并联无隔离光伏并网逆变器漏电流和环流抑制研究

电气传动2016年第46卷第11期并联无隔离光伏并网逆变器漏电流和

环流抑制研究

张贞艳，高磊，张锦

（宿迁学院机电工程学院，江苏宿迁223800）

摘要：并联无隔离光伏并网逆变器会产生漏电流和环流问题。在分析三电平逆变器共模等效模型的基础上，采用改进型LCL 滤波器，将滤波器电容公共连接点和直流侧电容中点相连，能够滤除寄生电容电压的高频分量，减少共模漏电流。无隔离光伏并网逆变器并联能增加系统容量和可扩展性，但产生的零序环流会降低系统效率，而传统方法很难实现环流抑制。提出一种新型SVM 调制方法，通过实时改变零矢量作用时间实现精准控制，能够实现多台逆变器在电流不相等情况下的环流抑制。最后通过实验验证了所提拓扑和算法的有效性。

关键词：逆变器并联；漏电流；环流

中图分类号：TM464文献标识码：A DOI ：10.19457/j.1001-2095.20161106

Leakage Current and Circulating Current Reduction for Parallel Non -isolated

Grid -connected Inverters ZHANG Zhenyan ，GAO Lei ，ZHANG Jin

（School of Mechanical and Electrical Engineering ，Suqian College ，

Suqian 223800，Jiangsu ，China ）Abstract:The parallel non -isolated photovoltaic grid connected inverter can generate leakage current and circulating current.Analyzed the equivalent model of three -level inverter and usesd improved LCL filter whose capacitor common connection point connectes DC -side capacitor neutral point to filter out high frequency component of the parasitic capacitance voltage ，and to reduce common mode leakage currents.Non -isolated photovoltaic grid connected inverter could increase system capacity and scalability in parallel ，but the zero sequence circulating current could reduce the system efficiency ，and then the traditional method is difficult to achieve the circulation suppression.A novel SVM modulation method was proposed.This method could realize the precise control by changing the function time of zero vector in real time and could achieve circulating current restrain of more than one

inverters in the unequal current situation.Finally ，the experimental results show that the proposed topology and algorithm are effective.Key words:parallel inverters ；learage current ；circulating current 基金项目：宿迁市工业科技支撑计划项目（Z201542）；江苏省自然科学基金青年基金项目（BK20140586）；

江苏省高校品牌专业建设项目（PPZY2015C252）作者简介：张贞艳（1983-），女，硕士，讲师，Email ：zhenyanmm@https://www.360docs.net/doc/a917270789.html,

ELECTRIC DRIVE 2016Vol.46No.11

光伏发电已经成为世界上未来电力主要来

源，随着光伏发电系统的快速发展，对其可靠性

的要求越来越高［1-2］。非隔离型三相三电平并网

逆变系统因输出电流畸变率小、成本低等优点，

已经成为一种重要的趋势。但无隔离拓扑使太

阳能电池板和电网有了电气连接，会产生共模漏电流，增加并网电流谐波，甚至危害人身安全。因此研究非隔离型三电平并网逆变器具有至关重要的意义。随着光伏发电系统规模不断增大，单机光伏24

万方数据