一种基于逆变器阻抗重塑的新型谐波抑制策略  

A Novel Harmonic Suppression Strategy for Inverters Based on Impedance Reshaping

作　　者：高树新 卞秋野 GAO Shu-xin;BIAN Qiu-ye(State Grid Lijin Power Supply Company,Dongying 257400,China)

机构地区：[1]国网利津县供电公司

出　　处：《电力电子技术》2022年第7期4-7,12,共5页Power Electronics

摘　　要：针对逆变器带非线性负载运行其输出电压含有大量谐波的问题,传统的方法主要是通过无源或有源滤波器来抑制谐波,无疑增加了额外的硬件成本。基于此,通过对逆变器控制环进行改进,提出通过对逆变器输出阻抗进行重塑,进而降低逆变器输出电压畸变率。首先对逆变器输出电压畸变的原因展开详细的分析,在此基础上,提出一种虚拟阻抗的方法,即通过将逆变器输出电流中的谐波分量乘以系数反馈到参考电压中,达到减小逆变器等效谐波输出阻抗的目的,从而逆变器输出侧电压的谐波含量得到有效抑制。其次对虚拟阻抗的选取方法和稳定性进行了分析。最后,通过实验验证了所提控制策略的正确性,结果表明所提控制策略有效降低了输出电压中的各次谐波成分。Aiming at the problem that the output voltage of the inverter with a nonlinear load contains a large number of harmonics,the traditional method is mainly to suppress harmonics by passive or active filters,which undoubtedly adds additional hardware cost.Based on this,through improving the control loop of inverter,the output impedance of inverter is reconstructed to reduce the distortion rate of inverter output voltage.Firstly,a detailed analysis of the causes of inverter output voltage distortion is carried out,based on which a virtual impedance method is proposed.The harmonic components in the inverter output current are fed back to the reference voltage by multiplying the coefficients to achieve the purpose of reducing the equivalent harmonic output impedance of the inverter,so that the harmonic content of the inverter output side voltage is effectively suppressed.Secondly,the selection method and stability of the virtual impedance are analyzed.Finally,the correctness of the proposed control strategy is verified by experimental results,which show that the proposed control strategy effectively reduces each harmonic component in the output voltage.

关 键 词：逆变器 非线性负载 虚拟阻抗 

分 类 号：TM464[电气工程—电器]