非隔离型级联双降压并网逆变器及其漏电流抑制  

Analysis of Non-isolated Cascaded Dual-buck Grid-connected Inverter and Its Leakage Current Suppression

作　　者：代云中[1] 张荣飞 谢开汶 王宇洁 何俊杰 DAI Yunzhong;ZHANG Rongfei;XIE Kaiwen;WANG Yujie;HE Junjie(School of Electrical Engineering,Southwest Petroleum University,Chengdu 610500,China;College of Electrical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]西南石油大学电气信息学院,成都610500 [2]四川大学电气工程学院,成都610065

出　　处：《高电压技术》2020年第7期2434-2443,共10页High Voltage Engineering

基　　金：国家重点研发计划(2016YFF0203400);国家自然科学基金(61703354)。

摘　　要：为了抑制传统双降压式并网逆变器的漏电流,提出了一种非隔离型级联双降压式并网逆变器(non-isolated cascadeddual-buckgrid-connectedinverter,CDBGCI)及单极性双载波正弦脉宽调制(dual-carriersinusoidalpulse widthmodulation,DCSPWM)策略。采用共模等效电路法分别建立了CDBGCI的高频和低频共模等效模型,并详细分析了逆变器的高频和低频共模漏电流。研究结果表明:所提新型级联逆变器在一个工频周期内的高频共模电压保持恒定,且漏电流小于300m A,高频共模漏电流得到了有效抑制;同时,与非对称型CDBGCI相比,对称型CDBGCI具有更小的低频共模漏电流,且当n个双降压并网逆变器级联时,高频共模漏电流亦可得到有效抑制。研究可为级联型并网逆变器拓扑及其漏电流抑制研究提供参考。To suppress the leakage current of traditional dual-buck grid-connected inverters,a novel non-isolated cascaded dual-buck grid-connected inverter topology(CDBGCI)and dual-carrier sinusoidal pulse width modulation(DCSPWM)strategy were proposed.The high-frequency and low-frequency common-mode equivalent models of CDBGCI were established by the method of common-mode equivalent circuit,and the high-frequency and low-frequency common-mode leakage currents of the inverters are analyzed in detail,respectively.The research results show the high-frequency common-mode voltage of the novel cascaded inverter keeps a constant value during a power frequency period,and the leakage current is less than 300 mA,so the high-frequency common-mode current is effectively suppressed.Meanwhile,compared with asymmetric CDBGCI,symmetric CDBGCI has a smaller low-frequency common-mode leakage current,and the high-frequency common-mode leakage current can be suppressed when n dual buck grid-connected inverters are cascaded.Finally,the results can provide references for the research of cascade grid-connected inverter topology and leakage current suppression.

关 键 词：双降压式并网逆变器 级联逆变器 单极性双载波正弦脉宽调制 共模等效模型 漏电流 共模电压 

分 类 号：TM464[电气工程—电器]