Grid Synchronization Control for Grid-connected Voltage Source Converters Based on Voltage Dynamics of DC-link Capacitor  

作　　者：Chunyi Han Lei Shang Shi Su Xuzhu Dong Bo Wang Hao Bai Wei Li 

机构地区：[1]Hubei Engineering and Technology Research Center for AC/DC Intelligent Distri bution Network,School of Electrical Engineering and Automation,Wuhan Uni versity,Wuhan 430072,China [2]the Electric Power Research Institute,Yunnan Power Gird Co.,Ltd.,Kunming 650217,China [3]China Southern Power Grid Electric Power Research Institute,China Southern Power Grid Co.,Ltd.,Guangzhou 510000,China

出　　处：《Journal of Modern Power Systems and Clean Energy》2024年第5期1678-1689,共12页现代电力系统与清洁能源学报（英文）

基　　金：supported by Science and Technology Project of Yunnan Power Grid Co.,Ltd.(No.YNKJXM20222105)。

摘　　要：This paper proposes a grid synchronization control strategy for the grid-connected voltage source converters(VSCs)based on the voltage dynamics of the DC-link capacitor in the VSC.The voltage dynamics of the DC-link capacitor are used to regulate the frequency and phase angle of the inner potential of the VSC,synchronizing the VSC with grid.Firstly,in the proposed strategy,the active power regulation and grid synchronization of the VSC are combined,which are separated in the traditional control strategy.This can avoid the instability of the VSC in a weak grid with a low short circuit ratio(SCR),aroused by the dynamic interaction between the separated control loops in traditional control strategies.Secondly,the energy stored in the DC-link capacitor is directly coupled with the grid via the inner potential of the VSC,and the inertia characteristic is naturally featured in the inner potential by the proposed strategy.With the increase of the capacitance,the natural inertial response of the VSC is helpful to improve the grid frequency dynamic.Finally,simulation results are presented to validate the correctness and effectiveness of the proposed strategy in the enhancement of the grid frequency and voltage dynamic support capability.

关 键 词：DC-link voltage dynamics grid synchronization control grid frequency and voltage dynamic support small-signal stability weak grid 

分 类 号：TM73[电气工程—电力系统及自动化] TM46[自动化与计算机技术—检测技术与自动化装置] TP273[自动化与计算机技术—控制科学与工程]