基于旁路电容的L型滤波光伏并网逆变器漏电流抑制方法  

Leakage Current Suppression Solution of L-Filter-Based Photovoltaic Grid-Connected Inverter with Bypass Capacitors

作　　者：郭忠南[1] 郭小强[1] 李建[1] 沈虹[1] 王宝诚[1] 张纯江[1] Guo Zhongnan;Guo Xiaoqiang;Li Jian;Shen Hong;Wang Baocheng;Zhang Chunjiang(Department of Electrical Engineering Yanshan University Qinhuangdao 066004 China)

机构地区：[1]燕山大学电气工程学院,秦皇岛066004

出　　处：《电工技术学报》2017年第18期259-266,共8页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51477148);河北省引进留学人员资助项目(CL201622);河北省自然科学基金(E2015203407;E2016203156)资助项目

摘　　要：传统无变压器非隔离光伏并网逆变器系统中,通常采用增加交流旁路开关或直流旁路开关的方式解决系统漏电流问题。然而系统中加入旁路开关增加了系统成本,同时需要增加旁路开关的驱动电路,系统电路结构和控制方式复杂。为了解决该问题,提出一种基于旁路电容的漏电流抑制方案。首先以典型L滤波的光伏逆变器为研究对象,在分析其共模模型的基础上,提出旁路电容法实现漏电流抑制,并对不同旁路电容对系统共模特性的影响进行分析。该方案通过引入旁路电容改变系统共模回路,有效地滤除共模电压高频分量,消除系统寄生电容电压高频分量,从而实现漏电流的有效抑制。最后对提出的方案进行仿真和实验研究,验证了提出方案的可行性和有效性。In the traditional non-transformer PV grid-connected inverter systems,the additional AC-side or DC-side bypass switches are usually added into the inverters to solve the problem of the leakage current.However,the additional bypass switches increase the system cost,and also need extradriving circuits leading to complex circuit structure and complicated control.Therefore,a new solution based on the bypass capacitor is proposed to suppress the leakage current.The typical L-filter-based PV inverter is considered.Based on the common-mode model,the bypass capacitor scheme is proposed to reduce the leakage current.The effects of different values of bypass capacitances on the common-mode characteristics are discussed.The proposed scheme can effectively bypass the high frequency component of the common-mode voltage,and keep the parasitic capacitors voltage almost constant.Accordingly,the leakage current can be suppressed in an effective way.Finally,the experimental results verify the effectiveness of the proposed solution.

关 键 词：光伏系统 L型滤波器 并网逆变器 旁路电容 漏电流 

分 类 号：TM46[电气工程—电器]