单相光伏级联多电平逆变器漏电流抑制与功率均衡控制综述  

Review on Leakage Current Suppression and Power Balance Control of Single-phase Photovoltaic Cascaded Multilevel Inverter

作　　者：张兴[1] 吴孟泽 王明达 王平洲 付新鑫 赵涛 ZHANG Xing;WU Mengze;WANG Mingda;WANG Pingzhou;FU Xinxin;ZHAO Tao(National and Local Joint Engineering Laboratory for Renewable Energy Access to Grid Technology(Hefei University of Technology),Hefei 230009,China;College of Electrical Engineering,Qingdao University,Qingdao 266071,China)

机构地区：[1]可再生能源接入电网技术国家地方联合工程实验室(合肥工业大学),安徽省合肥市230009 [2]青岛大学电气工程学院,山东省青岛市266071

出　　处：《电力系统自动化》2023年第9期202-215,共14页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51937003)。

摘　　要：单相级联多电平逆变器(CMI)因其可实现组件级最大功率点跟踪(MPPT)、组件可关断、多电平输出电压谐波含量低、集优化器与并网逆变器为一体的结构等优势,近年来在光伏并网系统的研究领域受到关注。以单相非隔离型独立直流母线结构的光伏级联多电平逆变器(PV-CMI)为研究对象,针对其存在的两个问题进行综述:一是因缺少隔离环节可能导致的漏电流问题:二是单相PV-CMI各单元间相互独立的直流光伏输入可能导致的功率不均衡问题。这两个问题对单相PVCMI的安全稳定运行造成了威胁,从而极大地限制了单相PV-CMI的推广和应用。文中分析了单相PV-CMI的基本原理和拓扑特点,分别就其漏电流与光伏功率不均衡两大关键问题,综述现有的研究方案并进行了总结。最后,展望了PV-CMI未来的发展趋势及其存在的技术挑战,为后续研究提供了参考。The single-phase cascaded multilevel inverter(CMI)has attracted much attention in the research field of grid-connected photovoltaic systems in recent years because of its advantages such as the module-level maximum power point tracking(MPPT),the module-level shutdown,the low harmonic content of multilevel output voltage and the structure integrating the optimizer and the grid-connected inverter.The single-phase transformerless photovoltaic cascaded multilevel inverter(PV-CMI)with the independent DC bus structure is taken as the research subject,and two existing problems are summarized.One is that the lack of isolation circuits may lead to leakage current problems,and the other is that the independent DC photovoltaic inputs between the units in single-phase PV-CMI may lead to power imbalance problems.These two problems threaten the safe and stable operation of the single-phase PV-CMI,thus greatly limiting the promotion and application of the single-phase PV-CMI.The basic principle and topology characteristics of the single-phase PV-CMI are analyzed,and the existing research schemes are summarized on the two key problems of its leakage current and photovoltaic power imbalance.Finally,the current technical challenges and the future development trends of the PV-CMI are presented,which provides references for the subsequent research.

关 键 词：级联多电平逆变器(CMI) 漏电流 功率不均衡 光伏逆变器 

分 类 号：TM464[电气工程—电器]