振荡的发生条件,研究风电机组台数、交流线路长度、风电机组出力水平及柔直变流器控制器参数等对振荡稳定性的影响;时域仿真验证了耦合阻抗模型及其分析结果的有效性。Large-scaled wind-farm connected to VSC-HVDC transmission system(WF-VSC system)may induce a new type of sub-synchronous oscillation which threatens the stability of the AC grid,this type of oscillation is the results of the interactive behaviours among the power electronic controllers through the AC grid,the interactive behaviours cause the impedance coupling characteristics of the WF-VSC system from sub-synchronous frequency range to twice fundamental frequency range,leading to significant inaccuracy when analyzing the impedance coupling characteristic using one-dimension impedance model.In this paper,the coupling characteristic is taken into account,and the sub-synchronous oscillation conditions of the WF-VSC are elaborated based on the coupled impedance model and the freuqency response characteristics of the integrated impedance,and the impacts of the oscillation conditions,such as the number of the wind turbines,the length of the AC transmission line,the output power ratio of the wind turbines,and the parameters of the VSC controllers,on the sub-synchronous oscillations stability are also analyzed.The simulation results verity the the effectiveness of the coupled impedance model and the analysing results.

关 键 词：阻抗模型 振荡 风电 柔性直流输电 

分 类 号：TM721.1[电气工程—电力系统及自动化]