三电平逆变器中点电位偏移机理分析与平衡方法研究  

Analysis of Neutral-point Potential Shift Mechanism and Balance Method for Three-level Inverter

作　　者：耿后来[1] 高宁 吴卫民[2] GENG Houlai;GAO Ning;WU Weimin(Sungrow Power Supply Co.,Ltd.,Hefei 230088,China;Department of Electrical Engineering,Shanghai Maritime University,Shanghai 201306,China)

机构地区：[1]阳光电源股份有限公司,合肥230088 [2]上海海事大学电气工程系,上海201306

出　　处：《电源学报》2024年第S01期50-58,共9页Journal of Power Supply

基　　金：国家自然科学基金面上资助项目(51877130)。

摘　　要：针对三电平中点钳位逆变器的中点电位平衡控制问题,分析T型三电平逆变器的中点波动原因,基于无谐波注入和动态谐波注入方式对中点电流三次谐波的周期傅里叶级数进行推导分析。首先推导出一种开环的谐波注入算法,在此基础上提出一种基于比例谐振控制器的闭环谐波注入算法进行中点电流抑制。采用MATLAB/Simulink仿真软件对开环谐波注入和闭环谐波注入的算法进行了仿真,搭建了40 kW的三电平逆变器进行了实验验证。仿真和实验结果均可验证理论分析的正确性及所提控制策略的有效性。Aimed at the problem of neutral-point potential balance control of three-level neutral-point clamped inverters,the cause of neutral-point fluctuation of a T-type three-level inverter was analyzed.Based on the non-harmonic injection and dynamic harmonic injection methods,the period Fourier series of the third-order harmonic of neutral-point current was derived and analyzed.First,an open-loop harmonic injection algorithm was derived,and a closed-loop harmonic injection algorithm based on proportional-resonance controller was proposed accordingly to suppress the neural-point current.Then,MATLAB/Simulink simulation software was used to simulate the open-loop harmonic injection and closed-loop harmonic injection algorithms,and a 40 kW three-level inverter was built for experimental verification.Both the simulation and experimental results can verify the correctness of theoretical analysis and the effectiveness of the proposed control strategy.

关 键 词：三电平逆变器 中点电位 比例谐振控制 

分 类 号：TM464[电气工程—电器]