Single-phase transformer-less buck-boost inverter with zero leakage current for PV systems

In this paper, a novel single-stage single-phase transformer-less buck-boost inverter is proposed, in which a reduced number of passive components is used. The proposed inverter combines the conventional buck, boost, and buck-boost converters in one converter in order to obtain a sinusoidal output voltage. In the proposed inverter, the input DC source and the load or grid have the same ground. Therefore, the leakage current problem in photovoltaic (PV) systems is eliminated. Furthermore, the proposed inverter supports the bi-directional power flow capability and it can inject reactive power to the load or the grid. The analysis, principle of operation, and modulation of the proposed inverter are introduced in this paper, where simulation results using MATLAB/Simulink models in both islanded and grid-tied modes of operation are shown.