跟网/构网型控制交互下换流器中频特性分析及振荡抑制  

Medium-frequency Characteristic Analysis and Oscillation Suppression of Converter with Interaction Between Grid-following and Grid-forming Control

作　　者：蒙昌鑫 王延旭 王威儒 刘云飞 董洪达 李成钢 MENG Changxin;WANG Yanxu;WANG Weiru;LIU Yunfei;DONG Hongda;LI Chenggang(School of Electrical Engineering,Northeast Electric Power University,Jilin 132012,China;Electric Power Research Institute of State Grid Jilin Electric Power Co.,Ltd.,Changchun 130021,China)

机构地区：[1]东北电力大学电气工程学院,吉林省吉林市132012 [2]国网吉林省电力有限公司电力科学研究院,吉林省长春市130021

出　　处：《电力系统自动化》2025年第7期68-79,共12页Automation of Electric Power Systems

基　　金：国家电网公司总部科技项目(5100-202399363A-2-2-ZB)。

摘　　要：跟网/构网型换流器接入电网时会对系统中频段稳定性产生不同的影响,为剖析二者在该频段下的差异,首先,采用谐波线性化方法建立跟网/构网型换流器小信号序阻抗模型,对比跟网/构网型换流器中频段的序阻抗特性。基于序阻抗模型详细分析了滤波电感、跟网型换流器电流内环和锁相环、构网型换流器有功阻尼系数和虚拟转动惯量系数对换流器中频段阻抗特性的影响,并利用阻抗灵敏度分析法得出中频段的主导因素。利用叠加定理探究交互阻抗对换流器联合阻抗特性的影响,推导出跟网/构网型换流器并网系统组成的三端口网络稳定性判据,总结系统参数及输出功率对二者联合阻抗的影响规律。此外,从联合阻抗的角度出发,进一步探究2种换流器的不同功率渗透率对系统稳定性的影响,构网型换流器的正电阻特性能够削弱由跟网型换流器控制环节引入的负阻尼特性,从而使跟网型换流器从负电阻及容性过渡到正电阻及感性,进而改善跟网控制下中频段振荡稳定性,对系统振荡起到良好的抑制作用。最后,利用电磁仿真软件验证了分析结果的正确性。The integration of grid-following and grid-forming converters to the power grid brings different influences to the mediumfrequency stability of the system.To analyze the differences between the two influences in the medium-frequency band,this paper first establishes the small-signal sequence impedance models of grid-following and grid-forming converters based on the harmonic linearization method.The sequence impedance characteristics in the medium-frequency band of the grid-following and grid-forming converters are compared.Based on the sequence impedance model,the influence of the filter inductance of the converter,the current inner loop and the phase-locked loop of the grid-following converter,and the active power damping coefficient and the virtual rotational inertia coefficient of the grid-forming converter on the impedance characteristics of the converters in the mediumfrequency band is analyzed in detail.The dominant factors affecting the medium-frequency band are obtained by using the impedance sensitivity analysis method.Then,the influence of the interaction impedance on the joint impedance characteristics of the converter is analyzed by using the superposition theorem.The stability criterion of the three-port network composed of the gridconnected system with grid-following and grid-forming converters is derived.The influence of the system parameters and the output power on the joint impedance of grid-following and grid-forming converters is analyzed.In addition,from the perspective of joint impedance,the influence of different power proportions of the two types of converters on the system stability is further explored.The positive resistance characteristic of the grid-forming converter can mitigate the negative damping characteristic introduced by the control link of the grid-following converter,so that the grid-following converter can transition from negative resistance and capacitance to positive resistance and inductance,which enhances the stability of the oscillation in the mediumfrequency band under

关 键 词：跟网型换流器 构网型换流器 中频振荡 阻抗特性 振荡抑制 

分 类 号：TM721[电气工程—电力系统及自动化]