计及SVG的双馈风电场高频阻抗建模及振荡分析  

High Frequency Impedance Modeling and Oscillation Analysis of DFIG-based Station Considering SVG

作　　者：熊小玲 罗博晨 刘京波[2] 张扬帆[2] 吴宇辉[2] 郭春义 XIONG Xiaoling;LUO Bochen;LIU Jingbo;ZHANG Yangfan;WU Yuhui;GUO Chunyi(State Key Laboratory for Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China;North China Electric Power Research Institute Co.,Ltd.(State Grid Jibei Electric Power Co.,Ltd.Research Institute),Haidian District,Beijing 100045,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206 [2]华北电力科学研究院有限责任公司(国网冀北电力有限公司电力科学研究院),北京市海淀区100045

出　　处：《电网技术》2023年第7期2905-2915,共11页Power System Technology

摘　　要：接入静止无功发生器(static var generator,SVG)的双馈风电机组(doubly-fed induction generator,DFIG),由于它们的交互作用,易产生高频振荡现象,极大地威胁到了双馈风电场的安全稳定运行。针对这一问题,分别建立了SVG、双馈风力发电机组和电缆线路的高频阻抗模型,并通过MATLAB/Simulink仿真平台进行频率扫描,验证了阻抗模型的正确性。经分析发现双馈机组与电缆连接后高频阻抗呈现容性,SVG高频阻抗呈现负电阻电感特性,因此双馈风电场接入SVG后会引发高频谐振现象,导致高频振荡失稳。同时,基于高频阻抗模型研究了接入SVG后影响互联系统高频稳定性的关键因素,发现SVG和DFIG网侧换流器的延时环节、电流环的比例系数是引发风电场高频振荡的主要原因。针对振荡原因,进一步提出了一种基于同步旋转坐标系下电压前馈的SVG阻抗重塑策略,提高了风电场高频稳定性。最后,在MATLAB/Simulink中建立了双馈风电场的电磁暂态仿真模型,结合实际案例参数,验证了理论分析的正确性和阻抗重塑方法的有效性。Doubly-fed induction generators(DFIG)connected to the static var generator(SVG)is prone to high-frequency oscillation due to their interactions,which greatly threatens the stable operation of the doubly fed wind farm.To solve this problem,this paper establishes the high-frequency impedance models for the SVG,the DFIG and the cables respectively.The theoretical impedance model is verified by frequency scanning through the MATLAB/Simulink simulation platform.Through analysis,it is found that after the DFIG is connected with the cables,the high-frequency impedance becomes capacitive,and the high frequency impedance of the SVG shows the characteristic of negative resistance and inductance.Therefore,after the doubly-fed wind farm is connected to the SVG,the high frequency resonance peak occurs,causing high frequency oscillation instability.At the same time,based on the high frequency impedance model,the key factors affecting the high frequency stability of the system after connecting the SVG are studied.It is found that the delay and the proportional gain of the current loop of the SVG and the DFIG grid side converter are the main factors for the high frequency oscillation of the wind farm.Aiming at the cause of oscillation,this paper further proposes a SVG impedance reshaping method based on the voltage feedforward in the synchronous rotating frame in order to improve the stability of the wind farm.Finally,the electromagnetic transient simulation model of the doubly-fed wind farm is established in the MATLAB/Simulink.With the parameters of actual cases the correctness of theoretical analysis and the effectiveness of proposed method is verified.

关 键 词：静止无功发生器 双馈风机 小信号稳定性 高频振荡 阻抗重塑 

分 类 号：TM721[电气工程—电力系统及自动化]