Design of a new transformerless SepCuk inverter topology for grid connected photovoltaics

The elimination of transformer in solar inverter has reduced the size, weight and losses in the photovoltaic (PV) systems. But, the galvanic connection between PV module and the grid generates leakage current through the parasitic capacitance. This paper presents a new high efficient transformerless SepCuk inverter topology using a common grounding between the grid and PV module to meet the requirements of low leakage current, low harmonic distortion, low ripple, small volume and low cost. The leakage current and power quality depend on both the inverter topology and the control strategy. The main advantages of this inverter are the simple symmetrical control, common ground connection, low output current ripple, low harmonic distortion and high efficiency over a wide input voltage range. The design and simulation results verify that the proposed topology enables to achieve the peak efficiency of 96.73%.