考虑SVG的光伏电站次同步振荡问题  

Research on Subsynchronous Oscillation of Photovoltaic Power Station Equipped with SVG

作　　者：于永军 张艺[2] 黄碧月 韩应生 孙海顺[2] YU Yongjun;ZHANG Yi;HUANG Biyue;HAN Yingsheng;SUN Haishun(State Grid Xinjiang Electric Power Research Institute,Urumqi 830011,China;State Key Laboratory of Advance Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]国网新疆电力公司电力科学研究院,乌鲁木齐830011 [2]华中科技大学强电磁工程与新技术国家重点实验室,武汉430074

出　　处：《高电压技术》2021年第8期2720-2729,共10页High Voltage Engineering

基　　金：国家电网公司科技项目(SGXJDK00DJJS1800172)。

摘　　要：新能源发电并网系统的振荡问题是电网关注的重要研究课题,揭示振荡发生的机理并明确影响振荡的关键因素是首要研究任务。为此,建立了含静止无功发生器(static var generator,SVG)的光伏并网系统的小信号状态空间模型,通过特征值分析研究了光伏并网系统的主导振荡模式及与其强相关的动态环节,分析了交流侧系统对光伏并网系统振荡特性的影响;采用频率扫描法从电路谐振角度对光伏并网系统次同步振荡(subsynchronous oscillation,SSO)现象进行了解释,并通过时域仿真验证了特征模式分析结果的正确性。研究结果表明:含SVG的光伏并网系统存在一个主导SSO模式,光伏电站并网变流器的控制参数对该模式的稳定性具有重要影响;此外,SVG与光伏发电系统之间也存在相互控制作用,需要合理设计二者的控制参数,以提高系统整体的稳定性。研究内容可为光伏并网系统的运行和控制设计提供指导。The oscillation problem of renewable energy generation connected to power grid system is an important research topic worthy of attention.The primary research task is to reveal the mechanism of oscillation and research the key influencing factors.In this paper,a small-signal mathematical model of photovoltaic(PV)grid-connected system equipped with static var generator(SVG)is built firstly.Then,the characteristic oscillation mode and the dynamic links strongly related to it of PV grid-connected system are studied by eigenvalue analysis,and the influence of AC system on the oscillation characteristics of PV grid-connected system is analyzed.The mechanism of subsynchronous oscillation(SSO)is explained from the point of view of circuit resonance,and the electro-magnetic simulations on the PSCAD/EMTDC is carried out to verify its correctness.The research results indicate that there is a dominant SSO mode in the PV grid-connected system,and the control parameters of the converter have important influences on the stability of this mode.There is a control interaction between SVG and PV,which requires reasonable design of control parameters.The research can provide guidance for the operation and control design of photovoltaic grid-connected systems.

关 键 词：光伏并网系统 弱交流系统 次同步振荡 静止无功发生器 特征值分析 小信号稳定性 

分 类 号：TM712[电气工程—电力系统及自动化] TM615