Evaluation of Single Phase Transformerless Photovoltaic Inverters

Transormerless inverters are attractive solution for the grid connected photovoltaic (PV) systems.Unfortunately, it has issues on galvanic isolation between PV systems to the grid.When the galvanic isolation disappears from the PV inverter, leakage currents will flow in a resonant circuit formed by the ground capacitance, the converter, the ac filter and the grid.In order to avoid the leakage currents, various transformerless inverters have been proposed using different topologies to generate constant common mode voltage.In this paper, various recently-proposed transformerless PV inverters are investigated.Their performances are compared and analyzed.