弱电网下构网型LCL逆变器谐波电流抑制研究  

Harmonic current suppression of a grid-forming LCL inverter in a weak grid

作　　者：夏烈 陈志磊 杨青斌 张侃健[1] 沈思恒 XIA Lie;CHEN Zhilei;YANG Qingbin;ZHANG Kanjian;SHEN Siheng(School of Automation,Southeast University,Nanjing 210018,China;China Electric Power Research Institute,Beijing 100192,China)

机构地区：[1]东南大学自动化学院,江苏南京210018 [2]中国电力科学研究院有限公司,北京100192

出　　处：《电力系统保护与控制》2025年第3期130-139,共10页Power System Protection and Control

基　　金：国家电网有限公司科技项目“计及受端电网强度变化的光储电站协同支撑技术研究与应用”资助(5442NY 230055)。

摘　　要：针对弱电网下构网型LCL三相四线逆变器网侧电流的畸变问题,提出了一种基于相位补偿-多谐振控制器(phase compensated multi-resonant controller,PCMRC)电压前馈的谐波电流抑制方法。首先,从构网型LCL逆变器输出阻抗的角度出发,建立了弱电网下构网型LCL逆变器阻抗模型。在此基础上,分析了当采用传统单电压前馈方法时,系统在电网谐波频率处存在输出阻抗较低、谐波电流抑制能力较弱的不足。进一步地,考虑LCL滤波器有源阻尼环路的影响,在传统单电压前馈的基础上,引入了PCMRC电压前馈方式,利用阻抗波德图分析了所提方法的谐波抑制性能。并且详细设计了PCMRC的主要参数,分析了系统的输出阻抗和谐波抑制能力。最后,搭建了实验平台,实验结果表明所提方法能够有效提高电网谐波频率处的逆变器阻抗,从而抑制由电网谐波引起的电流畸变。并且在电网阻抗变化时,系统均能保持很好的稳定性。To solve the current distortion problem of a grid-forming LCL three-phase four-wire inverter in a weak grid,a harmonic current suppression method based on a phase-compensated multi-resonant controller(PCMRC)feedforward voltage is proposed.First,looking at the output impedance of the grid-forming LCL inverter,an impedance model of the inverter in a weak grid is established.When the traditional unit feedforward voltage is adopted,the shortcomings of the system low output impedance gain and weak harmonic current suppression ability at the harmonic frequency of the grid is analyzed.Then,considering the influence of the active damping loop of the LCL filter,and based on the traditional unit feedforward voltage,the PCMRC feedforward voltage is introduced.The harmonic suppression performance of the proposed method is analyzed by an impedance bode diagram.The main parameters of PCMRC are designed in detail,and the system output impedance and harmonic suppression ability are analyzed.Finally,an experimental platform is established,and the results show that the proposed method can improve the impedance of the inverter at the harmonic frequency of the grid effectively.Therefore the current distortion caused by harmonics of the grid is suppressed,and the system can maintain good stability when the impedance of the grid changes.

关 键 词：弱电网 电网谐波 谐波电流抑制 相位补偿 多谐振控制器 

分 类 号：TM464[电气工程—电器]