非隔离型逆变器直流侧电磁干扰滤波器研究

DC Side EMI Filter Analysis in Transformer-Less Inverter

随着半导体开关器件的快速发展,其在电力电子产品中的应用也越来越多,开关频率的升高和开关的开通与关断导致了严重的电磁干扰问题。在光伏逆变系统中,其自身的电磁干扰问题日益成为一个主要的制约因素。电磁干扰检测是产品投产前的最后一个关键步骤,因此其重要性不可忽略。对光伏逆变系统进行了建模,并对该系统中共模干扰的路径进行了完整的分析。基于阻抗不平衡原则给出了直流侧EMI滤波器设计过程。分别对4种常用的滤波器拓扑进行研究分析,并在光伏逆变器的直流侧分别加入这4种类型的滤波器,得到与之对应的仿真结果和实验结果,验证了理论分析的正确性。

This paper discusses the DC side electromagnetic interference(EMI) filter design methodology for photovoltaic inverter System. It conducted an analysis of noise source and propagation path impedances of photovoltaic inverter system. A DC side filter design method is proposed based on the impedance mismatching between the EMI filter impedances and noise source/load impedances. And four different filter topologies are studied and compared. Simulation and experimental results give a firm support to the proposed method. Lastly, it discussed the experimental results comparing with the simulation results and verified the correctness of theoretical analysis.