单相无变压器光伏并网系统漏电流的研究  

Study on Leakage Current for Single Phase Transformerless PV Grid Connected System

作　　者：廖志凌[1] 宋中奇[1] 徐东[1] 

机构地区：[1]江苏大学电气信息工程学院,江苏镇江212013

出　　处：《电测与仪表》2013年第2期20-25,31,共7页Electrical Measurement & Instrumentation

基　　金：中国博士后基金资助项目(2012M521009);江苏省高校自然科学研究项目(11KJB470005);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：漏电流是研究非隔离型光伏并网系统的一个重要问题。漏电流谐振电路等效模型的建立对研究抑制漏电流至关重要。本文首先推导单相全桥并网逆变器漏电流谐振回路等效电路模型;然后详细分析了不同开关调制方式和滤波电感不对称分布对漏电流的影响,并指出电网电压对漏电流的影响不可忽略;最后介绍了一种新型无变压器拓扑结构,这种结构具有单极性调制和双极性调制优点,能够抑制共模漏电流的产生,同时提高系统的效率和并网电流质量。通过仿真和实验验证了分析结果的正确性。Leakage current is very important for researching non-isolated photovoltaic grid connected system, and the building of equivalent model resonant circuit of leakage current. In this paper, the resonant circuit of leakage current is crucial for researching suppression of the leakage current equivalent model of single phase grid connected inverter is deduced firstly. Then, the principle of the generation of leakage current is analyzed in detail. It is shown that leakage current is impacted by different switch modulation techniques and the asymmetric distribution of filter inductor. The paper points out that the influence of grid voltage on leakage current can not be ignore. Finally, a novel transformerless topology is introduced, which has the advantages of unipolar and bipolar modulation. The structure not only can suppress common-mode leakage current, but also improve system efficiency and the quality of ~rid current. The correctness of theoretical analysis is verified by simulation and experiment.

关 键 词：并网 无变压器 漏电流 逆变器 光伏 新型结构 

分 类 号：TM933[电气工程—电力电子与电力传动]