电力系统自动化2025，Vol.49Issue(7)：68-79,12.DOI:10.7500/AEPS20231230001
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
摘要
Abstract
The integration of grid-following and grid-forming converters to the power grid brings different influences to the medium-frequency 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 medium-frequency 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 grid-connected 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 medium-frequency band under the grid-following control,and suppresses the system oscillation well.Finally,the correctness of the analysis results is verified by the electromagnetic simulation software.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Key words
grid-following converter/grid-forming converter/medium-frequency oscillation/impedance characteristic/oscillation suppression引用本文复制引用
蒙昌鑫,王延旭,王威儒,刘云飞,董洪达,李成钢..跟网/构网型控制交互下换流器中频特性分析及振荡抑制[J].电力系统自动化,2025,49(7):68-79,12.基金项目
国家电网公司总部科技项目(5100-202399363A-2-2-ZB). This work is supported by State Grid Corporation of China(No.5100-202399363A-2-2-ZB). （5100-202399363A-2-2-ZB）
