Elimination Of Leakage Current In Transformerless CMI Based PV System

In the renewable energy sources, PV system forms the reliable for power generation. Thus the transformerless CMI is considered to be the best alternative for low cost and high efficiency photovoltaic systems. Eliminating the leakage current is one of the most important issues for transformerless inverters in grid-connected photovoltaic system applications, where the technical challenge is how to keep the system common-mode voltage constant to reduce the leakage current. However due to the result of leakage current resulted from the parasitic capacitance efficiency and reliability is reduced. The leakage current caused due to common mode and differential mode voltage is also reduced in this paper is also analysed.So the problem due to transformerless PV inverter should be tackled carefully. In this paper the basic H –bridge is replaced by QZSI because it offers low impedance to high frequency harmonics. The QZSI circuit differs from that of a conventional ZSI in the LC impedance network interface between the source and inverters. Thus filter based suppression solution is used to reduce the leakage current. Thus analysis and solution for elimination of leakage current is done and verified using simulation tool MATLAB and result is obtained.