摘要
可再生能源如风电、光伏等,须经电能逆变环节产生稳定交流电压连接用户负载或接入电网。逆变器作为可再生能源电能变换系统的核心设备,应满足高效、高功率密度、电压增益宽范围可调等应用需求。传统H桥逆变器输出交流电压总谐波失真(total harmonic distortion,THD)高且无升压能力。近年来开关电容多电平逆变器(switched-capacitor multi-level inverter,SCMLI)受到广泛关注,该类变换器具有高增益、自均压、器件电压应力低、输出电压谐波含量少等优点。但现有SCMLI电压调制能力弱、输入脉冲电流峰值高、电压增益可调范围窄,因此文中提出一种新型准Z源单相SCMLI,具有输入电压宽范围可调、输入电流连续且无脉冲、可拓展等特点。与现有拓扑相比,文中拓扑所需器件数量较少,电压应力较小,且支持更宽输入电压范围。文中首先介绍该拓扑工作原理及参数设计方法,然后确定原型机系统参数,最后通过仿真和实验验证理论分析的正确性。相关研究结果表明文中拓扑可在较宽输入电压范围输出高质量七电平交流电,THD为23.8%,远低于传统二电平逆变器,可有效提高波形质量,减小输出滤波器体积。
Renewable energy such as wind power,photovoltaics require power inversion to generate stable AC voltage forconnection to loads or the grid.As a core device in renewable energy power conversion systems,inverters are required to meetthe application demands of high efficiency,high power density,and wide-range adjustable voltage gain.Traditional H-bridgeinverter suffers from a high total harmonic distortion(THD)of the output AC voltage and no boosting capability.Recently theswitched-capacitor multi-level inverter(SCMLI)excels in applications like renewable energy due to its high gain,self-balancing capabilities,low device voltage stress,and minimal output voltage harmonics.However existing SCMLIs are limitedby their weak voltage modulation and high peak input pulse current.A novel quasi-Z-source single-phase SCMLI is proposedin this paper,offering a wide adjustable input voltage range,continuous and pulse-free input current,and scalability.Comparedto similar topologies,the proposed topology requires fewer components and lower voltage stress,enabling direct conduction ofthe power switches in the output bridge arm of the quasi-Z-source circuit and supporting a wider input voltage range.Firstly,the working principle and parameter design method of the proposed topology are introduced.Based on this,the prototypesystem parameters are determined,and the correctness of the theoretical analysis is verified through simulation andexperiments.The results indicate that the proposed topology can output high-quality seven-level AC with a wide input voltagerange.The THD is as low as 23.8%,significantly lower than that of traditional two-level inverters,effectively improving theoutput power quality and reducing the size of the output filter.
作者
李群
李强
汪成根
邹小明
LI Qun;LI Qiang;WANG Chenggen;ZOU Xiaoming(State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China)
出处
《电力工程技术》
北大核心
2026年第2期1-10,共10页
Electric Power Engineering Technology
基金
国家电网有限公司总部科技项目“含多构网型变流器的中远海风电场经柔直并网主动频率支撑关键技术”(5108-202218280A-2-241-XG)。
