基于谐波提取的非隔离型并网光伏逆变器漏电流检测研究  

Research on Leakage Current Detection of Transformerless Grid-connected Photovoltaic Inverter Based on Harmonic Extraction

作　　者：康劲松[1] 张凤岗 KANG Jinsong;ZHANG Fenggang(School of Electronic and Information Engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学电子与信息工程学院,上海市杨浦区201804

出　　处：《中国电机工程学报》2020年第7期2113-2122,共10页Proceedings of the CSEE

摘　　要：与隔离型逆变器相比,非隔离型并网光伏逆变器体积小、成本低、效率高,但往往容易产生共模漏电流,相应安全隐患增大,相关标准对漏电流抑制及保护提出了严格要求。该文对上述情况的漏电流问题进行研究,详细分析单相Boost+HERIC逆变拓扑漏电流产生机理及漏电流谐波特征,然后分析漏电流检测硬件系统的局限性。在此基础上提出一种基于谐波提取的漏电流检测方法,有效解决了含有高频谐波漏电流检测不准确问题,实现了持续漏电流、突变漏电流的准确检测及保护。通过仿真及实验结果验证机理分析的正确性及侦测方法的有效性。该方法对含有高频漏电流的其他单相逆变拓扑及三相逆变拓扑均可使用。The transformerless grid-connected inverter has small size,low cost and high efficiency compared with transformer isolated inverter,but there’s more serious leakage current and the corresponding security risk increases,and the standard requirement of leakage current suppression and protection is strict.The leakage current issue in the above situation has been studied.The leakage current mechanism and harmonic characteristics of single-phase Boost+HERIC inverter topology has been analyzed in detail,and also the limitation of sampling and detecting hardware system.And then a leakage current detection method based on harmonic component extraction has been raised,which could solve the inaccurate detection problem of leakage current with high frequency harmonics,and achieve accurate detection and protection of continuous leakage current and sudden leakage current.Finally the validity of mechanism analysis and detection method has been verified by simulation and experimental results.In addition,this solution also can be applied to other single-phase and three-phase inverter with high frequency leakage current.

关 键 词：非隔离 并网光伏逆变器 高频谐振 共模漏电流 漏电流检测 谐波提取 

分 类 号：TM46[电气工程—电器]