基于三频段阻抗重塑的LCL型并网变流器谐振抑制策略  

Resonance Suppression Strategy for LCL⁃Type Grid⁃Connected Converter Based on Three⁃Frequency⁃Band Impedance Remodeling

作　　者：冯豪哲 夏向阳[1] 刘俊翔 陈贵全 赵晓悦 FENG Haozhe;XIA Xiangyang;LIU Junxiang;CHEN Guiquan;ZHAO Xiaoyue(College of Electrical and Information Engineering,Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学电气与信息工程学院,湖南长沙410114

出　　处：《湖南电力》2024年第6期67-75,共9页Hunan Electric Power

基　　金：国家自然科学基金项目(51977014);湖南省教育厅科学研究重点项目(22A0230)。

摘　　要：弱电网下采用电压前馈控制会增大并网变流器输出阻抗在交截频率处的负相移,可能导致并网电流的谐波谐振。针对这一问题,提出一种基于三频段阻抗重塑的LCL型并网变流器谐振抑制策略。该策略在电网电压前馈控制的基础上建立输出阻抗的三频段等效模型,利用三频段重塑增益因子重塑并网变流器不同频段的输出阻抗,减少输出阻抗在中频段的负相移,提高并网变流器在弱电网下的稳定运行能力。仿真结果表明,该策略保留了传统电压前馈控制对电网背景谐波的抑制能力,提高了并网系统的相位裕度,有效抑制了并网电流的谐振现象。The use of voltage feed⁃forward control under a weak grid will increase the negative phase shift of the output impedance of the grid⁃connected converter at the cross⁃cutting frequency,which may lead to the harmonic resonance of the grid⁃connected current.Aiming at the problem a resonance suppression strategy for the LCL⁃type grid⁃connected converter based on the three⁃frequency⁃band impedance remodeling is proposed.The strategy establishes a three⁃frequency⁃band equivalent model of output impedance on the basis of grid voltage feed⁃forward control,and uses the three⁃frequency band reshaping gain factor to reshape the output impedance of the grid⁃connected converter in different frequency bands,which reduces the negative phase shift of the output impedance in the mid⁃frequency band,and improves the stable operation capability of the grid⁃connected converter under a weak power grid.Simulation results show that the strategy retains the ability of traditional voltage feed⁃forward control to suppress grid background harmonics,improves the phase margin of the grid⁃connected system,and effectively suppresses the resonance phenomenon of the grid⁃connected current.

关 键 词：弱电网 LCL并网变流器 背景谐波电压 三频段阻抗重塑 电网电压前馈 

分 类 号：TM46[电气工程—电器]