Highly efficient GaN-based single-phase transformer-less PV grid-tied inverter

Photovoltaic (PV) systems have been the focus of many scientific researches recently. The interest in grid-tied PV transformer-less inverters has increased rapidly, because of their higher efficiency and lower cost compared to traditional line transformer inverters. In this paper, a new modified transformer-less topology derived from H5 inverter is proposed. The proposed topology is equipped with GaN HEMTs to fully benefits from the superior performance of WBG devices. Detailed operation modes, inverter structure and switching strategy of the proposed topology are investigated and compared to conventional H5 topology. Furthermore, a comparison of the performance of the proposed inverter with Si IGBT and GaN HEMTs was presented to analyze the benefits of using WBG devices. The simulation results validate the theoretical that the proposed topology reduces the conduction losses of the system. The simulation results show that GaN HEMTs based inverter provides lower power losses and more than 5% increase in the efficiency when compared to Si IGBTs based inverter. Thus, prove the effectiveness of the proposed inverter for grid-tied PV applications.