EMI filter analysis for transformer-less photovoltaic inverter

This paper mainly discusses the EMI filter design methodology for photovoltaic inverter System. The novelty of the proposed methods lies in that it conducted an analysis of noise source and DC/AC side propagation path impedances of photovoltaic inverter system. EMI filter design method is proposed based on the impedance mismatching between the EMI filter impedances and noise source/load impedances. And four parts' filter choosing through offering different filter topologies are studied and compared. Simulation and experimental results give a firm support to the proposed method.