构网型控制改善跟网型变流器次/超同步振荡稳定性的机理和特性分析  

Mechanism and Characteristics of Grid-forming Control for Improving Sub/Super Synchronous Oscillation Stability of Grid-following-based Grid-connected Converter

作　　者：刘朋印 谢小荣[1] 李原 易善军 苏鹏 戴幸涛 马宁宁 LIU Pengyin;XIE Xiaorong;LI Yuan;YI Shanjun;SU Peng;DAI Xingtao;MA Ningning(State Key Laboratory of Power System Operation and Control(Department of Electrical Engineering,Tsinghua University),Haidian District,Beijing 100084,China;State Grid East Inner Mongolia Electric Power Co.,Ltd.,Hohhot 010010,Inner Mongolia Autonomous Region,China)

机构地区：[1]新型电力系统运行与控制全国重点实验室(清华大学电机系),北京市海淀区100084 [2]国网内蒙古东部电力有限公司,内蒙古自治区呼和浩特市010010

出　　处：《电网技术》2024年第3期990-997,共8页Power System Technology

基　　金：国家自然科学基金项目(U22B20100,51925701);国网内蒙古东部电力有限公司科技项目(SGMD0000DDJS2250017)。

摘　　要：构网型(grid-forming,GFM)并网变流器具有良好的弱电网稳定性,同时能够改善跟网型变流器的次/超同步振荡稳定性。为明确GFM控制改善振荡稳定性的机理和特性,首先推导了GFM变流器电路特性与每个控制环节的关系,并分别从变流器自身电路特性、变流器并网系统整体阻抗特性角度揭示了GFM控制改善振荡稳定性的电路机理。然后,基于阻抗模型定量分析了GFM变流器占比提升对系统振荡频率、阻尼的影响。最后,利用电磁暂态仿真进行了验证。结果表明:GFM变流器在无功控制环节、电压外环作用下表现为“正电阻”,能够削弱跟网型变流器控制环节引入的负阻尼特性,进而改善系统次/超同步振荡稳定性;此外,GFM变流器占比提升能够显著改善系统振荡阻尼,但对振荡频率影响较小。The grid-forming(GFM)-based grid-connected converter(GCC)is known to perform a great sub/super synchronous oscillation stability in weak AC grids and may also improve the oscillation stability of the grid-following(GFL)-based GCC.This paper aims to reveal the mechanism and characteristics of the GFM control for improving the oscillation stability.Firstly,this paper theoretically derived the relationships between the circuit characteristics and each of the control loops of the GFM-based GCC.The circuit characteristics of the GFM-based GCC and the impedance characteristics of a wind farm are analyzed to reveal the mechanism for improving the oscillation stability.Then,this work quantitatively assessed the influence of the increasing GFM-based GCC on the oscillation frequency and damping.Finally,the mechanism and characteristics are validated by the electromagnetic transient simulations.The results reveal that the GFM-based GCC exhibits a positive resistance and reactance,which may diminish the negative resistance and capacitance introduced by the GFL-based GCC and subsequently improve the oscillation stability.Additionally,as the penetration of the GFM-based GCC increases,the oscillation damping will be significantly improved while the oscillation frequency changes slightly.

关 键 词：构网控制 并网变流器 次/超同步振荡 电路特性 弱电网 

分 类 号：TM721[电气工程—电力系统及自动化]