并联感应电动机聚合负荷引起含双馈风电场电力系统振荡研究  

Research on Oscillations of the Power System Integrated With the DFIG-based Wind Farm as Caused by the Aggregated Load of Induction Motors in Parallel Connection

作　　者：苏国贇 杜文娟 王海风 SU Guoyun;DU Wenjuan;WANG Haifeng(State Grid Economic and Technological Research Institute Co.,Ltd.,Changping District,Beijing 102209,China;College of Electrical Engineering,Sichuan University,Chengdu 610065,Sichuan Province,China)

机构地区：[1]国网经济技术研究院有限公司,北京市昌平区102209 [2]四川大学电气工程学院,四川省成都市610065

出　　处：《中国电机工程学报》2021年第6期2125-2135,共11页Proceedings of the CSEE

摘　　要：围绕并联感应电动机聚合负荷,研究了该负荷自身的稳定性特征及其与双馈感应风电机组(doubly-fed induction generator,DFIG)间交互作用对电力系统稳定性的影响。首先,建立了聚合负荷线性化状态空间模型;理论研究表明,当聚合负荷内部n台感应电动机同型时,聚合负荷可等值变换为n个独立的等值子系统,其中1个等值子系统的感应电动机振荡模式(induction motor oscillation mode,IMOM)将随着电动机数量n的增加在复平面上不断移动,甚至可能穿越虚轴进入右半平面;并提出一种预估该移动的振荡模式负阻尼时对应的电动机数量的方法。其次,构建了由聚合负荷开环子系统和电力系统其余部分开环子系统构成的闭环互联系统模型,并从开环模式耦合的角度阐述了聚合负荷与双馈风机间交互作用导致电力系统振荡的机理:当开环感应电动机振荡模式与开环风机振荡模式在复平面上靠近时,可能出现的开环模式耦合将引发2个子系统间的强交互作用,并导致闭环系统振荡模式阻尼减弱。最后,通过新英格兰系统对理论分析及结论进行了验证。This paper mainly investigated the stability of the aggregated load of induction motors in parallel connection(abbreviation: the aggregate load) and the impact of dynamic interaction between the aggregate load and the doubly-fed induction generator(DFIG)–based wind farm on power system dynamic stability. Firstly, a linearized state space model of the aggregated load was established. It is theoretically analyzed that when the n internal motors of the aggregated load are in the same type, the aggregate load can be divided into n independent equivalent subsystems. And an induction motor oscillation mode(IMOM) of one of the equivalent subsystems may move towards the right on the complex plane with the increase of the number of motors n. Besides, a prediction index was proposed to predicate the number of internal motors when the moving IMOM becomes negative damping. Then, based on a closed-loop interconnected system model which contains an open-loop aggregated load subsystem and an open-loop DFIG subsystem, the mechanism of power system oscillation was revealed from the perspective of open-loop modal coupling. When an open-loop IMOM and an open-loop DFIG oscillation mode approach to each other on the complex plane, the dynamic interaction between the two open-loop subsystems becomes strong, which will degrade the damping of the corresponding closed-loop oscillation mode. Finally, the theoretical analysis and obtained conclusions were demonstrated and validated by the New England system.

关 键 词：并联感应电动机聚合负荷 双馈风机(DFIG) 感应电动机振荡模式(IMOM) 开环模式耦合 电力系统振荡 

分 类 号：TM712[电气工程—电力系统及自动化]