A New Transformerless Configuration for Grid-Connected Photovoltaic Inverters.

Due to high efficiency, low cost and weight, transformerless inverters are widely used to deliver the photovoltaic (PV) energy to the grid. On the other hand, due to VDE standards, the leakage current between the stray capacitance of the PV array and the ground should be limited for the grid connected PV systems. In this case, some transformerless structures have been presented to restrict the leakage current. This paper presents a new transformerless structure for the PV inverters. The proposed structure keeps the common mode voltage constant in all switching periods and will suppress the leakage current. The performance of the proposed structure is verified by both mathematical and simulation (MATLAB/Simulink and PLECS Blockset) results.